Patent Publication Number: US-9409243-B2

Title: Abrasive article and method of forming

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority under 35 U.S.C. §119(e) to U.S. Patent Application No. 61/813,815, entitled “Abrasive Article and Method of Forming”, by Rehrig et al., filed Apr. 19, 2013, which is assigned to the current assignee hereof and incorporated herein by reference in its entirety. This application further claims priority under 35 U.S.C. §119(e) to U.S. Patent Application No. 61/813,833, entitled “Abrasive Article and Method of Forming,” by Tian et al., filed Apr. 19, 2013, which is assigned to the current assignee hereof and incorporated herein by reference in its entirety. 
    
    
     FIELD OF THE DISCLOSURE 
     The following is directed to methods of forming abrasive articles, and particularly, single-layered abrasive articles. 
     DESCRIPTION OF THE RELATED ART 
     A variety of abrasive tools have been developed over the past century for various industries for the general function of removing material from a workpiece, including for example, sawing, drilling, polishing, cleaning, carving, and grinding. In particular reference to the electronics industry, abrasive tools suitable for slicing crystal ingots of material to form wafers is particularly pertinent. As the industry continues to mature, ingots have increasingly larger diameters, and it has become acceptable to use loose abrasives and wire saws for such works due to yield, productivity, affected layers, dimensional constraints and other factors. 
     Generally, wire saws are abrasive tools that include abrasive particles attached to a long length of wire that can be spooled at high speeds to produce a cutting action. While circular saws are limited to a cutting depth of less than the radius of the blade, wire saws can have greater flexibility allowing for cutting of straight or profiled cutting paths. 
     Various approaches have been taken in conventional fixed abrasive wire saws, such as producing these articles by sliding steel beads over a metal wire or cable, wherein the beads are separated by spacers. These beads may be covered by abrasive particles which are commonly attached by either electroplating or sintering. However, electroplating and sintering operations can be time consuming and thus costly ventures, prohibiting rapid production of the wire saw abrasive tool. Most of these wire saws have been used in applications, where kerf loss is not so dominating as in electronics applications, often to cut stone or marble. Some attempts have been made to attach abrasive particles via chemical bonding processes, such as brazing, but such fabrication methods reduce the tensile strength of the wire saw, and the wire saw becomes susceptible to breaking and premature failure during cutting applications under high tension. Other wire saws may use a resin to bind the abrasives to the wire. Unfortunately, the resin bonded wire saws tend to wear quickly and the abrasives are lost well before the useful life of the particles is realized, especially when cutting through hard materials. 
     Accordingly, the industry continues to need improved abrasive tools, particularly in the realm of wire sawing. 
     SUMMARY 
     According to a first aspect, an abrasive article may include a substrate comprising an elongated member, a first layer overlying the substrate, abrasive particles overlying the first layer; fillets connecting the first layer and the abrasive particles and a bonding layer overlying the abrasive particles, the first layer and the fillets. The fillets may have a fillet characteristic relative to an abrasive application. The fillet characteristic may be selected from the group consisting of a tacking factor (t fl /t f ), a fillet-to-particle factor (t f /d ab ), a fillet-to-bonding layer factor (t f /t bl ), a contact factor (A b /A f ), a fillet size variance (V f ), and a combination thereof. 
     For another aspect, an abrasive article may include a substrate comprising an elongated member, a first layer overlying the substrate, abrasive particles overlying the first layer, fillets connecting the first layer and the abrasive particles and a bonding layer overlying the abrasive particles, the first layer and the fillets. The fillets may have a fillet characteristic adapted to an abrasive application. The fillet characteristic may be selected from the group consisting of a tacking factor (t fl /t f ), a fillet-to-particle factor (t f /d ab ), a fillet-to-bonding layer factor (t f /t bl ), a contact factor (A b /A f ), a fillet size variance (V f ), and a combination thereof. 
     In yet another aspect, an abrasive article may include a substrate comprising an elongated member, a first layer overlying the substrate, abrasive particles overlying the first layer, fillets connecting the first layer and the abrasive particles, and a fillet characteristic comprising a fillet-to-particle factor (t f /d ab ) for an abrasive application of the abrasive article, wherein t f  represents an average maximum thickness of the fillets and d ab  represents a median particle size of the abrasive particles. 
     According to another aspect, an abrasive article may include a substrate comprising an elongated member, a first layer overlying the substrate, abrasive particles overlying the first layer, fillets connecting the first layer and the abrasive particles and a fillet characteristic comprising a tacking factor (t fl /t f ) for an abrasive application of the abrasive article, wherein t fl  represents an average thickness of the first layer and t f  represents an average maximum thickness of the fillets. 
     For yet another aspect, a method of forming an abrasive article may include providing a body including abrasive particles overlying a first layer, the first layer overlying a substrate, processing at least the substrate, the first layer, and the abrasive particles according to a controlled processing condition to form an abrasive article having a fillet characteristic relative to an abrasive application, the fillet characteristic selected from the group consisting of a tacking factor (t fl /t f ), a fillet-to-particle factor (t f /d ab ), a fillet-to-bonding layer factor (t f /t bl ), a contact factor (A b /A f ), a fillet size variance (V f ), and a combination thereof. The controlled processing condition may be selected from the group consisting of re-flow temperature, filler content, filler size, filler composition, average particle size of the abrasive particles, size distribution of the abrasive particles, content of the abrasive particles, composition of the abrasive particles, thickness of the first layer, composition of the first layer, atmospheric conditions, and a combination thereof. 
     According to another aspect, an abrasive article may comprise a substrate that may comprise an elongated member, a first layer overlying the substrate, abrasive particles overlying the first layer, fillets connecting the first layer and the abrasive particles and a tacking factor (t fl /t f ) of not greater than about 1.5, wherein t fl  represents an average thickness of the first layer and t f  represents an average thickness of the fillets. 
     For another aspect, an abrasive article may comprise a substrate that may comprise an elongated member, a first layer overlying the substrate, abrasive particles overlying the first layer, fillets connecting the first layer and the abrasive particles and a fillet-to-particle factor (t f /d ab ) of not greater than about 0.33, wherein t f  represents an average thickness of the fillets and d ab  represents an average particle size of the abrasive particles. 
     In yet another aspect, an abrasive article may comprise a substrate that may comprise an elongated member, a first layer overlying the substrate, abrasive particles overlying the first layer, fillets connecting the first layer and the abrasive particles and a bonding layer overlying the abrasive particles, the first layer and the fillets. A majority of the abrasive particles may have an undercut region defining a portion of the bonding layer extending under a portion of the abrasive particle between the abrasive particle and the tacking layer. 
     According to another aspect, an abrasive article may comprise a substrate that may comprise an elongated member, a first layer overlying the substrate, abrasive particles overlying the first layer, fillets connecting the first layer and the abrasive particles and a bonding layer overlying the abrasive particles, the first layer an the fillets. The abrasive particles may have a contact factor (A b /A f ) of at least about 1, wherein A b  represents an average percentage of a surface area of the abrasive particles in contact with the bonding layer and A f  represents an average percentage of the surface area of the abrasive particles in content with the fillets. 
     In yet another aspect, an abrasive article may comprise a substrate that may comprise an elongated member, a first layer overlying the substrate, abrasive particles overlying the first layer, fillets connecting the first layer and the abrasive particles, a bonding layer overlying the abrasive particles, the first layer and the fillets, at least one fillet characteristic selected from the group consisting of a tacking factor (t fl /t f ) of not greater than about 1.5, a fillet-to-particle factor (t f /d ab ) of not greater than about 0.33, a fillet-to-bonding layer factor (t f /t bl ) of not greater than about 100, a contact factor (A b /A f ) of at least about 1, a fillet size variance (V f ) of not greater than 60% or a combination thereof. The first layer may further comprise an average thickness of at least about 6% of an average particle size of the abrasive particles. 
     In still another aspect, a method of forming an abrasive article may comprise providing a body including abrasive particles overlying a first layer, the first layer overlying a substrate, processing at least the substrate, the first layer, and the abrasive particles according to a controlled processing condition to form an abrasive article having a fillet characteristic selected from the group consisting of a tacking factor (t fl /t f ) of not greater than about 1.5, a fillet-to-particle factor (t f /d ab ) of not greater than about 0.33, a fillet-to-bonding layer factor (t f /t bl ) of not greater than about 100, a contact factor (A b /A f ) of at least about 1, a fillet size variance (V f ) of not greater than 60% or a combination thereof. The controlled processing condition may be selected from the group consisting of re-flow temperature, filler content, filler size, filler composition, average particle size of the abrasive particles, size distribution of the abrasive particles, content of the abrasive particles, composition of the abrasive particles, thickness of the first layer, composition of the first layer, and a combination thereof. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure may be better understood, and its numerous features and advantages made apparent to those skilled in the art by referencing the accompanying drawings. 
         FIG. 1  includes a flow chart providing a process for forming an abrasive article in accordance with an embodiment. 
         FIG. 2A  includes a cross-sectional illustration of a portion of an abrasive article in accordance with an embodiment. 
         FIG. 2B  includes a cross-sectional illustration of a portion of an abrasive article including a barrier layer in accordance with an embodiment. 
         FIG. 2C  includes a cross-sectional illustration of a portion of an abrasive article including an optional coating layer in accordance with an embodiment. 
         FIG. 2D  includes a cross-sectional illustration of a portion of an abrasive article including a first type of abrasive particle and a second type of abrasive particle in accordance with an embodiment. 
         FIG. 3  includes a magnified image of an abrasive article formed according to an embodiment. 
         FIG. 4  includes a magnified image of an abrasive article formed according to another embodiment. 
         FIG. 5  includes a magnified image of an abrasive article formed according to another embodiment. 
         FIG. 6  includes a magnified image of an abrasive article formed according to yet another embodiment. 
         FIG. 7  includes a magnified image of an abrasive article formed according to still another embodiment. 
         FIG. 8  includes a magnified image of an abrasive article formed according to another embodiment. 
         FIG. 9  includes an illustration of an exemplary agglomerated particle according to an embodiment. 
         FIG. 10A  includes an illustration of a portion of an abrasive article according to an embodiment. 
         FIG. 10B  includes a cross-sectional illustration of a portion of the abrasive article of  FIG. 10A  according to an embodiment. 
         FIG. 10C  includes an illustration of a portion of an abrasive article according to an embodiment. 
         FIG. 11A  includes an illustration of a portion of an abrasive article including a lubricious material according to an embodiment. 
         FIG. 11B  includes an illustration of a portion of an abrasive article including a lubricious material according to an embodiment. 
         FIG. 12A  includes an illustration of a portion of an abrasive article including an abrasive particle having an exposed surface according to an embodiment. 
         FIG. 12B  includes a picture of a portion of an abrasive article including abrasive particles having exposed surfaces according to an embodiment. 
         FIG. 13  includes a cross-sectional picture of an abrasive article including abrasive agglomerates according to an embodiment. 
         FIG. 14  includes a chart of relative wafer break strength for wafers processed by a conventional sample and wafers processed by an abrasive article representative of an embodiment. 
         FIG. 15  includes an illustration of a reel-to-reel machine using an abrasive article to slice a workpiece. 
         FIG. 16  includes an illustration of an oscillation machine using an abrasive article to slice a workpiece. 
         FIG. 17  includes an exemplary plot of wire speed versus time for a single cycle of a variable rate cycle operation. 
         FIG. 18 a    includes an illustration of a portion of an abrasive article including fillets according to an embodiment. 
         FIG. 18 b    includes an illustration of a magnified portion of  FIG. 18   a.    
         FIG. 19 a    includes illustrations of an abrasive article including an undercut region according to an embodiment. 
         FIG. 19 b    includes an illustration of a magnified portion of  FIG. 19   a.    
         FIG. 20 a    includes illustrations of an abrasive article including an undercut region according to an embodiment. 
         FIG. 20 b    includes an illustration of a magnified portion of  FIG. 20   a.    
         FIG. 21  includes a magnified image of an abrasive article according to an embodiment. 
         FIG. 22  includes a magnified image of an abrasive article according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     The following is directed to abrasive articles, and particularly abrasive articles suitable for abrading and sawing through workpieces. In particular instances, the abrasive articles herein can form wire saws, which may be used in processing of sensitive, crystalline materials in the electronics industry, optics industry, and other associated industries. 
       FIG. 1  includes a flow chart providing a process of forming an abrasive article in accordance with an embodiment. The process can be initiated at step  101  by providing a substrate. The substrate can provide a surface for affixing abrasive materials thereto, thus facilitating the abrasive capabilities of the abrasive article. 
     In accordance with an embodiment, the process of providing a substrate can include a process of providing a substrate having an elongated body. In particular instances, the elongated body can have an aspect ratio of length:width of at least 10:1. In other embodiments, the elongated body can have an aspect ratio of at least about 100:1, such as at least 1000:1, or even at least about 10,000:1. The length of the substrate can be the longest dimension measured along a longitudinal axis of the substrate. The width can be a second longest (or in some cases smallest) dimension of the substrate measured perpendicular to the longitudinal axis. 
     Furthermore, the substrate can be in the form of elongated body having a length of at least about 50 meters. In fact, other substrates can be longer, having an average length of at least about 100 meters, such as at least about 500 meters, at least about 1,000 meters, or even 10,000 meters. 
     Furthermore, the substrate can have a width that may not be greater than about 1 cm. In fact, the elongated body can have an average width of not greater than about 0.5 cm, such as not greater than about 1 mm, not greater than about 0.8 mm, or even not greater than about 0.5 mm. Still, the substrate may have an average width of at least about 0.01 mm, such as at least about 0.03 mm. It will be appreciated that the substrate can have an average width within a range between any of the minimum and maximum values noted above. 
     In certain embodiments, the elongated body can be a wire having a plurality of filaments braided together. That is, the substrate can be formed of many smaller wires wound around each other, braided together, or fixed to another object, such as a central core wire. Certain designs may utilize plano wire as a suitable structure for the substrate. For example, the substrate can be a high strength steel wire having a break strength of at least about 3 GPa. The substrate break strength can be measured by ASTM E-8 for tension testing of metallic materials with capstan grips. The wire may be coated with a layer of a particular material, such as a metal, including for example, brass. 
     The elongated body can have a certain shape. For example, the elongated body can have a generally cylindrical shape such that it has a circular cross-sectional contour. In using elongated bodies having a circular cross-sectional shape, as viewed in a plane extending transversely to the longitudinal axis of the elongated body. 
     The elongated body can be made of various materials, including for example, inorganic materials, organic materials (e.g., polymers and naturally occurring organic materials), and a combination thereof. Suitable inorganic materials can include ceramics, glasses, metals, metal alloys, cements, and a combination thereof. In certain instances, the elongated body can be made of a metal or metal alloy material. For example, the elongated body may be made of a transition metal or transition metal alloy material and may incorporate elements of iron, nickel, cobalt, copper, chromium, molybdenum, vanadium, tantalum, tungsten, and a combination thereof. 
     Suitable organic materials can include polymers, which can include thermoplastics, thermosets, elastomers, and a combination thereof. Particularly useful polymers can include polyimides, polyamides, resins, polyurethanes, polyesters, and the like. It will further be appreciated that the elongated body can include natural organic materials, for example, rubber. 
     To facilitate processing and formation of the abrasive article, the substrate may be connected to a spooling mechanism. For example, the wire can be fed between a feed spool and a receiving spool. The translation of the wire between the feed spool and the receiving spool can facilitate processing, such that for example, the wire may be translated through desired forming processes to form the component layers of the finally-formed abrasive article while being translated from the feed spool to the receiving spool. 
     In further reference to the process of providing a substrate, it will be appreciated that the substrate can be spooled from a feed spool to a receiving spool at a particular rate to facilitate processing. For example, the substrate can be spooled at a rate of not less than about 5 m/min from the feed spool to the receiving spool. In other embodiments, the rate of spooling can be greater, such that it is at least about 8 m/min, at least about 10 m/min, at least about 12 m/min, or even at least about 14 m/min. In particular instances, the spooling rate may be not greater than about 500 m/min, such as not greater than about 200 m/min. The rate of spooling can be within a range between any of the minimum and maximum values noted above. It will be appreciated the spooling rate can represent the rate at which the finally-formed abrasive article can be formed. 
     After providing a substrate at step  101 , the process can continue at an optional step  102  that includes providing a barrier layer overlying the substrate. According to one aspect, the barrier layer can be overlying a peripheral surface of a substrate, such that it may be in direct contact with the peripheral surface of the substrate, and more particularly, can be bonded directly to the peripheral surface of the substrate. In one embodiment, the barrier layer can be bonded to the peripheral surface of the substrate and may define a diffusion bond region between the barrier layer and the substrate, characterized by an interdiffusion of at least one metal element of the substrate and one element of the barrier layer. In one particular embodiment, the barrier layer can be disposed between the substrate and other overlying layers, including for example, a first layer, a bonding layer, a coating layer, a layer of a first type of abrasive particles, a layer of a second type of abrasive particles, and a combination thereof. 
     The process of providing a substrate having a barrier layer can include sourcing such a construction or fabricating such a substrate and barrier layer construction. The barrier layer can be formed through various techniques, including for example, a deposition process. Some suitable deposition processes can include, printing, spraying, dip coating, die coating, plating (e.g., electrolyte or electroless), and a combination thereof. In accordance with an embodiment, the process of forming the barrier layer can include a low temperature process. For example, the process of forming the barrier layer can be conducted at a temperature of not greater than about 400° C., such as, not greater than about 375° C., not greater than about 350° C., not greater than about 300° C., or even not greater than about 250° C. Furthermore, after forming the barrier layer it will be appreciated that further processing can be undertaken including for example cleaning, drying, curing, solidifying, heat treating, and a combination thereof. The barrier layer can serve as a barrier to chemical impregnation of the core material by various chemical species (e.g., hydrogen) in subsequent plating processes. Moreover, the barrier layer may facilitate improved mechanical durability. 
     In one embodiment, the barrier layer can be a single layer of material. The barrier layer can be in the form of a continuous coating, overlying the entire peripheral surface of the substrate. The barrier material can include an inorganic material, such as a metal or metal alloy material. Some suitable materials for use in the barrier layer can include transition metal elements, including but not limited to tin, silver, copper, nickel, titanium, and a combination thereof. In one embodiment, the barrier layer can be a single layer of material consisting essentially of tin. In one particular instance, the barrier layer can contain a continuous layer of tin having a purity of at least 99.99% tin. Notably, the barrier layer can be a substantially pure, non-alloyed material. That is, the barrier layer can be a metal material (e.g., tin) made of a single metal material. 
     In other embodiments, the barrier layer can be a metal alloy. For example, the barrier layer can include a tin alloy, such as a composition including a combination of tin and another metal, including transition metal species such as copper, silver, and the like. Some suitable tin-based alloys can include tin-based alloys including silver, and particularly Sn96.5/Ag3.5, Sn96/Ag4, and Sn95/Ag5 alloys. Other suitable tin-based alloys can include copper, and particularly including Sn99.3/Cu0.7 and Sn97/Cu3 alloys. Additionally, certain tin-based alloys can include a percentage of copper and silver, including for example, Sn99/Cu0.7/Ag0.3, Sn97/Cu2.75/Ag0.25 and, Sn95.5/Ag4/Cu0.5 alloys. 
     In another aspect, the barrier layer can be formed from a plurality of discrete layers, including for example, at least two discrete layers. For example, the barrier layer can include an inner layer and an outer layer overlying the inner layer. According to an embodiment, the inner layer and outer layer can be directly contacting each other, such that the outer layer is directly overlying the inner layer and joined at an interface. Accordingly, the inner layer and outer layer can be joined at an interface extending along the length of the substrate. 
     In one embodiment, the inner layer can include any of the characteristics of the barrier layer described above. For example, the inner layer can include a continuous layer of material including tin, and more particularly, may consist essentially of tin. Moreover, the inner layer and outer layer can be formed of different materials relative to each other. That is, for example, at least one element present within one of the layers can be absent within the other layer. In one particular embodiment, the outer layer can include an element that is not present within the inner layer. 
     The outer layer can include any of the characteristics of the barrier layer described above. For example, the outer layer can be formed such that it includes an inorganic material, such as a metal or a metal alloy. More particularly, the outer layer can include a transition metal element. For example, in one certain embodiment, the outer layer can include nickel. In another embodiment, the outer layer can be formed such that it consists essentially of nickel. 
     In certain instances, the outer layer can be formed in the same manner as the inner layer, such as a deposition process. However, it is not necessary that the outer layer be formed in the same manner as the inner layer. In accordance with an embodiment, the outer layer can be formed through a deposition process including plating, spraying, printing, dipping, die coating, deposition, and a combination thereof. In certain instances, the outer layer of the barrier layer can be formed at relatively low temperatures, such as temperatures not greater than about 400° C., not greater than about 375° C., not greater than about 350° C., not greater than about 300° C., or even not greater than 250° C. According to one particular process, the outer layer can be formed though a non-plating process, such as die coating. Moreover, the processes used to form the outer layer may include other methods including for example heating, curing, drying, and a combination thereof. It will be appreciated that formation of the outer layer in such a manner may facilitate limiting the impregnation of unwanted species within the core and/or inner layer. 
     In accordance with an embodiment, the inner layer of the barrier layer can be formed to have a particular average thickness suitable for acting as a chemical barrier layer. For example, the barrier layer can have an average thickness of at least about 0.05 microns, such as least about 0.1 microns, at least about 0.2 microns, at least about 0.3 micron, or even at least about 0.5 microns. Still, the average thickness of the inner layer may be not greater than about 8 microns, such as not greater than about 7 microns, not greater than about 6 microns, not greater than about 5 microns, or even not greater than about 4 microns. It will be appreciated that the inner layer can have an average thickness within a range between any of the minimum and maximum thicknesses noted above. 
     The outer layer of the barrier layer can be formed to have a particular thickness. For example, in one embodiment the average thickness of the outer layer can be at least about 0.05 microns, such as least about 0.1 microns, at least about 0.2 microns, at least about 0.3 micron, or even at least about 0.5 microns. Still, in certain embodiments, the outer layer can have an average thickness that is not greater than about 12 microns, not greater than about 10 microns, not greater than about 8 microns, not greater than about 7 microns, not greater than about 6 microns, not greater than about 5 microns, not greater than about 4 microns, or even not greater than about 3 microns. It will be appreciated that the outer layer of the barrier layer can have an average thickness within a range between any of the minimum and maximum thicknesses noted above. 
     Notably, in at least embodiment, the inner layer can be formed to have a different average thickness than the average thickness of the outer layer. Such a design may facilitate improved impregnation resistance to certain chemical species while also providing suitable bonding structure for further processing. For example, in other embodiments the inner layer can be formed to have an average thickness that is greater than the average thickness of the outer layer. However, in alternative embodiments, the inner layer may be formed to have an average thickness so that it is less than the average thickness of the outer layer. 
     According to one particular embodiment, the barrier layer can have a thickness ratio [t i :t o ] between an average thickness of the inner layer (t i ) and an average thickness of the outer layer (t o ) that can be within a range between about 3:1 and about 1:3. In other embodiments, the thickness ratio can be within a range between about 2.5:1 and about 1:2.5, such as within a range between about 2:1 and about 1:2, within a range between about 1.8:1 and about 1:1.8, within a range between about 1.5:1 and about 1:1.5, or even within a range between about 1.3:1 and about 1:1.3. 
     Notably, the barrier layer (including at least the inner layer and outer layer) can be formed to have an average thickness that is not greater than about 10 microns. In other embodiments, the average thickness of the barrier layer may be less, such as not greater than about 9 microns, not greater than about 8 microns, not greater than about 7 microns, not greater than about 6 microns, not greater than about 5 microns, or even not greater than about 3 microns. Still, the average thickness of the barrier layer can be at least about 0.05 microns, such as least about 0.1 microns, at least about 0.2 microns, at least about 0.3 micron, or even at least about 0.5 microns. It will be appreciated that the barrier layer can have an average thickness within a range between any of the minimum and maximum thicknesses noted above. 
     Furthermore, the abrasive articles herein can form a substrate having a certain resistance to fatigue. For example, the substrates can have an average fatigue life of at least 300,000 cycles as measured through a Rotary Beam Fatigue Test or a Hunter Fatigue Test. The test can be a MPIF Std. 56. The rotary beam fatigue test measures the number of cycles up to wire break at designated stress (e.g. 700 MPa), i.e. constant stress or the stress under which the wire was not ruptured in a cyclic fatigue test with a number of repeating cycles of up to 10 6  (e.g. stress represents fatigue strength). In other embodiments, the substrate may demonstrate a higher fatigue life, such as least about 400,000 cycles, at least about 450,000 cycles, at least about 500,000 cycles, or even at least about 540,000 cycles. Still, the substrate may have a fatigue life that is not greater than about 2,000,000 cycles. 
     After optionally providing a barrier layer at step  102 , the process can continue at step  103 , which includes forming a first layer overlying a surface of the substrate. The process of forming a first layer can include a deposition process, including for example, spraying, printing, dipping, die coating, plating, and a combination thereof. The first layer can be bonded directly to the external surface of the substrate. In fact, the first layer can be formed such that it overlies a majority of the external surface of the substrate, and more particularly, can overlie essentially the entire external surface of the substrate. 
     The first layer may be formed such that it is bonded to the substrate in a manner that it defines a bonding region. The bonding region can be defined by an interdiffusion of elements between the first layer and the substrate. It will be appreciated that formation of the bonding region may not necessarily be formed at the moment when the first layer is deposited on the surface of the substrate. For example, the formation of a bonding region between the first layer and the substrate may be formed at a later time during processing, such as during a heat treatment process to facilitate bonding between the substrate and other component layers formed on the substrate. 
     Alternatively, the first layer may be formed such that it directly contacts at least a portion of the barrier layer, such as the exterior peripheral surface of the barrier layer. In a particular embodiment, the first layer can be bonded directly to the barrier layer, and more particularly, bonded directly to an outer layer of the barrier layer. As noted above, the first layer may be formed such that it is bonded to the barrier layer in a manner that it defines a bonding region. The bonding region can be defined by an interdiffusion of elements between the first layer and the barrier layer. It will be appreciated that formation of the bonding region may not necessarily be formed at the moment when the first layer is deposited on the surface of the barrier layer. For example, the formation of a bonding region between the first layer and the barrier may be formed at a later time during processing, such as during a heat treatment process to facilitate bonding between the substrate and other component layers formed on the substrate. 
     Yet in another embodiment, it will be appreciated that the first layer can be made of material suitable for use as a first layer and a barrier layer. For example, the first layer can have the same materials and construction of the barrier layer, facilitating improved mechanical properties of the substrate and may include a material of a first layer in any of the embodiments herein suitable for tacking and binding of abrasive particles for further processing. The barrier layer can be a discontinuous layer having coated regions and gaps in the barrier layer. The first layer can overlie the coated regions and the gaps in the barrier layer where the underlying substrate may be exposed. 
     In one particular embodiment, the first layer can be disposed between the substrate and other overlying layers, including for example, a bonding layer, a coating layer, a layer of a first type of abrasive particles, a layer of a second type of abrasive particles, and a combination thereof. Moreover, it will be appreciated that the first layer can be disposed between the barrier layer and other overlying layers, including for example, a bonding layer, a coating layer, a layer of a first type of abrasive particles, a layer of a second type of abrasive particles, and a combination thereof. 
     In accordance with an embodiment, the first layer can be formed from a metal, metal alloy, metal matrix composite, and a combination thereof. In one particular embodiment, the first layer can be formed of a material including a transition metal element. For example, the first layer can be a metal alloy including a transition metal element. Some suitable transition metal elements can include, lead, silver, copper, zinc, indium, tin, titanium, molybdenum, chromium, iron, manganese, cobalt, niobium, tantalum, tungsten, palladium, platinum, gold, ruthenium, and a combination thereof. According to one particular embodiment, the first layer can be made of a metal alloy including tin and lead. In particular, such metal alloys of tin and lead may contain a majority content of tin as compared to lead, including but not limited to, a tin/lead composition of at least about 60/40. 
     In another embodiment, the first layer can be made of a material having a majority content of tin. In fact, in certain abrasive articles, the first layer may consist essentially of tin. The tin, alone or in the solder, can have a purity of at least about 99%, such as at least about 99.1%, at least about 99.2%, at least about 99.3%, at least about 99.4%, at least about 99.5%, at least about 99.6%, at least about 99.7%, at least about 99.8%, or at least about 99.9%. In another aspect, the tin can have a purity of at least about 99.99%. 
     According to at least one embodiment, the first layer may be formed via a plating process. The plating process may be an electrolyte plating process or an electroless plating process. In one particular instance, the first layer can be formed by traversing the substrate through a certain plating material, which can include a bath that can produce a first layer comprising a matte tin layer. The matte tin layer can be a plated layer having particular features. For example, the matte tin layer can have an organic content of not greater than about 0.5 wt % for a total weight of the plated material (i.e., the first layer). Organic content can include compositions include carbon, nitrogen, sulfur, and a combination thereof. In certain other instances, the content of organic material in the matte tin layer can be not greater than about 0.3 wt %, such as not greater than about 0.1 wt %, not greater than about 0.08 wt %, or even not greater than about 0.05 wt % for the total weight of the first layer. According to one embodiment, the matte tin layer can be essentially free of organic brighteners and organic grain refiners. Moreover, the matte tin layer may have a purity of at least about 99.9%. 
     The matte tin layer may be made from a particular plating material having certain features. For example, the plating material can have an organic content of not greater than about 0.5 wt % for a total weight of the plated material in the bath. Organic content can include compositions include carbon, nitrogen, sulfur, and a combination thereof. In certain other instances, the content of organic material in the plated material can be not greater than about 0.3 wt %, such as not greater than about 0.1 wt %, not greater than about 0.08 wt %, or even not greater than about 0.05 wt % for the total weight of the plating material. According to one embodiment, the plating material can be essentially free of organic brighteners and organic grain refiners. Moreover, the plating material may have a purity of at least about 99.9%. 
     Moreover, the matte tin layer may have a particular average grain size of tin material. For example, the matte tin layer can have an average grain size of at least about 0.1 microns, such as at least about 0.2 microns, at least about 0.5 microns, or even at least about 1 micron. Still, in one non-limiting embodiment, the matte tin layer can have an average grain size of tin of not greater than about 50 microns, such as not greater than about 25 microns, not greater than about 15 microns, or not greater than about 10 microns. It will be appreciated that the average grain size of the grains of the matte tin layer can be within a range between any of the above minimum and maximum values. 
     In accordance with an embodiment, the first layer can be a solder material. It will be appreciated that a solder material may include a material having a particular melting point, such as not greater than about 450° C. Solder materials are distinct from braze materials, which generally have significantly higher melting points than solder materials, such as greater than 450° C., and more typically, greater than 500° C. Furthermore, brazing materials may have different compositions. In accordance with an embodiment, the first layer of the embodiments herein may be formed of a material having a melting point of not greater than about 400° C., such as not greater than about 375° C., not greater than about 350° C., not greater than about 300° C., or not greater than about 250° C. Still, the first layer may have a melting point of at least about 100° C., such as at least about 125° C., at least about 150° C., or even at least about 175° C. It will be appreciated that the first layer can have a melting point within a range between any of the minimum and maximum temperatures noted above. 
     According to one embodiment, the first layer can include a same material as the barrier layer, such that the compositions of the barrier layer and the first layer share at least one element in common. In yet an alternative embodiment, the barrier layer and the first layer can be entirely different materials. 
     According to at least one embodiment, the formation of the first layer can include formation of additional layers overlying the first layer. For example, in one embodiment, the formation of the first layer includes formation of an additional layer overlying the first layer to facilitate further processing. The additional layer can be overlying the substrate, and more particularly, in direct contact with at least a portion of the first layer. 
     The additional layer can include a flux material, which facilitates melting of the material of the first layer and further facilitates attachment of abrasive particles on the first layer. The flux material can be in the form of a generally uniform layer overlying the first layer, and more particularly, in direct contact with the first layer. The additional layer in the form of a flux material can comprise a majority content of flux material. In certain instances, essentially all of the additional layer can consist of the flux material. 
     The flux material can be in the form of a liquid or paste. According to one embodiment, the flux material can be applied to the first layer using a deposition process such as spraying, dipping, painting, printing, brushing, and a combination thereof. For at least one exemplary embodiment, the flux material can include a material such as a chloride, an acid, a surfactant, a solvent, water and a combination thereof. In one particular embodiment, the flux can include hydrochloride, zinc chloride, and a combination thereof. 
     After forming the first layer at step  103 , the process can continue at step  104  by placing abrasive particles on the first layer. Reference herein to abrasive particles is reference to any one of the multiple types of abrasive particle described herein, including for example a first type of abrasive particle or a second type of abrasive particle. The types of abrasive particles are described in more detail herein. In some instances, depending upon the nature of the process, the abrasive particles can be in direct contact with the first layer. More particularly, the abrasive particles can be in direct contact with an additional layer, such as a layer comprising a flux material, overlying the first layer. In fact, the additional layer of material comprising the flux material can have a natural viscosity and adhesive characteristic that facilitates holding the abrasive particles in place during processing, until further processes are conducted to permanently bond the abrasive particles in place relative to the first layer. 
     Suitable methods of providing the abrasive particles on the first layer, and more particularly, on the additional layer comprising the flux material, can include various deposition methods, including but not limited to, spraying, gravity coating, dipping, die coating, dip coating, electrostatic coating, plating, and a combination thereof. Particularly useful methods of applying the abrasive particles can include a spraying process, conducted to apply a substantially uniform coating of abrasive particles onto the additional layer comprising the flux material. 
     In an alternative embodiment, the process of providing the abrasive particles can include the formation of a mixture comprising the additional material, which may include a flux material and the abrasive particles. In one particular process according to an embodiment herein, the process of providing the abrasive particles can include dip coating the abrasive particles on the tacking film. Dip coating can include translating the abrasive article through a mixture or slurry comprising at least the flux material and the abrasive particles. As such, the abrasive particles can be applied to the first layer and the additional layer comprising the flux material can be formed simultaneously. 
     According to one particular embodiment, the process of applying the additional coating, which may optionally include simultaneous application of the abrasive particles, depending upon the components of the mixture, can include a die coating process. In certain instances, the abrasive article can be translated through a mixture comprising the additional material (and optionally the abrasive particles) and translated through a mechanism (e.g., a die opening having controlled dimensions) to control the thickness of the additional layer. 
     According to an embodiment, particular aspects of the slurry and the dip coating process may be controlled to facilitate the formation of a suitable abrasive article. For example, in one embodiment the slurry can be a Newtonian fluid having a viscosity of at least 0.1 mPa s and no more than 1 Pa s at a temperature of 25° C. and a shear rate of 1 l/s. The slurry can also be a non-Newtonian fluid having a viscosity of at least 1 mPa s and no more than 100 Pa s, or even not greater than about 10 Pa s, at the shear rate of 10 l/s as measured at a temperature of 25° C. Viscosity can be measured using a TA Instruments AR-G2 rotational rheometer using a set up of 25 mm parallel plates, a gap of approximately 2 mm, shear rates of 0.1 to 10 l/s at a temperature of 25° C. 
     The process of providing the abrasive particles may also include controlling the abrasive particle concentration (e.g., the first abrasive particle concentration, the second abrasive particle concentration, or a combination of first and second abrasive concentrations). Controlling the abrasive particle concentration can include at least one of controlling an amount of abrasive particles delivered to the first layer, a ratio of the amount of abrasive particles relative to an amount of the first layer, a ratio of the amount of abrasive particles relative to an amount of an additional layer comprising the flux material, a ratio of the amount of abrasive particles relative to the viscosity of the slurry, a position of the abrasive particles on the first layer, a position of the first type of abrasive particle on the first layer relative to a location of a second type of abrasive particle, a force of delivering the abrasive particles, and a combination thereof. In particular instances, controlling the abrasive particle concentration can include measuring the abrasive particle concentration during forming. Various methods of measuring can be used including mechanical, optical, and a combination thereof. Additionally, in certain embodiments, the process of controlling the abrasive particle concentration can include measuring the distribution of the abrasive particles on the substrate during forming the abrasive article and adjusting the amount of the abrasive particles deposited on the first layer based on a measured value. In an exemplary embodiment, the process of adjusting the amount of abrasive particles deposited on the substrate can include changing a deposition parameter based on the measured value, including for example, in the context of providing the abrasive particles via a spraying process, adjusting the process parameters of the spray nozzle (e.g., force of material being ejected, weight ratio of abrasive particles to other components, etc.). Some suitable examples of deposition parameters can include weight ratio of abrasive particles to carrier material (e.g., flux), delivery force used to apply abrasive particles, temperature, content of organics in carrier material or on substrate, atmospheric conditions of forming environment, and the like. 
     For at least one embodiment, the process of depositing the abrasive particles onto the first layer can include deposition, which more particularly can include spraying the abrasive particles onto the first layer. In certain processes, spraying can include using more than one nozzle. In more particular designs, more than one nozzle for delivery of the abrasive particles can be used, wherein the nozzles are arranged around the substrate in axis-symmetrical pattern. 
     Alternatively, the process of depositing the abrasive particles on the first layer can include translating the abrasive article having the first layer through a bed of abrasive particles. In certain instances, the bed can be a fluidized bed of abrasive particles. 
     Reference herein to abrasive particles can include reference to multiple types of abrasive particles, including for example, a first type of abrasive particle and a second type of abrasive particle different than the first type. According to at least one embodiment, the first type of abrasive particle can be different than the second type of abrasive particle based on at least one particle characteristic of the group consisting of hardness, friability, toughness, particle shape, crystalline structure, average particle size, composition, particle coating, grit size distribution, and a combination thereof. Moreover, it will be appreciated that reference herein to abrasive particles can include agglomerated particles including a binder phase, unagglomerated particles, and a combination thereof, including for instance, a first type that is an agglomerated particle and a second type that is an unagglomerated particle. 
     The first type of abrasive particle can include a material such as an oxide, a carbide, a nitride, a boride, an oxynitride, an oxyboride, diamond, and a combination thereof. In certain embodiments, the first type of abrasive particle can incorporate a superabrasive material. For example, one suitable superabrasive material includes diamond. In particular instances, the first type of abrasive particle can consist essentially of diamond. 
     Moreover, the second type of abrasive particle can include a material such as an oxide, a carbide, a nitride, a boride, an oxynitride, an oxyboride, diamond, and a combination thereof. In certain embodiments, the second type of abrasive particle can incorporate a superabrasive material. For example, one suitable superabrasive material includes diamond. In particular instances, the second type of abrasive particle can consist essentially of diamond. 
     In one embodiment, the first type of abrasive particle can include a material having a Vickers hardness of at least about 10 GPa. In other instances, the first type of abrasive particle can have a Vickers hardness of at least about 25 GPa, such as at least about 30 GPa, at least about 40 GPa, at least about 50 GPa, or even at least about 75 GPa. Still, in at least one non-limiting embodiment, the first type of abrasive particle can have a Vickers hardness that is not greater than about 200 GPa, such as not greater than about 150 GPa, or even not greater than about 100 GPa. It will be appreciated that the first type of abrasive particle can have a Vickers hardness within a range between any of the minimum and maximum values noted above. 
     The second type of abrasive particle can include a material having a Vickers hardness of at least about 10 GPa. In other instances, the second type of abrasive particle can have a Vickers hardness of at least about 25 GPa, such as at least about 30 GPa, at least about 40 GPa, at least about 50 GPa, or even at least about 75 GPa. Still, in at least one non-limiting embodiment, the second type of abrasive particle can have a Vickers hardness that is not greater than about 200 GPa, such as not greater than about 150 GPa, or even not greater than about 100 GPa. It will be appreciated that the second type of abrasive particle can have a Vickers hardness within a range between any of the minimum and maximum values noted above. 
     In certain instances, the first type of abrasive particle can have a first average hardness (H1) and the second type of abrasive particle can have a second average hardness (H2) that is different than the first average hardness. In some examples, the first average hardness can be greater than the second average hardness. In still other instances, the first average hardness can be less than the second average hardness. According to yet another embodiment, the first average hardness can be substantially the same as the second average hardness. 
     For at least one aspect, the first average hardness can be at least about 5% different than the second average hardness based on the absolute value of the equation ((H1−H2)/H1)×100%. In one embodiment, the first average hardness is at least about 10% different, at least about 20% different, at least about 30% different, at least about 40% different, at least about 50% different, at least about 60% different, at least about 70% different, at least about 80% different, or even at least about 90% different than the second average hardness. Yet, in another non-limiting embodiment, the first average hardness may be not greater than about 99% different, such as not greater than about 90% different, not greater than about 80% different, not greater than about 70% different, not greater than about 60% different, not greater than about 50% different, not greater than about 40% different, not greater than about 30% different, not greater than about 20% different, not greater than about 10% different than the second average hardness. It will be appreciated that the difference between the first average hardness and the second average hardness can be within a range between any of the above minimum and maximum percentages. 
     In at least one embodiment, the first type of abrasive particle can have a first average particle size (P1) different than a second average particle size (P2) of the second type of abrasive particle. In some instances, the first average particle size can be greater than the second average particle size. In still other embodiment, the first average particle size can be less than the second average particle size. According to yet another embodiment, the first average particle size can be substantially the same as the second average particle size. 
     For a particular embodiment, the first type of abrasive particle can have a first average particle size (P1) and the second type of abrasive particle can have a second average particle size (P2), wherein the first average particle size is at least about 5% different than the second average particle size based on the absolute values of the equation ((P1−P2)/P1)×100%. In one embodiment, the first average particle size is at least about 10% different, such as at least about 20% different, at least about 30% different, at least about 40% different, at least about 50% different, at least about 60% different, at least about 70% different, at least about 80% different, or even at least about 90% different than the second average particle size. Yet, in another non-limiting embodiment, the first average particle size may be not greater than about 99% different, such as not greater than about 90% different, not greater than about 80% different, not greater than about 70% different, not greater than about 60% different, not greater than about 50% different, not greater than about 40% different, not greater than about 30% different, not greater than about 20% different, not greater than about 10% different than the second average particle size. It will be appreciated that the difference between the first average particle size and the second average particle size can be within a range between any of the above minimum and maximum percentages. 
     According to at least one embodiment, the first type of abrasive particle can have a first average particle size of not greater than about 500 microns, such as not greater than about 300 microns, not greater than about 200 microns, not greater than about 150 microns, or even not greater than about 100 microns. Yet, in a non-limiting embodiment, the first type of abrasive particle may have a first average particle size of at least about 0.1 microns, such as at least about 0.5 microns, at least about 1 micron, at least about 2 microns, at least about 5 microns, or even at least about 8 microns. It will be appreciated that the first average particle size can be within a range between any of the above minimum and maximum percentages. 
     For certain embodiments, the second type of abrasive particle can have a second average particle size of not greater than about 500 microns, such as not greater than about 300 microns, not greater than about 200 microns, not greater than about 150 microns, or even not greater than about 100 microns. Yet, in a non-limiting embodiment, the second type of abrasive particle may have a second average particle size of at least about 0.1 microns, such as at least about 0.5 microns, at least about 1 micron, at least about 2 microns, at least about 5 microns, or even at least about 8 microns. It will be appreciated that the second average particle size can be within a range between any of the above minimum and maximum percentages. 
     For a particular embodiment, the first type of abrasive particle can have a first average friability (F1) and the second type of abrasive particle can have a second average friability (F2). Moreover, the first average friability can be different than the second average friability, including greater than or less than the second average friability. Still, in another embodiment, the first average friability can be substantially the same as the second average friability. 
     According to one embodiment, the first average friability can be at least about 5% different than the second average friability based on the absolute values of the equation ((F1−F2)/F1)×100%. In one embodiment, the first average friability is at least about 10% different, such as at least about 20% different, at least about 30% different, at least about 40% different, at least about 50% different, at least about 60% different, at least about 70% different, at least about 80% different, or even at least about 90% different than the second average friability. Yet, in another non-limiting embodiment, the first average friability may be not greater than about 99% different, such as not greater than about 90% different, not greater than about 80% different, not greater than about 70% different, not greater than about 60% different, not greater than about 50% different, not greater than about 40% different, not greater than about 30% different, not greater than about 20% different, not greater than about 10% different than the second average friability. It will be appreciated that the difference between the first average friability and the second average friability can be within a range between any of the above minimum and maximum percentages. 
     For a particular embodiment, the first type of abrasive particle can have a first average toughness (T1) and the second type of abrasive particle can have a second average toughness (T2). Moreover, the first average toughness can be different than the second average toughness, including greater than or less than the second average toughness. Still, in another embodiment, the first average toughness can be substantially the same as the second average toughness. 
     According to one embodiment, the first average toughness can be at least about 5% different than the second average toughness based on the absolute values of the equation ((T1−T2)/T1)×100%. In one embodiment, the first average toughness is at least about 10% different, such as at least about 20% different, at least about 30% different, at least about 40% different, at least about 50% different, at least about 60% different, at least about 70% different, at least about 80% different, or even at least about 90% different than the second average toughness. Yet, in another non-limiting embodiment, the first average toughness may be not greater than about 99% different, such as not greater than about 90% different, not greater than about 80% different, not greater than about 70% different, not greater than about 60% different, not greater than about 50% different, not greater than about 40% different, not greater than about 30% different, not greater than about 20% different, not greater than about 10% different than the second average toughness. It will be appreciated that the difference between the first average toughness and the second average toughness can be within a range between any of the above minimum and maximum percentages. 
     Particular abrasive articles of the embodiments herein may utilize particular contents of the first type of abrasive particle and the second type of abrasive particle relative to each other, which may facilitate improved performance. For example, the first type of abrasive particle can be present in a first content and the second type of abrasive particle may be present in a second content. According to one embodiment, the first content can be greater than the second content. Yet, in other instances, the second content can be greater than the first content. For still another embodiment, the first content can be substantially the same as the second content. 
     In at least one embodiment, the first type of abrasive particle can be present in a first content and the second type of abrasive particle can be present in a second content, and the relative amount of the first content to the second content based upon a numerical particle count can define a particle count ratio (FC:SC), wherein FC represents the first particle count content and SC represents the second particle count content. According to one embodiment, the particle count ratio (FC:SC) can be not greater than about 100:1, such as not greater than about 50:1, not greater than about 20:1, not greater than about 10:1, not greater than about 5:1, or even not greater than about 2:1. In one particular instance, the particle count ratio (FC:SC) can be approximately 1:1, such that the first content and second content (based on particle count) are substantially the same or essentially the same. Still, in another non-limiting embodiment, the particle count ratio (FC:SC) can be at least about 2:1, such as at least about 5:1, at least about 10:1, at least about 20:1, at least about 50:1, at least about 100:1. It will be appreciated that the particle count ratio can be defined by a range between any two ratios noted above. 
     According to another embodiment, the particle count ratio (FC:SC) can be not greater than about 1:100, such as not greater than about 1:50, not greater than about 1:20, not greater than about 1:10, not greater than about 1:5, not greater than about 1:2. Still, in another non-limiting embodiment, the particle count ratio (FC:SC) can be at least about 1:2, such as at least about 1:5, at least about 1:10, at least about 1:20, at least about 1:50, at least about 1:100. It will be appreciated that the particle count ratio can be defined by a range between any two ratios noted above. For example, the particle count ratio can be between 1:1 and 1:100, such as between about 1:2 and 1:100. In other instances, the particle count ratio may between 100:1 and 1:1, or even between about 100:1 and 2:1. Still, in a non-limiting embodiment, the particle count ratio may be between about 100:1 and 1:100, such as between about 50:1 and 1:50, such as between about 20:1 and 1:20, between about 10:1 and 1:10, between about 5:1 and 1:5, or even between about 2:1 and 1:2. 
     The content of the first type of abrasive particle and the second type of abrasive particle may be measured in another manner besides the particle count. For example, the first type of abrasive particle can be measured by a weight percent of the first type of abrasive particle for the total content of abrasive particles (P1 wt %) and the second type of abrasive particle can be measured by the weight percent of the second type of abrasive particle for the total content of abrasive particles (P2 wt %). According to one embodiment, the abrasive article can have a particle weight ratio (P1 wt %:P2 wt %), as defined by the relative weight percent of the first type of abrasive particle to the weight percent of the second type of abrasive particle. In one particular embodiment, the particle weight ratio can be not greater than about 100:1, such as not greater than about 50:1, not greater than about 20:1, not greater than about 10:1, not greater than about 5:1, not greater than about 2:1. Still, in one instance, the particle weight ratio (P1 wt %:P2 wt %) can be approximately 1:1, such that the first content and second content (based on weight percent) are substantially the same or essentially the same. Still, in another non-limiting embodiment, the particle weight ratio (P1 wt %:P2 wt %) can be at least about 2:1, such as at least about 5:1, at least about 10:1, at least about 20:1, at least about 50:1, at least about 100:1. It will be appreciated that the particle weight ratio (P1 wt %:P2 wt %) can be defined by a range between any two ratios noted above. 
     According to another embodiment, the particle weight ratio (P1 wt %:P2 wt %) can be not greater than about 1:100, such as not greater than about 1:50, not greater than about 1:20, not greater than about 1:10, not greater than about 1:5, not greater than about 1:2. Still, in another non-limiting embodiment, the particle weight ratio (P1 wt %:P2 wt %) can be at least about 1:2, such as at least about 1:5, at least about 1:10, at least about 1:20, at least about 1:50, at least about 1:100. It will be appreciated that the particle weight ratio (P1 wt %:P2 wt %) can be defined by a range between any two ratios noted above. For example, the particle weight ratio (P1 wt %:P2 wt %) can be between 1:1 and 1:100, such as between about 1:2 and 1:100. In other instances, the particle weight ratio (P1 wt %:P2 wt %) may between 100:1 and 1:1, or even between about 100:1 and 2:1. Still, in a non-limiting embodiment, the particle weight ratio (P1 wt %:P2 wt %) may be between about 100:1 and 1:100, such as between about 50:1 and 1:50, such as between about 20:1 and 1:20, between about 10:1 and 1:10, between about 5:1 and 1:5, or even between about 2:1 and 1:2. 
     The first type of abrasive particle can have a particular shape, such as a shape from the group including elongated, equiaxed, ellipsoidal, boxy, rectangular, triangular, irregular, and the like. The second type of abrasive particle may also have a particular shape, including for example, elongated, equiaxed, ellipsoidal, boxy, rectangular, triangular, and the like. It will be appreciated that the shape of the first type of abrasive particle can be different than the shape of the second type of abrasive particle. Alternatively, the first type of abrasive particle can have a shape that is substantially the same as the second type of abrasive particle. 
     Moreover, in certain instances, the first type of abrasive particle can have a first type of crystalline structure. Some exemplary crystalline structures can include multicrystalline, monocrystalline, polygonal, cubic, hexagonal, tetrahedral, octagonal, complex carbon structure (e.g., Bucky-ball), and a combination thereof. Additionally, the second type of abrasive particle can have a particular crystalline structure, such as multicrystalline, monocrystalline, cubic, hexagonal, tetrahedral, octagonal, a complex carbon structure (e.g., Bucky-ball), and a combination thereof. It will be appreciated that the crystalline structure of the first type of abrasive particle can be different than the crystalline structure of the second type of abrasive particle. Alternatively, the first type of abrasive particle can have a crystalline structure that is substantially the same as the second type of abrasive particle. 
     For a particular embodiment, the first type of abrasive particle can be defined by a wide grit size distribution, wherein at least 80% of the first type of abrasive particle has an average particle size contained within a range of at least about 30 microns over a range of average particle sizes between about 1 micron to about 100 microns. Additionally, the second type of abrasive particle may also be defined by a wide grit size distribution wherein at least 80% of the second type of abrasive particle has an average particle size contained within a range of at least about 30 microns over a range of average particle sizes between about 1 micron to about 100 microns. 
     In one embodiment, the wide grit size distribution can be a bimodal particle size distribution, wherein the bimodal particle size distribution comprises a first mode defining a first median particle size (M1) and a second mode defining a second median particle size (M2) that is different than the first median particle size. According to a particular embodiment, the first median particle size and second median particle size are at least 5% different based on the equation ((M1−M2)/M1)×100%. In still other embodiments, the first median particle size and the second median particle size can be at least about 10% different, such as at least about 20% different, at least about 30% different, at least about 40% different, at least about 50% different, at least about 60% different, at least about 70% different, at least about 80% different, or even at least about 90% different. Yet, in another non-limiting embodiment, the first median particle size may be not greater than about 99% different, such as not greater than about 90% different, not greater than about 80% different, not greater than about 70% different, not greater than about 60% different, not greater than about 50% different, not greater than about 40% different, not greater than about 30% different, not greater than about 20% different, or even not greater than about 10% different than the second median particle size. It will be appreciated that the difference between the first median particle size and the second median particle size can be within a range between any of the above minimum and maximum percentages. 
     For a particular embodiment, the first type of abrasive particle can include an agglomerated particle. More particularly, the first type of abrasive particle can consist essentially of an agglomerated particle. Moreover, the second type of abrasive particle may include an unagglomerated particle, and more particularly, may consist essentially of an unagglomerated particle. Still, it will be appreciated that the first and second type of abrasive particles may include an agglomerated particle or an unagglomerated particle. The first type of abrasive particle can be an agglomerated particle having a first average particle size and the second type of abrasive particle including an unagglomerated particle having a second average particle size different than the first average particle size. Notably, for one embodiment, the second average particle size can be substantially the same as the first average particle size. 
     According to an embodiment, an agglomerated particle can include abrasive particles bonded to each other by a binder material. Some suitable examples of a binder material can include an inorganic material, an organic material, and a combination thereof. More particularly, the binder material may be a ceramic, a metal, a glass, a polymer, a resin, and a combination thereof. In at least one embodiment, the binder material can be a metal or metal alloy, which may include one or more transition metal elements. According to an embodiment, the binder material can include at least one metal element from a component layer of the abrasive article, including for example, the barrier layer, the first layer, the bonding layer, the coating layer, and a combination thereof. For at least one abrasive article herein, at least a portion of the binder material can be the same material as used in the first layer, and more particularly, essentially all of the binder material can be the same material of the first layer. In yet another aspect, at least a portion of the binder material can be the same material as a bonding layer overlying the abrasive particles, and more particularly, essentially all of the binder material can be the same as the bonding layer. 
     In a more particular embodiment, the binder can be a metal material that includes at least one active binding agent. The active binding agent may be an element or composition including a nitride, a carbide, and combination thereof. One particular exemplary active binding agent can include a titanium-containing composition, a chromium-containing composition, a nickel-containing composition, a copper-containing composition and a combination thereof. 
     In another embodiment, the binder material can include a chemical agent configured to chemically react with a workpiece in contact with the abrasive article to facilitate a chemical removal process on the surface of the workpiece while the abrasive article is also conducting a mechanical removal process. Some suitable chemical agents can include oxides, carbides, nitrides, an oxidizer, pH modifier, surfactant, and a combination thereof. 
     The agglomerated particle of embodiments herein can include a particular content of abrasive particles, a particular content of binder material, and a particular content of porosity. For example, the agglomerated particle can include a greater content of abrasive particle than a content of binder material. Alternatively, the agglomerated particle can include a greater content of binder material than a content of abrasive particle. For example, in one embodiment, the agglomerated particle can include at least about 5 vol % abrasive particle for the total volume of the agglomerated particle. In other instances, the content of abrasive particles for the total volume of the agglomerated particle can be greater, such as at least about 10 vol %, such as at least about 20 vol %, at least about 30 vol %, at least about 40 vol %, at least about 50 vol %, at least about 60 vol %, at least about 70 vol %, at least about 80 vol %, or even at least about 90 vol %. Yet, in another non-limiting embodiment, the content of abrasive particles in an agglomerated particle for the total volume of the agglomerated particle can be not greater than about 95 vol %, such as not greater than about 90 vol %, not greater than about 80 vol %, not greater than about 70 vol %, not greater than about 60 vol %, not greater than about 50 vol %, not greater than about 40 vol %, not greater than about 30 vol %, not greater than about 20 vol %, or even not greater than about 10 vol %. It will be appreciated that the content of the abrasive particles in the agglomerated particle can be within a range between any of the above minimum and maximum percentages. 
     According to another aspect, the agglomerated particle can include at least about 5 vol % binder material for the total volume of the agglomerated particle. In other instances, the content of binder material for the total volume of the agglomerated particle can be greater, such as at least about 10 vol %, such as at least about 20 vol %, at least about 30 vol %, at least about 40 vol %, at least about 50 vol %, at least about 60 vol %, at least about 70 vol %, at least about 80 vol %, or even at least about 90 vol %. Yet, in another non-limiting embodiment, the content of binder material in an agglomerated particle for the total volume of the agglomerated particle can be not greater than about 95 vol %, such as not greater than about 90 vol %, not greater than about 80 vol %, not greater than about 70 vol %, not greater than about 60 vol %, not greater than about 50 vol %, not greater than about 40 vol %, not greater than about 30 vol %, not greater than about 20 vol %, or even not greater than about 10 vol %. It will be appreciated that the content of the binder material in the agglomerated particle can be within a range between any of the above minimum and maximum percentages. 
     In yet another aspect, the agglomerated particle can include a particular content of porosity. For example, the agglomerated particle can include at least about 1 vol % porosity for the total volume of the agglomerated particle. In other instances, the content of porosity for the total volume of the agglomerated particle can be greater, such as at least about 5 vol %, at least about 10 vol %, at least about 20 vol %, at least about 30 vol %, at least about 40 vol %, at least about 50 vol %, at least about 60 vol %, at least about 70 vol %, or even at least about 80 vol %. Yet, in another non-limiting embodiment, the content of porosity in an agglomerated particle for the total volume of the agglomerated particle can be not greater than about 90 vol %, not greater than about 80 vol %, not greater than about 70 vol %, not greater than about 60 vol %, not greater than about 50 vol %, not greater than about 40 vol %, not greater than about 30 vol %, not greater than about 20 vol %, or even not greater than about 10 vol %. It will be appreciated that the content of the porosity in the agglomerated particle can be within a range between any of the above minimum and maximum percentages. 
     The porosity within the agglomerated particle can be of various types. For example, the porosity can be closed porosity, generally defined by discrete pores that are spaced apart from each other within the volume of the agglomerated particle. In at least one embodiment, a majority of the porosity within the agglomerated particle can be closed porosity. Alternatively, the porosity can be open porosity, defining a network of interconnected channels extending through the volume of the agglomerated particle. In certain instances, a majority of the porosity can be open porosity. 
     The agglomerated particle can be sourced from a supplier. Alternatively, the agglomerated particle may be formed prior to the formation of the abrasive article. Suitable processes for forming the agglomerated particle can include screening, mixing, drying, solidifying, electroless plating, electrolyte plating, sintering, brazing, spraying, printing, and a combination thereof. 
     According to one particular embodiment, the agglomerated particle can be formed in-situ with the formation of the abrasive article. For example, the agglomerated particle may be formed while forming the first layer or while forming a bonding layer over the first layer. Suitable processes for forming the agglomerated particle in-situ with the abrasive article can include a deposition process. Particular deposition processes can include, but are not limited to, plating, electroplating, dipping, spraying, printing, coating, gravity coating, and a combination thereof. In at least one particular embodiment, the process of forming the agglomerated particle comprises simultaneously forming a bonding layer and the agglomerated particle via a plating process. 
     Still, according to another embodiment, any of the abrasive particles, including the first type or second type can be placed on the abrasive article during the formation of the bonding layer. The abrasive particles may be deposited on the first layer with the bonding layer via a deposition process. Some suitable exemplary deposition processes can include spraying, gravity coating, electroless plating, electrolyte plating, dipping, die coating, electrostatic coating, and a combination thereof, 
     According to at least one embodiment, the first type of abrasive particle can have a first particle coating. Notably, the first particle coating layer can overlie the exterior surface of the first type of abrasive particle, and more particularly, may be in direct contact with the exterior surface of the first type of abrasive particle. Suitable materials for use as the first particle coating layer can include a metal or metal alloy. In accordance with one particular embodiment, the first particle coating layer can include a transition metal element, such as titanium, vanadium, chromium, molybdenum, iron, cobalt, nickel, copper, silver, zinc, manganese, tantalum, tungsten, and a combination thereof. One certain first particle coating layer can include nickel, such as a nickel alloy, and even alloys having a majority content of nickel, as measured in weight percent as compared to other species present within the first particle coating layer. In more particular instances, the first particle coating layer can include a single metal species. For example, the first particle coating layer can consist essentially of nickel. The first particle film layer can be a plated layer, such that it may be an electrolyte plated layer and an electroless plated layer. 
     The first particle coating layer can be formed to overlie at least a portion of the exterior surface of the first type of abrasive particle. For example, the first particle coating layer may overly at least about 50% of the exterior surface area of the abrasive particle. In other embodiments, the coverage of the first particle coating layer can be greater, such as at least about 75%, at least about 80%, at least about 90%, at least about 95%, or essentially the entire exterior surface of the first type of abrasive particle. 
     The first particle coating layer may be formed to have a particular content relative to the amount of the first type of abrasive particle to facilitate processing. For example, the first particle coating layer can be at least about 5% of the total weight of each of the first type of abrasive particle. In other instances, the relative content of the first particle coating layer to the total weight of each of the first type of abrasive particle can be greater, such as at least about 10%, at least about 20%, at least about 30%, at least about 40%, at least about 50%, at least about 60%, at least about 70%, or even at least about 80%. Yet, in another non-limiting embodiment, the relative content of the first particle coating layer to the total weight of each of the first type of abrasive particle may be not greater than about 100%, such as not greater than about 90%, not greater than about 80%, not greater than about 70%, not greater than about 60%, not greater than about 50%, not greater than about 40%, not greater than about 30%, not greater than about 20%, or even not greater than about 10%. It will be appreciated that the relative content of the first particle coating layer to the total weight of each of the first type of abrasive particle can be within a range between any of the minimum and maximum percentages noted above. 
     According to one embodiment, the first particle coating layer can be formed to have a particular thickness suitable to facilitate processing. For example, the first particle coating layer can have an average thickness of not greater than about 5 microns, such as not greater than about 4 microns, not greater than about 3 microns, or even not greater than about 2 microns. Still, according to one non-limiting embodiment, the first particle coating layer can have an average thickness of at least about 0.01 microns, 0.05 microns, at least about 0.1 microns, or even at least about 0.2 microns. It will be appreciated that the average thickness of the first particle coating layer can be within a range between any of the minimum and maximum values noted above. 
     According to certain aspects herein, the first particle coating layer can be formed of a plurality of discrete film layers. For example, the first particle coating layer can include a first particle film layer overlying the first type of abrasive particle, and a second particle film layer different than the first particle film layer overlying the first particle film layer. The first particle film layer may be in direct contact with an exterior surface of the first type of abrasive particle and the second particle film layer may be in direct contact with the first particle film layer. 
     In at least one aspect, the second particle film layer overlies at least about 50% of an exterior surface area of the first particle film layer on the first type of abrasive particle. In other instances, the second particle film overlies a greater surface area, such as at least about 75%, at least about 90%, or even essentially the entire exterior surface area of the first particle film layer of the first type of abrasive particle. 
     The first particle film layer can include any of the materials noted herein for the first particle coating layer, including for example, a metal, a metal alloy, and a combination thereof. In some instances, the first particle film layer may include a transition metal element, and more particularly, a metal such as titanium, vanadium, chromium, molybdenum, iron, cobalt, nickel, copper, silver, zinc, manganese, tantalum, tungsten, and a combination thereof. The first particle film layer may include a majority content of nickel, such that in some instances, the first particle film layer consists essentially of nickel. In yet another embodiment, the first particle film layer may consist essentially of copper. 
     The second particle film layer can include any of the materials noted herein for the first particle coating layer, including for example, a metal, a metal alloy, metal matrix composites, and a combination thereof. The second particle film layer may include the same material as the first particle film layer. However, in at least one embodiment, the second particle film layer includes a different material, and notably, may be completely distinct in composition from the first particle film layer. In some instances, the second particle film layer may include a transition metal element, and more particularly, a metal such as lead, silver, copper, zinc, tin, titanium, molybdenum, chromium, iron, manganese, cobalt, niobium, tantalum, tungsten, palladium, platinum, gold, ruthenium, and a combination thereof. The second particle film layer may include a majority content of tin, such that in some instances, the second particle film layer consists essentially of tin. In yet another embodiment, the second particle film layer may include a metal alloy of tin. 
     The second particle film layer may include a low temperature metal alloy (LTMA) material. The LTMA material can have a melting point of not greater than about 450° C., such as not greater than about 400° C., not greater than about 375° C., not greater than about 350° C., not greater than about 300° C., or even not greater than about 250° C. Still, according to at least one non-limiting embodiment, the LTMA material can have a melting point of at least about 100° C., such as at least about 125° C., or even at least about 150° C. It will be appreciated that the melting point of the LTMA material can be within a range between any of the minimum and maximum values noted above. 
     The first particle film layer can have an average thickness that is different than the average thickness of the second particle film layer. For example, in some instances, the first particle film layer can have an average thickness that is greater than the average thickness of the second particle film layer. In yet another embodiment, the first particle film layer can have an average thickness less than an average thickness of the second particle film layer. Still, in at least one non-limiting embodiment, the first particle film layer can have an average thickness substantially equal to the average thickness of the second particle film layer. 
     The first particle film layer may be present in a particular relative amount compared to the total weight of each of the first type of abrasive particle. For example, the relative content of the first particle film layer to the total weight of each of the first type of abrasive particle can be at least about 5%, such as at least about 10%, at least about 20%, at least about 30%, at least about 40%, at least about 50%, at least about 60%, at least about 70%, or even at least about 80%. Yet, in another non-limiting embodiment, the relative content of the first particle film layer to the total weight of each of the first type of abrasive particle may be not greater than about 100%, such as not greater than about 90%, not greater than about 80%, not greater than about 70%, not greater than about 60%, not greater than about 50%, not greater than about 40%, not greater than about 30%, not greater than about 20%, or even not greater than about 10%. It will be appreciated that the relative content of the first particle film layer to the total weight of each of the first type of abrasive particle can be within a range between any of the minimum and maximum percentages noted above. 
     The second particle film layer may be present in a particular relative amount compared to the total weight of each of the first type of abrasive particle and the first particle film layer. For example, the relative content of the second particle film layer to the total weight of each of the first type of abrasive particle and the first particle film layer can be at least about 5%, such as at least about 10%, at least about 20%, at least about 30%, at least about 40%, at least about 50%, at least about 60%, at least about 70%, or even at least about 80%. Yet, in another non-limiting embodiment, the relative content of the second particle film layer to the total weight of each of the first type of abrasive particle and the first particle film layer may be not greater than about 200%, such as not greater than about 150%, not greater than about 120%, not greater than about 100%, not greater than about 80%, not greater than about 60%, not greater than about 50%, not greater than about 40%, not greater than about 30%, or even not greater than about 20%. It will be appreciated that the relative content of the second particle film layer to the total weight of each of the first type of abrasive particle and the first particle film layer can be within a range between any of the minimum and maximum percentages noted above. 
     According to one embodiment, the first particle film layer can be formed to have a particular thickness suitable to facilitate processing. For example, the first particle film layer can have an average thickness of not greater than about 5 microns, such as not greater than about 4 microns, not greater than about 3 microns, or even not greater than about 2 microns. Still, according to one non-limiting embodiment, the first particle film layer can have an average thickness of at least about 0.01 microns, 0.05 microns, at least about 0.1 microns, or even at least about 0.2 microns. It will be appreciated that the average thickness of the first particle film layer can be within a range between any of the minimum and maximum values noted above. 
     According to one embodiment, the second particle film layer can be formed to have a particular thickness suitable to facilitate processing. For example, the second particle film layer can have an average thickness of not greater than about 5 microns, such as not greater than about 4 microns, not greater than about 3 microns, or even not greater than about 2 microns. Still, according to one non-limiting embodiment, the second particle film layer can have an average thickness of at least about 0.05 microns, 0.1 microns, at least about 0.3 microns, or even at least about 0.5 microns. It will be appreciated that the average thickness of the second particle film layer can be within a range between any of the minimum and maximum values noted above. 
     In yet another aspect, the first particle film layer can be formed to have a particular thickness relative to the first average particle size of the first type of abrasive particle, suitable to facilitate processing. For example, the first particle film layer can have an average thickness of not greater than about 50% of the first average particle size. In other embodiments, the average thickness of the first particle film layer relative to the first average particle size can be less, such as not greater than about 45%, not greater than about 40%, not greater than about 35%, not greater than about 30%, not greater than about 25%, not greater than about 20%, not greater than about 15%, not greater than about 10%, or even not greater than about 5%. Still, in at least one non-limiting embodiment, the average thickness of the first particle film layer relative to the first average particle size can be at least about 1%, at least about 5%, at least about 10%, at least about 15%, at least about 20%, at least about 25%, at least about 30%, at least about 40%, or even at least about 45%. It will be appreciated that the average thickness of the first particle film layer relative to the first average particle size can be within a range between any of the minimum and maximum percentages noted above. 
     According to another embodiment, the second particle film layer can be formed to have a particular thickness relative to the first average particle size of the first type of abrasive particle, suitable to facilitate processing. For example, the second particle film layer can have an average thickness of not greater than about 50% of the first average particle size. In other embodiments, the average thickness of the second particle film layer relative to the first average particle size can be less, such as not greater than about 45%, not greater than about 40%, not greater than about 35%, not greater than about 30%, not greater than about 25%, not greater than about 20%, not greater than about 15%, not greater than about 10%, or even not greater than about 5%. Still, in at least one non-limiting embodiment, the average thickness of the second particle film layer relative to the first average particle size can be at least about 1%, at least about 5%, at least about 10%, at least about 15%, at least about 20%, at least about 25%, at least about 30%, at least about 40%, or even at least about 45%. It will be appreciated that the average thickness of the second particle film layer relative to the first average particle size can be within a range between any of the minimum and maximum percentages noted above. 
     It will further be appreciated that the second type of abrasive particle can include a second particle coating layer. The second particle coating layer can include any of the features of the first particle coating layer, including properties, features, and characteristics relative to the second type of abrasive particle. 
     After placing the abrasive particles (e.g., the first type of abrasive particles, the second type of abrasive particles, and any other types) on the first layer at step  104 , the process can continue at step  105  by treating the abrasive article to form fillets and make connection between abrasive particles and the substrate. Treating may include processes such as heating, curing, drying, melting, sintering, solidification and a combination thereof. In one particular embodiment, treating includes a thermal process, such as heating the first layer to a temperature sufficient to induce melting of the first layer, while avoiding excessive temperatures to limit damage to the abrasive particles and substrate. For example, treating can include heating the substrate, first layer, and abrasive particles to a temperature of not greater than about 450° C. Notably, the process of treating can be conducted at a treating temperature that is less, such as not greater than about 375° C., not greater than about 350° C., not greater than about 300° C., or even not greater than about 250° C. In other embodiments, the process of treating can include heating the first layer to a melting point of at least about 100° C., at least about 150° C., or even at least about 175° C. 
     It will be appreciated that the heating process can facilitate melting of materials within the first layer and additional layers comprising the flux material to bond the abrasive particles to the first layer and the substrate. The heating process can facilitate the formation of a particular bond between the abrasive particle and the first layer. Notably, in the context of coated abrasive particles, a metallic bonding region can be formed between the particle coating material (e.g., the first particle coating layer and second particle coating layer) of the abrasive particles and the first layer material. The metallic bonding region can be characterized by diffusion bond region having an interdiffusion between at least one chemical species of the first layer and at least one species of the particle coating layer overlying the abrasive particles, such that the metallic bonding region comprises a mixture of chemical species from the two component layers. 
     After forming the first layer and applying the additional layers for facilitate binding of the abrasive particles, the excess material of the additional layers can be removed. For example, according to an embodiment, a cleaning process may be utilized to remove the excess additional layers, such as residual flux material. According to one embodiment, the cleaning process may utilize one or a combination of water, acids, bases, surfactants, catalysts, solvents, and a combination thereof. In one particular embodiment, the cleaning process can be a staged process, starting with a rinse of the abrasive article using a generally neutral material, such as water or deionized water. The water may be room temperature or hot, having a temperature of at least about 40° C. After the rinsing operation the cleaning process may include an alkaline treatment, wherein the abrasive article is traversed through a bath having a particular alkalinity, which may include an alkaline material. The alkaline treatment may be conducted at room temperature, or alternatively, at elevated temperatures. For example, the bath of the alkaline treatment may have a temperature of at least about 40° C., such at least about 50° C., or even at least about 70° C., and not greater than about 200° C. The abrasive article may be rinsed after the alkaline treatment. 
     After the alkaline treatment, the abrasive article may undergo an activation treatment. The activation treatment may include traversing the abrasive article through a bath having a particular element or compound, including an acid, a catalyst, a solvent, a surfactant, and a combination thereof. In one particular embodiment, the activation treatment can include an acid, such as a strong acid, and more particularly hydrochloric acid, sulfuric acid, and a combination thereof. In some instances, the activation treatment can include a catalyst that may include a halide or halide-containing material. Some suitable examples of catalysts can include potassium hydrogen fluoride, ammonium bifluoride, sodium bifluoride, and the like. 
     The activation treatment may be conducted at room temperature, or alternatively, at elevated temperatures. For example, the bath of the activation treatment may have a temperature of at least about 40° C., but not greater than about 200° C. The abrasive article may be rinsed after the activation treatment. 
     According to one embodiment, after suitably cleaning the abrasive article, an optional process may be utilized to facilitate the formation of abrasive particles having exposed surfaces after complete formation of the abrasive article. For example, in one embodiment, an optional process of selectively removing at least a portion of the particle coating layer on the abrasive particles may be utilized. The selective removal process may be conducted such that the material of the particle coating layer is removed while other materials of the abrasive article, including for example, the first layer are less affected, or even essentially unaffected. According to a particular embodiment, the process of selectively removing comprises etching. Some suitable etching processes can include wet etching, dry etching, and a combination thereof. In certain instances, a particular etchant may be used that is configured to selectively remove the material of the particle coating layer of the abrasive particles and leaving the first layer intact. Some suitable etchants can include nitric acid, sulfuric acid, hydrochloride acid, organic acid, nitric salt, sulfuric salt, chloride salt, alkaline cyanide based solutions, and a combination thereof. 
     As described herein, the abrasive article can include a first type of abrasive particle and a second type of abrasive particle different than the first type of abrasive particle. In certain instances, the selective removal process can be conducted on only the first type of abrasive particle, only the second type of abrasive particle, or both the first type of abrasive particle and the second type of abrasive particle. Selective removal of the particle coating layer of either the first type or second type may be facilitated by the use of a first type of abrasive particle having a first particle coating layer different than the second particle coating layer of the second type of abrasive particle. 
     In yet another embodiment, the formation of abrasive particles having exposed surfaces (See, for example,  FIGS. 12A and 12B ) can be facilitated by the use of abrasive particles having a particle coating layer that is discontinuous. That is, the particle coating layer can overlie a fraction of the total exterior surface area, such that the particle coating layer has gaps or openings in the coating layer. Such particles may also facilitate the formation of abrasive particles having exposed surfaces without the necessarily utilizing a selective removal process. 
     After treating the first layer at step  105 , the process can continue at step  106 , by forming a bonding layer over the first layer and abrasive particles. Formation of the bonding layer can facilitate formation of an abrasive article having improved performance, including but not limited to, wear resistance and particle retention. Furthermore, the bonding layer can enhance abrasive particle retention for the abrasive article. In accordance with an embodiment, the process of forming the bonding layer can include deposition of the bonding layer on the external surface of the article defined by the abrasive particles and the first layer. In fact, the bonding layer can be bonded directly to the abrasive particles and the first layer. 
     Forming the bonding layer can include a deposition process. Some suitable deposition processes can include plating (electrolyte or electroless), spraying, dipping, printing, coating, and a combination thereof. In accordance with one particular embodiment, the bonding layer can be formed by a plating process. For at least one particular embodiment, the plating process can be an electrolyte plating process. In another embodiment, the plating process can include an electroless plating process. 
     The bonding layer can be formed such that it can directly contact at least a portion of the first layer, a portion of the first type of abrasive particle, a portion of the second type of abrasive particle, the particle coating layer on the first type of abrasive particle, the particle coating layer on the second type of abrasive particle, and a combination thereof. 
     The bonding layer can overlie a majority of an external surface of the substrate and an external surface of the first type of abrasive particle. Moreover, in certain instances, the bonding layer can overlie a majority of an external surface of the substrate and an external surface of the second type of abrasive particle. In certain embodiments, the bonding layer can be formed such that it overlies at least 90% of the exposed surfaces of the abrasive particles and first layer. In other embodiments, the coverage of the bonding layer can be greater, such that it overlies at least about 92%, at least about 95%, or even at least about 97% of the exposed surfaces of the abrasive particles and first layer. In one particular embodiment, the bonding layer can be formed such that it can overlie essentially all of the external surfaces of the first type of abrasive particle, the second type of abrasive particle, and the substrate, thus defining the exterior surface of the abrasive article. 
     Still, in an alternative embodiment, the bonding layer can be selectively placed, such that exposed regions can be formed on the abrasive article. Further description of a selectively formed bonding layer with exposed surfaces of diamond are provided herein. 
     The bonding layer can be made of a particular material, such as an organic material, inorganic material, and a combination thereof. Some suitable organic materials can include polymers such as a UV curable polymer, thermosets, thermoplastics, and a combination thereof. Some other suitable polymer materials can include urethanes, epoxies, polyimides, polyamides, acrylates, polyvinyls, and a combination thereof. 
     Suitable inorganic materials for use in the bonding layer can include metals, metal alloys, cements, ceramics, composites, and a combination thereof. In one particular instance, the bonding layer can be formed of a material having at least one transition metal element, and more particularly a metal alloy containing a transition metal element. Some suitable transition metal elements for use in the bonding layer can include lead, silver, copper, zinc, tin, titanium, molybdenum, chromium, iron, manganese, cobalt, niobium, tantalum, tungsten, palladium, platinum, gold, ruthenium, and a combination thereof. In certain instances, the bonding layer can include nickel, and may be a metal alloy comprising nickel, or even a nickel-based alloy. In still other embodiments, the bonding layer can consist essentially of nickel. 
     In accordance with one embodiment, the bonding layer can be made of a material, including for example, composite materials, having a hardness that is greater than a hardness of the first layer. For example, the bonding layer can have a Vickers hardness that is at least about 5% harder than a Vickers hardness of the first layer based on the absolute values of the equation ((Hb−Ht)/Hb)×100%, wherein Hb represents the hardness of the bonding layer and Ht represents the hardness of the first layer. In one embodiment, the bonding layer can be at least about 10% harder, such as at least about 20% harder, at least about 30% harder, at least about 40% harder, at least about 50% harder, at least about 75% harder, at least about 90% harder, or even at least about 99% harder than the hardness of the first layer. Yet, in another non-limiting embodiment, the bonding layer may be not greater than about 99% harder, such as not greater than about 90% harder, not greater than about 80% harder, not greater than about 70% harder, not greater than about 60% harder, not greater than about 50% harder, not greater than about 40% harder, not greater than about 30% harder, not greater than about 20% harder, not greater than about 10% harder than the hardness of the first layer. It will be appreciated that the difference between the hardness of the bonding layer and the first layer can be within a range between any of the above minimum and maximum percentages. 
     Additionally, the bonding layer can have a fracture toughness (K1c) as measured by indentation method, that is at least about 5% greater than an average fracture toughness of the first layer based on the absolute values of the equation ((Tb−Tt)/Tb)×100%, wherein Tb represents the fracture toughness of the bonding layer and Tt represents the fracture toughness of the first layer. In one embodiment, the bonding layer can have a fracture toughness of at least about 8% greater, such as at least about 10% greater, at least about 15% greater, at least about 20% greater, at least about 25% greater, at least about 30% greater, or even at least about 40% greater than the fracture toughness of the first layer. Yet, in another non-limiting embodiment, the fracture toughness of the bonding layer may be not greater than about 90% greater, such as not greater than about 80% greater, not greater than about 70% greater, not greater than about 60% greater, not greater than about 50% greater, not greater than about 40% greater, not greater than about 30% greater, not greater than about 20% greater, or even not greater than about 10% greater than the fracture toughness of the first layer. It will be appreciated that the difference between the fracture toughness of the bonding layer and the fracture toughness of the first layer can be within a range between any of the above minimum and maximum percentages. 
     Optionally, the bonding layer can include a filler material. The filler can be various materials suitable for enhancing performance properties of the finally-formed abrasive article. Some suitable filler materials can include abrasive particles, pore-formers such as hollow sphere, glass spheres, bubble alumina, natural materials such as shells and/or fibers, metal particles, and a combination thereof. 
     In one particular embodiment, the bonding layer can include a filler in the form of abrasive particles that may represent a third type of abrasive particle, which can be the same as or different from the first type of abrasive particle and the second type of abrasive particle. The abrasive particle filler can be significantly different than the first type and second type of abrasive particles, particularly with regard to size, such that in certain instances the abrasive particle filler can have an average particle size that is substantially less than the average particle size of the first type and second type of abrasive particles bonded to the first layer. For example, the abrasive particle filler can have an average grain size that is at least about 2 times less than the average particle size of the abrasive particles. In fact, the abrasive filler may have an average particle size that is even smaller, such as on the order of at least 3 times less, such as at least about 5 times less, at least about 10 times less, and particularly within a range between about 2 times and about 10 times less than the average particle size of the first type of abrasive particle, second type of abrasive particle, or both. 
     The abrasive grain filler within the bonding layer can be made from a material such as carbides, carbon-based materials (e.g. fullerenes), diamond, borides, nitrides, oxides, oxynitrides, oxyborides, and a combination thereof. In particular instances, the abrasive grain filler can be a superabrasive material such as diamond, cubic boron nitride, or a combination thereof. 
     After forming the bonding layer at step  106 , the process may optionally continue at step  107 , with forming a coating layer overlying the bonding layer. In particular, the coating layer may be overlying the substrate, overlying the optional barrier layer, overlying the tacking film, overlying at least a portion of the abrasive particles (e.g., first type and/or second type of abrasive particles), and overlying at least a portion of the bonding layer, and a combination thereof. In at least one instance, the coating layer can be formed such that it is in direct contact with at least a portion of the bonding layer, at least a portion of the abrasive particles (e.g., first type and/or second type of abrasive particles), and a combination thereof. 
     Forming of the coating layer can include a deposition process. Some suitable deposition processes can include plating (electrolyte or electroless), spraying, dipping, printing, coating, and a combination thereof. In accordance with one particular embodiment, the coating layer can be formed by a plating process, and more particularly, can be electroplated directly to an external surface of the first type of abrasive particle and the second type of abrasive particle. In another embodiment, the coating layer can be formed via a dip coating process. According to yet another embodiment, the coating layer can be formed via spraying process. 
     The coating layer can overlie a portion of an exterior surface area of the bonding layer, abrasive particles, and a combination thereof. For example, the coating layer can overlie at least about 25% of an exterior surface area of the abrasive particle and the bonding layer. In still another design herein, the bonding layer can overlie a majority of an external surface of the bonding layer. Moreover, in certain instances, the coating layer can overlie a majority of an external surface of the bonding layer and abrasive particles. In certain embodiments, the coating layer can be formed such that it overlies at least 90% of the exposed surfaces of the abrasive particles and bonding layer. In other embodiments, the coverage of the coating layer can be greater, such that it overlies at least about 92%, at least about 95%, or even at least about 97% of the exposed surfaces of the abrasive particles and bonding layer. In one particular embodiment, the coating layer can be formed such that it can overlie essentially all of the external surfaces of the first type of abrasive particle, the second type of abrasive particle, and the bonding layer, thus defining the exterior surface of the abrasive article. 
     The coating layer can include an organic material, an inorganic material, and a combination thereof. According to one aspect, the coating layer can include a material such as a metal, metal alloy, cermet, ceramic, organic, glass, and a combination thereof. More particularly, the coating layer can include a transition metal element, including for example, a metal from the group of titanium, vanadium, chromium, molybdenum, iron, cobalt, nickel, copper, silver, zinc, manganese, tantalum, tungsten, and a combination thereof. For certain embodiments, the coating layer can include a majority content of nickel, and in fact, may consist essentially of nickel. Alternatively, the coating layer can include a thermoset, a thermoplastic, and a combination thereof. In one instance, the coating layer includes a resin material and may be essentially free of a solvent. 
     In one particular embodiment, the coating layer can include a filler material, which may be a particulate material. For certain embodiments, the coating layer filler material can be in the form of abrasive particles, which may represent a third type of abrasive particle that can be the same as or different from the first type of abrasive particle and the second type of abrasive particle. Certain suitable types of abrasive particles for use as the coating layer filler material can include carbides, carbon-based materials (e.g., diamond), borides, nitrides, oxides, and a combination thereof. Some alternative filler materials can include pore-formers such as hollow sphere, glass spheres, bubble alumina, natural materials such as shells and/or fibers, metal particles, and a combination thereof. 
     The coating filler material be significantly different than the first type and second type of abrasive particles, particularly with regard to size, such that in certain instances the abrasive particle filler material can have an average particle size that is substantially less than the average particle size of the first type and second type of abrasive particles bonded to the first layer. For example, the coating layer filler material can have an average particle size that is at least about 2 times less than the average particle size of the abrasive particles. In fact, the coating layer filler material may have an average particle size that is even smaller, such as on the order of at least 3 times less, such as at least about 5 times less, at least about 10 times less, and particularly within a range between about 2 times and about 10 times less than the average particle size of the first type of abrasive particle, second type of abrasive particle, or both. 
       FIG. 2A  includes a cross-sectional illustration of a portion of an abrasive article in accordance with an embodiment.  FIG. 2B  includes a cross-sectional illustration of a portion of an abrasive article including an optional barrier layer in accordance with an embodiment. As illustrated, the abrasive article  200  can include a substrate  201 , which is in the form of an elongated body, such as a wire. As further illustrated, the abrasive article can include a first layer  202  disposed over the entire external surface of the substrate  201 . Furthermore, the abrasive article  200  can include abrasive particles  203  including a coating layer  204  overlying the abrasive particles  203 . The abrasive particles  203  can be bonded to the first layer  202 . In particular, the abrasive particles  203  can be bonded to the first layer  202  at the interface  206 , wherein a metallic bonding region can be formed as described herein. 
     The abrasive article  200  can include a particle coating layer  204  overlying the external surfaces of the abrasive particles  203 . Notably, the coating layer  204  can be in direct contact with the first layer  202 . As described herein, the abrasive particles  203 , and more particularly, the particle coating layer  204  of the abrasive particles  203 , can form a metallic bonding region at the interface between the coating layer  204  and the first layer  202 . 
     According to one embodiment, the first layer  202  can have a particular average thickness as compared to the average particle size of the abrasive particles  203 . It will be appreciated that reference herein to an average particle size can include reference to the first average particle size of the first type of abrasive particle, the second average particle size of the second type of abrasive particle, or a total average particle size, which is an average of the first average particle size and the second average particle size. Furthermore, to the extent that the abrasive article includes a third type of abrasive particle, the foregoing also applies. 
     The first layer  202  can have an average thickness that is not greater than about 80% of the average particle size of the abrasive particles  203  (i.e., the first average particle size of the first type of abrasive particles, the second average particle size of the second type of abrasive particles, or the total average particle size). The relative average thickness of the first layer to the average particle size can be calculated by the absolute value of the equation ((Tp−Tt)/Tp)×100%, wherein Tp represents the average particle size and Tt represents the average thickness of the bonding layer. In other abrasive articles, the first layer  202  can have an average thickness of not greater than about 70%, such as not greater than about 60%, not greater than about 50%, not greater than about 40%, not greater than about 30%, not greater than about 25%, or even not greater than about 20% of the average particle size of the abrasive particles  203 . Still, in certain instances the average thickness of the first layer  202  can be at least about 2%, such as at least about 3%, such as at least about 5%, at least about 8%, at least about 10%, at least about 11%, at least about 12%, or even at least about 13% of the average particle size of the abrasive particles  203 . It will be appreciated that the first layer  202  can have an average thickness within a range between any of the minimum and maximum percentages noted above. 
     In alternative terms, according to certain abrasive articles, the first layer  202  can have an average thickness that is not greater than about 25 microns. In still other embodiments, the first layer  202  can have an average thickness that is not greater than about 20 microns, such as not greater than about 10 microns, not greater than about 8 microns, or even not greater than about 5 microns. In accordance with an embodiment, the first layer  202  can have an average thickness that is at least about 0.1 microns, such as at least about 0.2 microns, at least about 0.5 micron, or even at least about 1 micron. It will be appreciated that the first layer  202  can have an average thickness within a range between any of the minimum and maximum values noted above. 
     In particular instances, for nickel coated abrasive particles having an average particle size of less than about 20 microns, the average thickness of the first layer can be at least about 0.5 micron. Further, the average thickness can be at least about 1.0 microns, or at least about 1.5 microns. The average thickness can be limited, however, such as not greater than about 5.0 microns, not greater than about 4.5 microns, not greater than 4.0 microns, not greater than 3.5 microns, or not greater than 3.0 microns. For abrasive particles having an average particle size within a range of 10 and 20 microns, the first layer  202  can have an average thickness within a range between and including any of the minimum and maximum thickness values noted above. 
     Alternatively, for nickel coated abrasive particles having an average particle size of at least about 20 microns, and more particularly within a range of about 40-60 microns, the average thickness of the first layer can be at least about 1 micron. Further, the average thickness can be at least about 1.25 microns, at least about 1.5 microns, at least about 1.75 microns, at least about 2.0 microns, at least about 2.25 microns, at least about 2.5 microns, or at least about 3.0 microns. The average thickness can be limited, however, such as not greater than about 8.0 microns, not greater than about 7.5 microns, not greater than 7.0 microns, not greater than 6.5 microns, not greater than 6.0 microns, not greater than 5.5 microns, not greater than 5.0 microns, not greater than 4.5 microns, or not greater than 4.0 microns. For abrasive particles having an average particle size within a range of 40 and 60 microns, the first layer  202  can have an average thickness within a range between and including any of the minimum and maximum values noted above. 
     As further illustrated, the bonding layer  205  can be directly overlying and directly bonded to the abrasive particles  203  and the first layer  202 . According to an embodiment, the bonding layer  205  can be formed to have a particular thickness. For example, the bonding layer  205  can have an average thickness of at least about 5% of the average particle size of the abrasive particles  203  (i.e., the first average particle size of the first type of abrasive particles, the second average particle size of the second type of abrasive particles, or the total average particle size). The relative average thickness of the bonding layer to the average particle size can be calculated by the absolute value of the equation ((Tp−Tb)/Tp)×100%, wherein Tp represents the average particle size and Tb represents the average thickness of the bonding layer. In other embodiments, the average thickness of the bonding layer  205  can be greater, such as at least about 10%, at least about 15%, at least about 20%, at least about 30%, or even at least about 40%. Still, the average thickness of the bonding layer  205  can be limited, such that it is not greater than about 100%, not greater than about 90%, not greater than about 85%, or even not greater than about 80% of the average particle size of the abrasive particles  203 . It will be appreciated that the bonding layer  205  can have an average thickness within a range between any of the minimum and maximum percentages noted above. 
     In more particular instances, the bonding layer  205  can be formed to have an average thickness that is at least 1 micron. For other abrasive articles, the bonding layer  205  can have a greater average thickness, such as at least about 2 microns, at least about 3 microns, at least about 4 microns, at least about 5 microns, at least about 7 microns, or even at least about 10 microns. Particular abrasive articles can have a bonding layer  205  having an average thickness that is not greater than about 60 microns, such as not greater than about 50 microns, such as not greater than about 40 microns, not greater than about 30 microns, or not greater than about 20 microns. It will be appreciated that the bonding layer  205  can have an average thickness within a range between any of the minimum and maximum values noted above. 
     The abrasive particles  203  can be positioned in a particular manner relative to other component layers of the abrasive article. For example, in at least one embodiment, a majority of the first type of abrasive particle can be spaced apart from the substrate. Moreover, in certain instances, a majority of the first type of abrasive particle can be spaced apart from a barrier layer  230  of the substrate  201  (See,  FIG. 2B  which includes an alternative illustration of a portion of an abrasive article according to an embodiment including a barrier layer). More particularly, the abrasive article may be formed such that essentially all of the first type of abrasive particle is spaced apart from the barrier layer. Additionally, it will be appreciated that a majority of the second type of abrasive particle can be spaced apart from the substrate  201  and the barrier layer  203 . In fact, in certain instances essentially all of the second type of abrasive particle is spaced apart from the barrier layer  203 . 
     The abrasive article  250  illustrated in  FIG. 2B  includes an optional barrier layer, in accordance with an embodiment. As illustrated, the barrier layer  230  can include an inner layer  231  in direct contact with the substrate  201  and an outer layer  232  overlying the inner layer  231 , and in particular, in direct contact with the inner layer  231 . 
       FIG. 2C  includes a cross-sectional illustration of a portion of an abrasive article including an optional coating layer in accordance with an embodiment. As illustrated, the abrasive article  260  can include a coating layer  235  overlying the bonding layer  205 . According to a particular embodiment, the coating layer  235  can have an average thickness of at least about 5% of an average particle size of the abrasive particles  203  (i.e., the first average particle size of the first type of abrasive particles, the second average particle size of the second type of abrasive particles, or the total average particle size). The relative average thickness of the coating layer to the average particle size can be calculated by the absolute value of the equation ((Tp−Tc)/Tp)×100%, wherein Tp represents the average particle size and Tc represents the average thickness of the coating layer. In other embodiments, the average thickness of the coating layer  235  can be greater, such as at least about 8%, at least about 10%, at least about 15%, or even at least about 20%. Still, in another non-limiting embodiment, the average thickness of the coating layer  235  can be limited, such that it is not greater than about 50%, not greater than about 40%, not greater than about 30%, or even not greater than about 20% of the average particle size of the abrasive particles  203 . It will be appreciated that the coating layer  235  can have an average thickness within a range between any of the minimum and maximum percentages noted above. 
     The coating layer  235  can have a particular average thickness relative to the average thickness of the bonding layer  205 . For example, the average thickness of the coating layer  235  can be less than an average thickness of the bonding layer  205 . In one particular embodiment, the average thickness of the coating layer  235  and the average thickness of the bonding layer can define a ratio (Tc:Tb) of at least about 1:2, at least about 1:3, or even at least about 1:4. Still, in at least one embodiment, the ratio can be not greater than about 1:20, such as not greater than about 1:15, or even not greater than about 1:10. It will be appreciated that the ratio can be within a range between any of the upper and lower limits noted above. 
     According to a particular aspect, the coating layer  235  may be formed to have an average thickness of not greater than about 15 microns, such as not greater than about 10 microns, not greater than about 8 microns, or even not greater than about 5 microns. Still, the average thickness of the coating layer  235  may be at least about 0.1 microns, such as at least about 0.2 microns, or even at least about 0.5 microns. The coating layer may have an average thickness within a range between any of the minimum and maximum values noted above. 
       FIG. 2D  includes a cross-sectional illustration of a portion of an abrasive article including a first type of abrasive particle and a second type of abrasive particle in accordance with an embodiment. As illustrated, the abrasive article  280  can include a first type of abrasive particle  283  coupled to the substrate  201  and a second type of abrasive particle  284  different than the first type of abrasive particle  283  coupled to the substrate  201 . The first type of abrasive particle  283  can include any features described in embodiments herein, notably including an agglomerated particle. The second type of abrasive particle  284  can include any features described in embodiments herein, including for example, an unagglomerated particle. According to at least one embodiment, the first type of abrasive particle  283  can be different from the second type of abrasive particle  284  based on at least one particle characteristic of the group consisting of hardness, friability, toughness, particle shape, crystalline structure, average particle size, composition, particle coating, grit size distribution, and a combination thereof. 
     Notably, the first type of abrasive particle  283  can be an agglomerated particle.  FIG. 9  includes an illustration of an exemplary agglomerated particle according to an embodiment. The agglomerated particle  900  can include abrasive particles  901  contained within a binder material  903 . Furthermore, as illustrated, the agglomerated particle can include a content of porosity defined by pores  905 . The pores may be present within the binder material  903  between the abrasive particles  901 , and in particular instances, essentially all of the porosity of the agglomerated particles can be present within the binder material  903 . 
     According to one particular aspect, the abrasive article can be formed to have a particular abrasive particle concentration. For example, in one embodiment, the average particle size (i.e., the first average particle size or the second average particle size or the total average particle size) can be less than about 20 microns, and the abrasive article can have an abrasive particle concentration of at least about 5 particles per mm of substrate. It will be appreciated that reference to the particles per length is reference to the first type of abrasive particle, the second type of abrasive particle, or the total content of all types of abrasive particles of the article. In yet another embodiment, the abrasive particle concentration can be at least about 20 particles per mm of substrate, at least about 30 particles per mm of substrate, at least about 60 particles per mm of substrate, at least about 100 particles per mm of substrate, at least about 200 particles per mm of substrate, at least about 250 particles per mm of substrate, or even at least about 300 particles per mm of substrate. In another aspect, the abrasive particle concentration may be no greater than about 800 particles per mm of substrate, such as no greater than about 700 particles per mm of substrate, no greater than about 650 particles per mm of substrate, or no greater than about 600 particles per mm of substrate. It will be appreciated that the abrasive particle concentration can be within a range between any of these above minimum and maximum values. 
     According to one particular aspect, the abrasive article can be formed to have a particular abrasive particle concentration. For example, in one embodiment, the average particle size (i.e., the first average particle size or the second average particle size or the total average particle size) can be at least about 20 microns, and the abrasive article can have an abrasive particle concentration of at least about 10 particles per mm of substrate, such as, at least about 7 particles per mm of substrate or even at least about 5 particles per mm of substrate. It will be appreciated that reference to the particles per length is reference to the first type of abrasive particle, the second type of abrasive particle, or the total content of all types of abrasive particles of the article. In yet another embodiment, the abrasive particle concentration can be at least about 20 particles per mm of substrate, at least about 30 particles per mm of substrate, at least about 60 particles per mm of substrate, at least about 80 particles per mm of substrate, or even at least about 100 particles per mm of substrate. In another aspect, the abrasive particle concentration may be no greater than about 200 particles per mm of substrate, such as no greater than about 175 particles per mm of substrate, no greater than about 150 particles per mm of substrate, or no greater than about 100 particles per mm of substrate. It will be appreciated that the abrasive particle concentration can be within a range between any of these above minimum and maximum values. 
     In another aspect, the abrasive article can be formed to have a particular abrasive particle concentration, measured as carats per kilometer length of the substrate. For example, in one embodiment, the average particle size (i.e., the first average particle size or the second average particle size or the total average particle size) can be less than about 20 microns, and the abrasive article can have an abrasive particle concentration of at least about 0.5 carats per kilometer of the substrate. It will be appreciated that reference to the particles per length is reference to the first type of abrasive particle, the second type of abrasive particle, or the total content of all types of abrasive particles of the article. In another embodiment, the abrasive particle concentration can be at least about 1.0 carats per kilometer of substrate, such as at least about 1.5 carats per kilometer of substrate, at least about 2.0 carats per kilometer of substrate, at least about 3.0 carats per kilometer of substrate, at least about 4.0 carats per kilometer of substrate, or even at least about 5.0 carats per kilometer of substrate. Still, in one non-limiting embodiment, the abrasive particle concentration may be not be greater than 15.0 carats per kilometer of substrate, not greater than 14.0 carats per kilometer of substrate, not greater than 13.0 carats per kilometer of substrate, not greater than 12.0 carats per kilometer of substrate, not greater than 11.0 carats per kilometer of substrate, or even not greater than 10.0 carats per kilometer of substrate. The abrasive particle concentration can be within a range between any of the above minimum and maximum values. 
     For yet another aspect, the abrasive article can be formed to have a particular abrasive particle concentration, wherein the average particle size (i.e., the first average particle size or the second average particle size or the total average particle size) can be at least about 20 microns. In such instances, the abrasive article can have an abrasive particle concentration of at least about 0.5 carats per kilometer of the substrate. It will be appreciated that reference to the particles per length is reference to the first type of abrasive particle, the second type of abrasive particle, or the total content of all types of abrasive particles of the article. In another embodiment, the abrasive particle concentration can be at least about 3 carats per kilometer of substrate, such as at least about 5 carats per kilometer of substrate, at least about 10 carats per kilometer of substrate, at least about 15 carats per kilometer of substrate, at least about 20 carats per kilometer of substrate, or even at least about 50 carats per kilometer of substrate. Still, in one non-limiting embodiment, the abrasive particle concentration may be not be greater than 200 carats per kilometer of substrate, not greater than 150 carats per kilometer of substrate, not greater than 125 carats per kilometer of substrate, or even not greater than 100 carats per kilometer of substrate. The abrasive particle concentration can be within a range between any of the above minimum and maximum values. 
       FIG. 10A  includes a longitudinal side illustration of a portion of an abrasive article according to an embodiment.  FIG. 10B  includes a cross-sectional illustration of a portion of the abrasive article of  FIG. 10A  according to an embodiment. In particular, the abrasive article  1000  can include a first type of abrasive particle  283  that can define a first layer of abrasive particles  1001 . As illustrated, and according to an embodiment, the first layer of abrasive particles  1001  can define a first pattern  1003  on the surface of the article  1000 . The first pattern  1003  can be defined by a relative arrangement of at least a portion (e.g., a group) of the first type of abrasive particle  283  relative to each other. The arrangement or ordered array of the group of first type of abrasive particles may be described relative to at least one dimensional component of the substrate  201 . Dimensional components can include a radial component, wherein a group of the first type of abrasive particle  283  can be arranged in an ordered array relative to a radial dimension  1081  that can define a radius or diameter (or thickness if not circular) of the substrate  201 . Another dimensional component can include an axial component, wherein a group of the first type of abrasive particle  283  can be arranged in an ordered array relative to a longitudinal dimension  1080  that can define a length (or thickness if not circular) of the substrate  201 . Yet another dimensional component can include a circumferential component, wherein a group of the first type of abrasive particle  283  can be arranged in an ordered array relative to a circumferential dimension  1082  that can define a circumference (or periphery if not circular) of the substrate  201 . 
     According to at least one embodiment, the first pattern  1003  can be defined by a repeating axial component. As illustrated in  FIG. 10A , the first pattern  1003  includes an ordered array of a group of the first type of abrasive particle  283  overlying the surface of the substrate  201  that defines a repeating axial component, wherein each of the first type of abrasive particle  283  within the group can have an ordered and predetermined axial position relative to each other. Stated alternatively, each of the first type of abrasive particle within the group defining the first pattern  1003  are longitudinally spaced apart from each other in an ordered manner thus defining a repeating axial component of the first pattern  1003 . While the foregoing has described the first pattern  1003  as defined by a group of the first type of abrasive particle, it will be appreciated that a pattern can be defined by a combination of different types of abrasive particles, such as an ordered array of the first and second types of abrasive particles. 
     As further illustrated in  FIG. 10A , the abrasive article  1000  can include a second type of abrasive particle  284  that can define a second layer of abrasive particles  1002 . The second layer of abrasive particles  1002  can be different than the first layer of abrasive particles  1001 . In particular designs, the first layer of abrasive particles  1001  can define a first radial position on the substrate  201  and the second layer of abrasive particles  1002  can define a second radial position on the substrate  201  that is different than the first radial position of the first layer of abrasive particles  1001 . Moreover, according to one embodiment, the first radial position of the first layer of abrasive particles  1001  and the second radial position defined by the second layer of abrasive particles  1002  can be radially spaced apart from each other relative to the radial dimension  1081 . 
     In yet another embodiment, the first layer of abrasive particles  1001  can define a first axial position and the second layer of abrasive particles  1002  can define a second axial position spaced apart from the first axial position relative to the longitudinal dimension  1080 . According to another embodiment, the first layer of abrasive particles  1001  can define a first circumferential position and the second layer of abrasive particles  1002  can define a second circumferential position spaced apart from the first circumferential position relative to the circumferential dimension  1082 . 
     In at least one embodiment, the abrasive article  1000  can include a first type of abrasive particle  283  that can define a first layer of abrasive particles  1001 , wherein each of the first type of abrasive particle  283  are substantially uniformly dispersed relative to each other on the surface of the abrasive article. Furthermore, as illustrated, the abrasive article  1000  can include a second type of abrasive particle  284  that can define a second layer of abrasive particles  100 , wherein each abrasive particle of the second type of abrasive particle  284  is substantially uniformly dispersed relative to the other abrasive particles on the surface of the abrasive article. 
     As illustrated, and according to an embodiment, the first layer of abrasive particles  1001  can be associated with a first pattern  1003  on the surface of the article  1000  and the second layer of abrasive particles  1002  can be associated with a second pattern  1004  on the surface of the article  1000 . Notably, in at least one embodiment, the first pattern  1002  and the second pattern  1004  are different relative to each other. According to one embodiment, the first pattern  1002  and second pattern  1004  can be separated from each other by a channel  1009 . Moreover, depending upon the method of forming, the first pattern  1002  may be associated with a first pattern of a first layer material relative to the surface of the substrate  201  (not shown) or a first pattern of the bonding layer material relative to the surface of the substrate  201  (not shown). Additionally or alternatively, the second pattern  1004  can be associated with a second pattern of a first layer material relative to the surface of the substrate  201  (not shown). The second pattern of the first layer may be different than the first pattern of the first layer. Still, in certain instances, the second pattern of the first layer can be the same as the first pattern of the first layer. According to one embodiment, the second pattern  1004  can be associated with a second pattern of the bonding layer relative to the surface of the substrate  201  (not shown), which may be different than the first pattern of the bonding layer. Still, in at least one embodiment, the second pattern of the bonding layer may be the same as the first pattern of the bonding layer. The first pattern of the first layer can be different than the second pattern of the first layer by at least a radial component, an axial component, a circumferential component, and a combination thereof. Moreover, the first pattern of the bonding layer can be different than the second pattern of the bonding layer by at least a radial component, an axial component, a circumferential component, and a combination thereof. 
     As illustrated in  FIG. 10A , the first pattern  1003  can be defined by a two-dimensional shape, such as a polygonal two-dimensional shape, such as a rectangle. Likewise, the second pattern  1004  can be defined by a two-dimensional shape, such as a polygonal two-dimensional shape, such as a rectangle. It will be appreciated that other two-dimensional shapes may be employed. 
     According to one particular embodiment, the second pattern  1004  can include an ordered array of a group of the second type of abrasive particle  284  overlying the surface of the substrate  201  that defines a repeating axial component, wherein each of the second type of abrasive particle  284  within the group can have an ordered and predetermined axial position relative to each other. For example, each of the second type of abrasive particle  284  within the group defining the second pattern  1004  can be longitudinally spaced apart from each other in an ordered manner thus defining a repeating axial component of the second pattern  1004 . While the foregoing has described the second pattern  1004  as defined by a group of the second type of abrasive particle, it will be appreciated that any pattern herein can be defined by a combination of different types of abrasive particles, such as an ordered array of the first and second types of abrasive particles. 
     As further illustrated in  FIG. 10A , the abrasive article  1000  can have a third pattern  1005  that can include an ordered array of a group of the first type of abrasive particle  283  and the second type of abrasive particle  284  overlying the surface of the substrate  201  that defines a repeating radial component. Each of the first type of abrasive particle  283  and second type of abrasive particle  284  within the group can have an ordered and predetermined radial position relative to each other. That is, for example, each of the first type of abrasive particle  283  and second type of abrasive particle  284  within the group defining the third pattern  1005  are radially spaced apart from each other in an ordered manner thus defining a repeating radial component of the third pattern  1005 . 
     In addition to the repeating radial component, the third pattern  1005  can include an ordered array of a group of the first type of abrasive particle  283  and the second type of abrasive particle  284  overlying the surface of the substrate  201  that defines a repeating circumferential component. As illustrated in  FIGS. 10A and 10B , the third pattern  1005  can be defined by each of the first type of abrasive particle  283  and second type of abrasive particle  284  within the group having an ordered and predetermined circumferential position relative to each other. That is, for example, each of the first type of abrasive particle  283  and second type of abrasive particle  284  within the group defining the third pattern  1005  are circumferentially spaced apart from each other in an ordered manner thus defining a repeating circumferential component of the third pattern  1005 . 
       FIG. 10C  includes a longitudinal side illustration of a portion of an abrasive article according to an embodiment. In particular, the abrasive article  1020  can include a first type of abrasive particle  283  that can define a first layer of abrasive particles  1021 . Notably, the first layer of abrasive particles  1021  can be arranged relative to each other to have a repeating axial component, repeating radial component, and repeating circumferential component. In accordance with one particular embodiment, the first layer of abrasive particles  1021  can define a first helical path extending around the substrate  201  and defined by a plurality of turns that can be axially spaced apart from each other. According to one embodiment, a single turn includes an extension of the first layer of abrasive particles  1021  around the circumference of the article for 360 degrees. The first helical path may be continuous, or alternatively, may be defined by an axial gap, a radial gap, a circumferential gap, and a combination thereof. 
     Moreover, the abrasive article  1020  can include a second type of abrasive particle  284  that can define a second layer of abrasive particles  1022 . Notably, the second layer of abrasive particles  1022  can be arranged relative to each other to have a repeating axial component, repeating radial component, and repeating circumferential component. In accordance with one particular embodiment, the second layer of abrasive particles  1022  can define a second helical path extending around the substrate  201 . The second helical path can be defined by a plurality of turns, wherein the turns can be axially spaced apart from each other, and wherein a single turn includes an extension of the second layer of abrasive particles  1022  around the circumference of the article for 360 degrees. The second helical path may be continuous, or alternatively, may be interrupted, wherein the second helical path can have an axial gap, a radial gap, a circumferential gap, and a combination thereof. 
     As illustrated, and according to a particular embodiment, the first layer of abrasive particles  1021  and second layer of abrasive particles  1022  can define an intertwined helical path, wherein the first layer of abrasive particles  1021  and second layer of abrasive particles  1022  alternate in the longitudinal dimension  1080 . It will be appreciated that a single helical path can be defined by a combination of the first type of abrasive particle and the second type of abrasive particle. 
     According to a particular embodiment, a lubricious material may be incorporated into the abrasive article to facilitate improved performance.  FIGS. 11A-11B  include illustrations of various abrasive articles having different deployments of a lubricious material according to embodiments herein. In at least one embodiment, the abrasive article can include a lubricious material overlying the substrate. In another instance, the lubricious material can be overlying the first layer. Alternatively, the lubricious material may be in direct contact with the first layer, and more particularly, may be contained within the first layer. For one design of an embodiment, the lubricious material can be overlying the abrasive particles, and even may be in direct contact with the abrasive particles. In still another embodiment, the lubricious material can be overlying the bonding layer, may be at the bonding layer, and in more particular instance, in direct contact with the bonding layer. According to one embodiment, the lubricious material can be contained within the bonding layer. Yet, in one alternative embodiment, the lubricious material can be overlying a coating layer, and more particularly, can be in direct contact with the coating layer, and even more particularly, can be contained within the coating layer. The lubricious material may be formed on the exterior of the abrasive article, such that it is configured to make contact with a workpiece. 
     The lubricious material may define at least a portion of the exterior surface of the abrasive article. Notably, the lubricious material can be in the form of a continuous coating, such as the lubricious material  1103  illustrated in  FIG. 11A  of the abrasive article  1100 . In such instances, the lubricious material can overlie a majority of the surface of the abrasive article  1100  and define a majority of the exterior surface of the abrasive article  1100 . According to one design of an embodiment, the lubricious material can define essentially the entire exterior surface of the abrasive article  1100 . 
     According to another embodiment, the lubricious material may define a non-continuous layer, wherein the lubricious material overlies the substrate and defines a fraction of the exterior surface of the abrasive article. The non-continuous layer may be defined by a plurality of gaps extending between portions of the lubricious material, wherein the gaps define regions absent the lubricious material. 
     According to one embodiment, the lubricious material can be in the form of discrete particles comprising a lubricious material. The discrete particles including the lubricious material may consist essentially of the lubricious material. More particularly, the discrete particles can be disposed at various places within the abrasive article, including but not limited to, in direct contact with the bonding layer, at least partially contained within the bonding layer, contained entirely within the bonding layer, at least partially contained within the coating layer, in direct contact with a coating layer and a combination thereof. For example, as illustrated in  FIG. 11B , the lubricious material  1103  is present as discrete particles contained in the bonding layer  205 . 
     For at least one embodiment, the lubricious material can be an organic material, an inorganic material, a natural material, a synthetic material, and a combination thereof. In one particular instance, the lubricious material can include a polymer, such as a fluoropolymer. One particularly suitable polymer material can include polytetrafluoroethylene (PTFE). In at least one embodiment, the lubricious material can consist essentially of PTFE. 
     Various methods of providing the lubricious material to the abrasive article may be utilized. For example, the process of providing the lubricious material may be conducted via a depositing process. Exemplary deposition processes can include spraying, printing, plating, coating, gravity coating, dipping, die coating, electrostatic coating, and a combination thereof. 
     Additionally, the process of providing the lubricious material may be conducted at different times during processing. For example, providing the lubricious material can be conducted simultaneously with forming the first layer. Alternatively, providing the lubricious material can be conducted simultaneously with providing the abrasive particles. In yet another embodiment, providing the lubricious material can be completed simultaneously with providing the bonding layer. Moreover, in one optional process, providing the lubricious material can be conducted simultaneously with providing a coating layer overlying the bonding layer. 
     Still, the process of providing the lubricious material can be conducted after completing certain processes. For example, providing the lubricious material can be conducted after forming the first layer, after providing the abrasive particles, after providing the bonding layer, or even after providing a coating layer. 
     Alternatively, it may be suitable to provide the lubricious material prior to forming certain layers. For example, providing the lubricious material can be conducted before forming the first layer, before providing the abrasive particles, before providing the bonding layer, or even before providing a coating layer. 
     Certain articles according to embodiments herein can be processed according to a particular method to facilitate the formation of abrasive particles having an exposed surface.  FIG. 12A  includes an illustration of an abrasive article including an abrasive particle having an exposed surface. As illustrated in  FIG. 12A , the abrasive article can be formed such that an abrasive particle  203  (e.g., first type or second type of abrasive particle) can have an exposed surface  1201 . According to an embodiment, the abrasive particle  203  can have a particle coating  1205  overlying a surface of the abrasive particle  203 , and preferentially disposed proximate to a lower surface  1204  of the abrasive particle  203 . In particular, the particle coating layer  1205  can be a non-continuous coating that is preferentially disposed at a lower surface  1204  of the abrasive particle  203  adjacent the substrate  201  and first layer  202 . Notably, the particle coating layer  1205  may not necessarily extend over an upper surface  1203  of the abrasive particle  203 , which is spaced at a greater distance from the substrate  201  than the lower surface  1204 , and facilitate the formation of the exposed surface  1201 . The particle coating layer  1205  may be removed from the upper surface  1203  of the abrasive particle via a selective removal process prior to forming the bonding layer as described in embodiments herein. The absence of a the particle coating layer  1205  at the upper surface  1203  can facilitate the formation of an exposed surface  1201 , since the bonding layer material may not necessarily wet the upper surface  1203  of the abrasive particle  203  during forming. 
     According to one embodiment, the exposed surface  1201  can be essentially absent a metal material. In particular, the exposed surface  1201  can consist essentially of the abrasive particle  203  and have no overlying layers. In certain instances, the exposed surface  1201  can consist essentially of diamond. 
       FIG. 12B  includes a picture of an abrasive article according to an embodiment including abrasive particles having exposed surfaces. The exposed surfaces  1201  can exist for at least about 5% of an amount of abrasive particles of the abrasive article. It will be appreciated that the amount of abrasive particles can be a total amount of only the first type of abrasive particles, a total amount of only the second type of abrasive particles, or a total amount of all types of abrasive particles present in the abrasive article. In other instances, the content of abrasive particles having an exposed surface can be at least about 10%, such as at least about 20%, at least about 30%, at least about 40%, at least about 50%, at least about 60%, at least about 70%, at least about 80%, or even at least about 90%. Still, in a non-limiting embodiment, not greater than about 99%, such as not greater than about 98%, not greater than about 95%, not greater than about 80%, such as not greater than about 70%, not greater than about 60%, not greater than about 505, not greater than about 40%, not greater than about 30%, not greater than about 25%, or even not greater than about 20% of an amount of the abrasive particles have an exposed surface. It will be appreciated that the amount of abrasive particles having an exposed surface can be within a range between any of the above noted minimum and maximum percentages. 
     The bonding layer may have a particular contour at the exposed surface  1201 . As illustrated in  FIG. 12B , the bonding layer  205  can have a scalloped edge  1205  at an interface between the bonding layer  205  and an exposed surface  1201  of the abrasive particles. The scalloped edge may facilitate improved material removal and improved abrasive particle retention. 
     Certain processing techniques can facilitate use of different types of abrasive particles having different exposed surfaces. For example, the abrasive article can include a first type of abrasive particle and a second type of abrasive particle, wherein essentially none of the total content of the second type of abrasive particle has an exposed surface while at least a portion of the total content of the first type of abrasive particle has an exposed surface. Still, in other instances, at least a portion of a total amount of the second type of abrasive particle can have an exposed surface. Moreover, in one particular embodiment, the amount of the second type of abrasive particle having an exposed surface is less than the amount of the first type of abrasive particle having an exposed surface. Alternatively, the amount of the second type of abrasive particle having an exposed surface is greater than the amount of the first type of abrasive particle having an exposed surface. Yet, according to another embodiment, the total amount of the second type of abrasive particle having an exposed surface is substantially the same as the amount of the first type of abrasive particle having an exposed surface. 
     The abrasive articles of the embodiments herein may be wire saws that are particularly suited for slicing of workpieces. The workpieces can be various materials, including but not limited to, ceramic, semiconductive material, insulating material, glass, natural materials (e.g., stone), organic material, and a combination thereof. More particularly, the workpieces can include oxides, carbides, nitrides, minerals, rocks, single crystalline materials, multicrystalline materials, and a combination thereof. For at least one embodiment, an abrasive article of an embodiment herein may be suitable for slicing a workpiece of sapphire, quartz, silicon carbide, and a combination thereof. 
     According to at least one aspect, the abrasive articles of the embodiments can be used on particular machines, and may be used at particular operating conditions that have improved and unexpected results compared to conventional articles. While not wishing to be bound to a particular theory, it is thought there may be some synergistic effect between the features of the embodiments. 
     Generally, cutting, slicing, bricking, squaring, or any other operation can be conducted by moving the abrasive article (i.e., wire saw) and the workpiece relative to each other. Various types and orientations of the abrasive articles relative to the workpieces may be utilized, such that a workpiece is sectioned into wafers, bricks, rectangular bars, prismatic sections, and the like. 
     This may be accomplished using a reel-to-reel machine, wherein moving comprises reciprocating the wire saw between a first position and a second position. In certain instances, moving the abrasive article between a first position and a second position comprises moving the abrasive article back and forth along a linear pathway. While the wire is being reciprocated, the workpiece may also be moved, including for example, rotating the workpiece.  FIG. 15  includes an illustration of a reel-to-reel machine using an abrasive article to slice a workpiece. 
     Alternatively, an oscillating machine may be utilized with any abrasive article according to the embodiments herein. Use of an oscillating machine can include moving the abrasive article relative to the workpiece between a first position and second position. The workpiece may be moved, such as rotated, and moreover the workpiece and wire can both be moved at the same time relative each other. An oscillating machine may utilize a back and forth motion of the wire guide relative to the workpiece, wherein a reel-to-reel machine does not necessarily utilize such a motion.  FIG. 16  includes an illustration of an oscillation machine using an abrasive article to slice a workpiece. 
     For some applications, during the slicing operation the process may further include providing a coolant at an interface of the wire saw and workpiece. Some suitable coolants include water-based materials, oil-based materials, synthetic materials, and a combination thereof. 
     In certain instances, slicing can be conducted as a variable rate operation. The variable rate operation can include moving the wire and workpiece relative to each other for a first cycle and moving the wire and workpiece relative to each other for a second cycle. Notably, the first cycle and the second cycle may be the same or different. For example, the first cycle can include translation of the abrasive article from a first position to a second position, which in particular, may include translation of the abrasive article through a forward and reverse direction cycle. The second cycle can include translation of the abrasive article from a third position to a fourth position, which may also include translation of the abrasive article through a forward and reverse direction cycle. The first position of the first cycle can be the same as the third position of the second cycle, or alternatively, the first position and the third position may be different. The second position of the first cycle can be the same as the fourth position of the second cycle, or alternatively, the second position and the fourth position may be different. 
     According to a particular embodiment, the use of an abrasive article of an embodiment herein in a variable rate cycle operation can include a first cycle that includes the elapsed time to translate the abrasive article from a starting position in a first direction (e.g., forward) to a temporary position, and in a second direction (e.g., backward) from the temporary position, thus returning to the same starting position or close to the starting position. Such a cycle can include the duration for accelerating the wire from 0 m/s to set wire speed in the forward direction, the elapsed time for moving the wire at set wire speed in the forward direction, the elapsed time on decelerating the wire from set wire speed to 0 m/s in the forward direction, the elapsed time on accelerating the wire from 0 m/s to set wire speed in the backward direction, the elapsed time on moving the wire at set wire speed in the backward direction, and the elapsed time on decelerating the wire from set wire speed to 0 m/s in the backward direction.  FIG. 17  includes an exemplary plot of wire speed versus time for a single cycle of a variable rate cycle operation. 
     According to one particular embodiment, the first cycle can be at least about 30 seconds, such as at least about 60 seconds, or event least about 90 seconds. Still, in one non-limiting embodiment, the first cycle can be not greater than about 10 minutes. It will be appreciated that the first cycle can have a duration within a range between any of the minimum and maximum values above. 
     In yet another embodiment, the second cycle can be at least about 30 seconds, such as at least about 60 seconds, or even at least about 90 seconds. Still, in one non-limiting embodiment, the second cycle can be not greater than about 10 minutes. It will be appreciated that the second cycle can have a duration within a range between any of the minimum and maximum values above. 
     The total number of cycles in a for a cutting process may vary, but can be at least about 20 cycles, at least about 30 cycles, or even at least about 50 cycles. In particular instances, the number of cycles may be not greater than about 3000 cycles or not greater than about 2000 cycles. The cutting operation may last for a duration of at least about 1 hour or at least about 2 hours. Still, depending upon the operation, the cutting process may be longer, such as at least about 10 hours, or even 20 hours of continuous cutting. 
     In certain cutting operations, the wire saw of any embodiment herein may be particularly suited for operation at a particular feed rate. For example, the slicing operation can be conducted at a feed rate of at least about 0.05 mm/min, at least about 0.1 mm/min, at least about 0.5 mm/min, at least about 1 mm/min, or even at least about 2 mm/min Still, in one non-limiting embodiment, the feed rate may be not greater than about 20 mm/min. It will be appreciated that the feed rate can be within a range between any of the minimum and maximum values above. 
     For at least one cutting operation, the wire saw of any embodiment herein may be particularly suited for operation at a particular wire tension. For example, the slicing operation can be conducted at a wire tension of at least about 30% of a wire break load, such as at least about 50% of the wire break load, or even at least about 60% of a break load. Still, in one non-limiting embodiment, the wire tension may be not greater than about 98% of the break load. It will be appreciated that the wire tension can be within a range between any of the minimum and maximum percentages above. 
     According to another cutting operation, the abrasive article can have a VWSR range that facilitates improved performance. VWSR is the variable wire speed ratio and can generally be described by the equation t2/(t1+t3), wherein t2 is the elapsed time when the abrasive wire moves forward or backward at a set wire speed, wherein t1 is the elapsed time when the abrasive wire moves forward or backward from 0 wire speed to set wire speed, and t3 is the elapsed time when the abrasive wire moves forward or backward from constant wire speed to 0 wire speed. See, for example  FIG. 17 . For example, the VWSR range of a wire saw according to an embodiment herein can be at least about 1, at least about 2, at least about 4, or even at least about 8. Still, in one non-limiting embodiment, the VWSR rate may be not greater than about 75 or not greater than about 20. It will be appreciated that the VWSR rate can be within a range between any of the minimum and maximum values above. In one embodiment, an exemplary machine for variable wire speed ratio cutting operations can be a Meyer Burger DS265 DW Wire Saw machine. 
     Certain slicing operations may be conducted on workpieces including silicon, which can be single crystal silicon or multicrystalline silicon. According to one embodiment, use of an abrasive article according to an embodiment demonstrates a life of at least about 8 m 2 /km, such as at least about 10 m 2 /km, at least about 12 m 2 /km, or even at least about 15 m 2 /km. The wire life can be based upon the wafer area generated per kilometer of abrasive wire used, wherein wafer area generated is calculated based on one side of the wafer surface. In such instances, the abrasive article may have a particular abrasive particle concentration, such as at least about 0.5 carats per kilometer of the substrate, at least about 1.0 carats per kilometer of substrate, at least about 1.5 carats per kilometer of substrate, or even at least about 2.0 carats per kilometer of substrate. Still, the concentration may be not greater than about 20 carats per kilometer of substrate, or even not greater than about 10 carats per kilometer of substrate. The average particle size of the abrasive particles can be less than about 20 microns. It will be appreciated that the abrasive particle concentration can be within a range between any of the minimum and maximum values above. The slicing operation may be conducted at a feed rate as disclosed herein. 
     According to another operation, a silicon workpiece including single crystal silicon or multicrystalline silicon can be sliced with an abrasive article according to one embodiment, and the abrasive article can have a life of at least about 0.5 m 2 /km, such as at least about 1 m 2 /km, or even at least about 1.5 m 2 /km. In such instances, the abrasive article may have a particular abrasive particle concentration, such as at least about 5 carats per kilometer of the substrate, at least about 10 carats per kilometer of substrate, of at least about 20 carats per kilometer of substrate, at least about 40 carats per kilometer of substrate. Still, the concentration may be not greater than about 300 carats per kilometer of substrate, or even not greater than about 150 carats per kilometer of substrate. The average particle size of the abrasive particles can be less than about 20 microns. It will be appreciated that the abrasive particle concentration can be within a range between any of the minimum and maximum values above. 
     The slicing operation may be conducted at a feed rate of at least about 1 mm/min, at least about 2 mm/min, at least about 3 mm/min, at least about 5 mm/min. Still, in one non-limiting embodiment, the feed rate may be not greater than about 20 mm/min. It will be appreciated that the feed rate can be within a range between any of the minimum and maximum values above. 
     According to another operation, a sapphire workpiece can be sliced using an abrasive article of an embodiment herein. The sapphire workpiece may include a c-plane sapphire, an a-plane sapphire, or a r-plane sapphire material. For at least one embodiment, the abrasive article can slice through the sapphire workpiece and exhibit a life of at least about 0.1 m 2 /km, such as at least about 0.2 m 2 /km, at least about 0.3 m 2 /km, at least about 0.4 m 2 /km, or even at least about 0.5 m 2 /km. In such instances, the abrasive article may have a particular abrasive particle concentration, such as at least about 5 carats per kilometer of the substrate, at least about 10 carats per kilometer of substrate, of at least about 20 carats per kilometer of substrate, at least about 40 carats per kilometer of substrate. Still, the concentration may be not greater than about 300 carats per kilometer of substrate, or even not greater than about 150 carats per kilometer of substrate. The average particle size of the abrasive particles can be greater than about 20 microns. It will be appreciated that the abrasive particle concentration can be within a range between any of the minimum and maximum values above. 
     The foregoing slicing operation on the workpiece of sapphire may be conducted at a feed rate of at least about 0.05 mm/min, such as at least about 0.1 mm/min, or even at least about 0.15 mm/min. Still, in one non-limiting embodiment, the feed rate may be not greater than about 2 mm/min. It will be appreciated that the feed rate can be within a range between any of the minimum and maximum values above. 
     In yet another aspect, the abrasive article may be used to slice through workpieces including silicon carbide, including single crystal silicon carbide. For at least one embodiment, the abrasive article can slice through the silicon carbide workpiece and exhibit a life of at least about 0.1 m 2 /km, such as at least about 0.2 m 2 /km, at least about 0.3 m 2 /km, at least about 0.4 m 2 /km, or even at least about 0.5 m 2 /km. In such instances, the abrasive article may have a particular abrasive particle concentration, such as at least about 5 carats per kilometer of the substrate, at least about 10 carats per kilometer of substrate, of at least about 20 carats per kilometer of substrate, at least about 40 carats per kilometer of substrate. Still, the concentration may be not greater than about 300 carats per kilometer of substrate, or even not greater than about 150 carats per kilometer of substrate. It will be appreciated that the abrasive particle concentration can be within a range between any of the minimum and maximum values above. 
     The foregoing slicing operation on the workpiece of silicon carbide may be conducted at a feed rate of at least about 0.05 mm/min, such as at least about 0.10 mm/min, or even at least about 0.15 mm/min. Still, in one non-limiting embodiment, the feed rate may be not greater than about 2 mm/min. It will be appreciated that the feed rate can be within a range between any of the minimum and maximum values above. 
     Abrasive articles of the embodiments herein have demonstrated improved abrasive particle retention during use as compared to conventional abrasive wire saws without at least one of the features of the embodiments herein. For example, the abrasive articles have an abrasive particle retention of at least about 2% improvement over one or more conventional samples. In still other instances, the abrasive particle retention improvement can be at least about 4%, at least about 6%, at least about 8%, at least about 10%, at least about 12%, at least about 14%, at least about 16%, at least about 18%, at least about 20%, at least about 24%, at least about 28%, at least about 30%, at least about 34%, at least about 38%, at least about 40%, at least about 44%, at least about 48%, or even at least about 50%. Still, in one non-limiting embodiment, the abrasive particle retention improvement can be not greater than about 100%, such as not greater than about 95%, not greater than about 90%, or even not greater than about 80%. 
     Abrasive articles of the embodiments herein have demonstrated improved abrasive particle retention and further demonstrated improved useable life compared to conventional abrasive wire saws without at least one of the features of the embodiments herein. For example, the abrasive articles herein can have an improvement of useable life of at least about 2% compared to one or more conventional samples. In still other instances, the increase in useable life of an abrasive article of an embodiment herein compared to a conventional article can be at least about 4%, at least about 6%, at least about 8%, at least about 10%, at least about 12%, at least about 14%, at least about 16%, at least about 18%, at least about 20%, at least about 24%, at least about 28%, at least about 30%, at least about 34%, at least about 38%, at least about 40%, at least about 44%, at least about 48%, or even at least about 50%. Still, in one non-limiting embodiment, the useable life improvement can be not greater than about 100%, such as not greater than about 95%, not greater than about 90%, or even not greater than about 80%. 
     In accordance with another embodiment, a method of forming abrasive articles of embodiments described herein may include providing a body including abrasive particles overlying a first layer, the first layer overlying a substrate. It will be noted that in certain embodiments, the first layer may be referred to as a tacking layer. The method may further include processing at least the substrate, the first layer, and the abrasive particles according to a controlled processing condition to form an abrasive article having a fillet characteristic. 
     The fillet characteristic may be selected from the group consisting of a tacking factor (t fl /t f ), a fillet-to-particle factor (t f /d ab ), a fillet-to-bonding layer factor (t f /t bl ), a contact factor (A b /A f ), a fillet size variance (V f ) and a combination thereof. It will be noted that in certain instances, the fillet characteristic can be based upon a predetermined value. It will be further noted that in other instances, the fillet characteristic may be related to one or more controlled processing conditions. 
     The fillet characteristics of the embodiments herein may be calculated from measurements taken from a cross-sectional image of an abrasive article.  FIG. 18 a    includes an illustration of a cross-sectional image of an abrasive article  1800 . The illustration of  FIG. 18 a    provides measurements that may be taken on a cross-sectional image of any embodiment of an abrasive article described herein to calculate the fillet characteristics noted herein. Referring to  FIG. 18 a   , the abrasive article  1800  may include a substrate  1810 , an abrasive particle  1815 , a first layer  1820  overlaying the substrate  1810 , and a second layer  1825  overlaying the first layer  1820  and the abrasive particle  1815 . Notably, cross-sectional images to be used for calculating the fillet characteristics as described in embodiments herein, are preferably based upon images where a surface of the abrasive particle  1815  is in contact with the substrate  1810  or in contact with the first layer  1820 . The image may further show fillets  1830 ,  1832  contacting the substrate  1810  and the abrasive particle  1815 . 
       FIG. 18 b    includes an illustration of a magnified portion of  FIG. 18 a   , particularly, the portion of abrasive article  1800  near abrasive particle  1815 . 
     The substrate  1810  may include a center point  1835 , approximately equidistance from any point along an outer perimeter  1840  of the substrate  1810 . A radial axis  1845  may extend outward from the center point  1835  and cross the outer perimeter  1840  of the substrate  1810  at an angle perpendicular to any line tangential to the outer perimeter  1940  of the substrate  1810 . First layer  1820  may have a thickness d fl  measured as the distance along the radial axis  1845  between the outer perimeter  1840  of the substrate  1810  and an outer perimeter  1850  of the first layer  1820 . The value t fl  represents the average thickness of first layer  1820  calculated from a suitable sample size of d fl  measurements made at various locations around the first layer  1820  spaced away from the abrasive particle  1815 . For instance, in one non-limiting example, the t fl  value may be calculated from a sample size of greater than about 10 d fl  measurements around the first layer  1820  spaced away from the abrasive particle  1815 . 
     A radial axis  1855  may extend outward from the center point  1835  and cross the outer perimeter  1840  of the substrate  1810  at an angle perpendicular to any line tangential to the outer perimeter  1840  of the substrate  1810 . Second layer  1825  may have a thickness d bl  measured as the distance along the radial axis  1855  between the outer perimeter  1850  of the first layer  1820  and an outer perimeter  1860  of the second layer  1825 . The value t bl  represents the average thickness of the second layer  1825  calculated from a suitable sample size of d bl  measurements made at various locations around the second layer  1825  spaced away from the abrasive particle  1815 . For instance, in one non-limiting example, the t bl  value may be calculated from a sample size of greater than about 10 d bl  measurements around the second layer  1825  spaced away from the abrasive particle  1815 . 
     Each abrasive particle  1815 , having fillets  1830 ,  1832 , may have a single d f  measurement representing the maximum fillet thickness of the abrasive particle  1815 . The d f  measurement can be the greater of the distance between the outer perimeter  1840  of the substrate  1810  and a triple point  1870  or the distance between the outer perimeter  1840  of the substrate  1810  and a triple point  1872 . It will be appreciated that triple points  1870 ,  1872  may be defined as the points of common contact between an abrasive particle  1815 , fillets  1830  or  1832 , and the second layer  1825  as viewed in a cross-sectional image. The d f  measurement for an abrasive particle  1815  may be measured along a radial axis  1865  that extends from the center point  1835  to whichever of triple points  1870  or  1872  is farthest away from the outer perimeter  1840  of substrate  1810 . For example, referring specifically to  FIG. 19 , triple point  1870  is farther than triple point  1872  from the outer perimeter  1840  of substrate  1810 . Therefore, the d f  measurement for abrasive particle  1815  may be measured along a radial axis  1865  that extends from the center point  1835  to triple point  1870 . The d f  measurement for abrasive particle  1815  is equal to the distance along radial axis  1865  between the outer perimeter  1840  of substrate  1810  and triple point  1870 . 
     The value t f  represents the average maximum fillet thickness for the abrasive article calculated from a statistically relevant sample size of abrasive particles  1815  and their associated d f  measurements. For instance, in one non-limiting example, the t f  value may be calculated from a sample size of abrasive particles of greater than 10 abrasive particles  1815  and their associated d f  measurements. 
     Each abrasive particle  1815  may have an a b  measurement that represents the surface area of the abrasive particle  1815  in contact with the second layer  1825 . Each abrasive particle  1815  may also have an a f  measurement that represents the surface area of the abrasive particle  1815  in contact with the fillets  1830 ,  1832 . The a b  and a f  measurements may be taken from a cross-sectional image of the abrasive particle  1815  using any suitable imaging instrument, such as a scanning electron microscope, to perform image analysis of the abrasive particle  1815 . 
     The value A b  represents the average percentage of the surface area of abrasive particles in contact with the second layer  1825  and may be calculated from a statistically relevant sample size of abrasive particles  1815  and their associated a b  measurements. For instance, in one non-limiting example, the A b  value may be calculated from a sample size of greater than 10 abrasive particles  1815  and their associated a b  measurements. The value A f  represents the average percentage of the surface area of abrasive particles in contact with fillets  1830 ,  1832  and may be calculated from a statistically relevant sample size of abrasive particles  1815  and their associated a f  measurements. For instance, in one non-limiting example, the A f  value may be calculated from a sample size of greater than 10 abrasive particles  1815  and their associated a f  measurements. 
     The value d ab  represents the average particle size of abrasive particles in the abrasive article  1800 . The average particle size d ab  can be a median (D50) or may be represented by the diameter of the particle as shown in  FIGS. 18 a  and 18 b   . The value V f  represents the fillet size variance (V f ) and may be expressed mathematically as [(Fmax−Favg)/Fmax]×100%. Fmax represents a greatest value of fillet thickness of a sample and Favg represents the average maximum thickness of the fillets of a sample. 
     It will be appreciated that abrasive particles  1815  may be coated abrasive particles as described herein. For purposes of determining fillet factors according to embodiments disclosed herein, any such coating on an abrasive particle up to and including a thickness of about 0.3 μm from the surface of the abrasive particle will be considered part of the abrasive particle. Therefore, for purposes of any measurements, including, but not limited to, t fl , t bl , t f , D ab , A b , or A f , any coating of the abrasive particle  1815 , for example, a tin coating, up to and including a thickness of about 0.3 μm from the surface of the abrasive particle, will not be considered or included in the required measurements. Further, in certain embodiments, it will be appreciated that the triple point may be defined as the points of common contact between a coating of an abrasive particle  1815  up to and including a thickness of about 0.3 μm from the surface of the abrasive particle, fillets  1830  or  1832 , and the second layer  1825  as viewed in a cross-sectional image. 
     It will be further appreciated that all average values described herein, for example, t fl , t bl , t f , d ab , A b  or A f , may also refer to mean values or median values. For example, d ab  can be a median (D50) value of the abrasive particles of the abrasive article. It will be further appreciated that all averages described herein may be calculated from a suitable sample size of values, for example, a sample size of greater than about 10 values. 
     It will be further appreciated that the measurements noted herein for determining fillet characteristics may be taken from cross-sectional images of abrasive articles under a magnification in the range of 100× to about 1000×. It will be further appreciated that the measurements noted herein for determining fillet characteristics may be preferably taken from cross-sectional images of abrasive articles under a magnification of about 300×. 
     It will be further appreciated that the fillet characteristics noted above may be related to one or more controlled processing conditions. In certain embodiments, the fillet characteristic may be selected based on control of one or more controlled processing conditions. In still other embodiments, the fillet characteristic can be a predetermined fillet characteristic, which may be based upon a user-selected value prior to forming the abrasive article and which may be determined based upon control of one or more controlled processing conditions. 
     Accordingly to particular embodiments, the one or more controlled processing condition may be selected from the group consisting of re-flow temperature, filler content, filler size, filler composition, average particle size of the abrasive particles, size distribution of the abrasive particles, content of the abrasive particles, composition of the abrasive particles, thickness of the first layer, composition of the first layer, atmospheric conditions, and a combination thereof. In certain embodiments, the one or more controlled processing condition, for example, re-flow temperature, may be user controlled to control a fillet characteristic, for example a tacking factor (t fl /t f ) for the abrasive article. The value of the fillet characteristic may thus be user controlled or selected based upon an expected or predetermined abrasive application, for example, diamond wire for sapphire or silicon wafer sawing. 
     According to a particular embodiment, the expected or predetermined abrasive application may be based upon at least one parameter selected from the group consisting of a workpiece hardness, a workpiece size, workpiece composition, abrasive article life, abrasive particle retention strength, cutting force an workpiece quality. 
     In a particular embodiment, the fillet characteristic may be a tacking factor expressed mathematically as t fl /t f . In certain non-limiting embodiments, the tacking factor may be at least about 0.01, such as, at least about 0.02, at least about 0.03, at least about 0.04, at least about 0.05, at least about 0.1, at least about 0.2, at least about 0.3, at least about 0.4, at least about 0.5, at least about 0.6, at least about 0.7, at least about 0.8, at least about 0.9, at least about 1.0, at least about 1.1, at least about 1.2, at least about 1.3, at least about 1.4, at least about 1.5, at least about 1.6, at least about 1.7, at least about 1.8 or even at least about 1.9. In still other non-limiting embodiments, the tacking factor may be not greater than about 2, such as, not greater than about 1.9, not greater than about 1.8, not greater than about 1.7, not greater than about 1.6, not greater than about 1.5, not greater than about 1.4, not greater than about 1.3, not greater than about 1.2, not greater than about 1.1, not greater than about 1, not greater than about 0.9, not greater than about 0.8, not greater than about 0.7, not greater than about 0.6, not greater than about 0.5, not greater than about 0.4, not greater than about 0.3 or even not greater than about 0.2. It will be appreciated that the tacking factor may be any value within a range between any of the minimum and maximum values noted above. 
     According to another particular embodiment, the fillet characteristic may be a fillet-to-particle factor expressed mathematically as t f /d ab . In certain non-limiting embodiments, the fillet-to-particle factor may be at least about 0.01, such as, at least about 0.02, at least about 0.03, at least about 0.04, at least about 0.05, at least about 0.06, at least about, at least about 0.08, at least about 0.1, at least about 0.12, at least about 0.15, at least about 0.2, at least about 0.25, at least about 0.3, at least about 0.35, at least about 0.4, at least about 0.45, at least about 0.5 or even at least about 0.55. In still other non-limiting embodiments, the fillet-to-particle factor may be not greater than about 1, such as, not greater than about 0.95, not greater than about 0.9, not greater than about 0.85, not greater than about 0.80, not greater than about 0.75, not greater than about 0.7, not greater than about 0.7, not greater than about 0.65, or even not greater than about 0.6. It will be appreciated that the fillet-to-particle factor may be any value within a range between any of the minimum and maximum values noted above. 
     According to another particular embodiment, the fillet characteristic may be a contact factor expressed mathematically as A b /A f . In certain non-limiting embodiments, the contact factor may be not greater than about 100, such as, not greater than about 95, not greater than about 90, not greater than about 85, not greater than about 80, not greater than about 75, not greater than about 70, not greater than about 65, not greater than about 60, not greater than about 55, not greater than about 50, not greater than about 45, not greater than about 40, not greater than about 35, not greater than about 30, not greater than about 25, not greater than about 20, not greater than about 15 or even not greater than about 10. In still other non-limiting embodiments, the contact factor may be at least about 0.01, such as, at least about 0.02, at least about 0.05, at least about 0.08, at least about 0.1, at least about 0.15, at least about 0.2, at least about 0.25, at least about 0.3, at least about 0.35, at least about 0.4, at least about 0.45, at least about 0.5, at least about 0.55, at least about 0.6, at least about 0.65, at least about 0.7, at least about 0.75, at least about 0.8, at least about 0.85, at least about 0.9 or even at least about 0.95. It will be appreciated that the contact factor may be any value within a range between any of the minimum and maximum values noted above. 
     According to another particular embodiment, the fillet characteristic may be a fillet-to-bonding layer factor expressed mathematically as t f /t bl . In certain non-limiting embodiments, the fillet-to-bonding layer factor may be at least about 0.01, such as, at least about 0.02, at least about 0.05, at least about 0.1, at least about 0.15, at least about 0.2, at least about 0.25, at least about 0.3, at least about 0.35, at least about 0.4, at least about 0.45, or even at least about 0.5. In still other non-limiting embodiments, the fillet-to-bonding layer factor may be not greater than about 100, such as, not greater than about 80, not greater than about 60, not greater than about 40, not greater than about 20, not greater than about 10, not greater than about 5, not greater than about 4, not greater than about 3.5, not greater than about 3, not greater than about 2.8, not greater than about 2.6, not greater than about 2.4, not greater than about 2.2, not greater than about 2, not greater than about 1.9, not greater than about 1.8, not greater than about 1.7, not greater than about 1.6, not greater than about 1.5, not greater than about 1.4, not greater than about 1.3, not greater than about 1.2 or even not greater than about 1.1. It will be appreciated that the fillet-to-bonding layer factor may be any value within a range between any of the minimum and maximum values noted above. 
     According to another particular embodiment, the fillet characteristic may be the fillet size variance (V f ) expressed mathematically as [(Fmax−t f )/Fmax]×100%. Fmax represents a greatest value of fillet thickness of a sampling and t f  is an average maximum fillet size as described herein. It will be appreciated that a sampling is reference to a statistical sample size of fillets taken from the abrasive article of a suitable number to derive a statistically relevant average. As noted herein, in one non-limiting example, the sampling can include at least 10 different measurements. In certain non-limiting embodiments, the fillet size variance (V f ) may be not greater than about 95%, such as, not greater than about 93%, not greater than about 90%, not greater than about 88%, not greater than about 85%, not greater than about 83%, not greater than about 80%, not greater than about 78%, not greater than about 75%, not greater than about 73%, not greater than about 70%, not greater than about 68%, not greater than about 65%, not greater than about 63%, not greater than about 60%, not greater than about 58%, not greater than about 55%, not greater than about 53%, not greater than about 50%, not greater than about 48%, not greater than about 45%, not greater than about 43%, not greater than about 40%, not greater than about 30%, not greater than about 20%, not greater than about 10%. In still other non-limiting embodiments, the fillet size variance (V f ) may be at least about 2%, at least about 5%, at least about 10%, at least about 20%, at least about 30%, at least about 40% or even at least about 50%. It will be appreciated that the fillet size variance (V f ) may be any percentage within a range between any of the minimum and maximum percentages noted above 
     In other embodiments, the abrasive article may further including a combination of at least two fillet characteristics from the group consisting of a tacking factor (t fl /t f ), a fillet-to-particle factor (t f /d ab ), a fillet-to-bonding layer factor (t f /t bl ), a contact factor (A b /A f ) or a fillet size variance (V f ). 
     As noted above, the fillet characteristic may be selected from the group consisting of fillet characteristics having predetermined values. For example, the fillet characteristic may be selected from the group consisting of a tacking factor (t fl /t f ) of not greater than about 1.5, a fillet-to-particle factor (t f /d ab ) of not greater than about 0.33, a fillet-to-bonding layer factor (t f /t bl ) of not greater than about 100, a contact factor (A b /A f ) of at least about 1, a fillet size variance (V f ) of not greater than 60% or a combination thereof. It will be noted that in certain instances, the fillet characteristic can be based upon a predetermined value. It will be further noted that in other instances, the fillet characteristic may be related to one or more controlled processing conditions. 
     In certain embodiments, the one or more controlled processing condition, for example, re-flow temperature, may be user controlled to produce the desired fillet characteristic having the predetermined value, for example a tacking factor (t fl /t f ) of not greater than about 1.5. 
     According to another particular embodiment, the desired fillet characteristic may be a tacking factor, expressed mathematically as t fl /t f , of not greater than about 1.5. For example, in certain non-limiting embodiments, the tacking factor may be not greater than about 1.4, not greater than about 1.3, not greater than about 1.2, not greater than about 1.1, not greater than about 1, not greater than about 0.99, not greater than about 0.97, not greater than about 0.95, not greater than about 0.92, not greater than about 0.9, not greater than about 0.85, not greater than about 0.8, not greater than about 0.75, not greater than about 0.7, not greater than about 0.65, not greater than about 0.6, not greater than about 0.55 or even not greater than about 0.51. In other non-limiting embodiments, the tacking factor may be at least about 0.5, such as, at least about 0.55, at least about 0.6, at least about 0.65, at least about 0.7, at least about 0.75, at least about 0.8, at least about 0.85, at least about 0.9, at least about 0.92, at least about 0.95, at least about 0.97, at least about 0.99, at least about 1, at least about 1.1, at least about 1.2, at least about 1.3 or even at least about 1.4. It will be appreciated that the tacking factor may be any value within a range between any of the minimum and maximum values noted above. 
     According to another particular embodiment, the desired fillet characteristic may be a fillet-to-particle factor, expressed mathematically as t f /d ab , of not greater than about 0.33. For example, in certain non-limiting embodiments, the fillet-to-particle factor may be not greater than about 0.31, not greater than about 0.3, not greater than about 0.27, not greater than about 0.25, not greater than about 0.23, not greater than about 0.2, not greater than about 0.17, not greater than about 0.15, not greater than about 0.13, not greater than about 0.1, not greater than about 0.07 or even not greater than about 0.06. In other non-limiting embodiments, the fillet-to-particle factor may be at least about 0.05, such as, at least about 0.07, at least about 0.1, at least about 0.12, at least about 0.14, at least about 0.16, at least about 0.18, at least about 0.20, at least about 0.24, at least about 0.26, at least about 0.28, at least about 0.30 or even at least about 0.32. It will be appreciated that the fillet-to-particle factor may be any value within a range between any of the minimum and maximum values noted above. 
     According to another particular embodiment, the desired fillet characteristic may be a fillet-to-bonding layer factor, expressed mathematically as t f /t bl , of not greater than about 100. For example, in certain non-limiting embodiments, the fillet-to-bonding layer factor may be not greater than about 90, not greater than about 80, not greater than about 70, not greater than about 60, not greater than about 50, not greater than about 40, not greater than about 35, not greater than about 30, not greater than about 28, not greater than about 26, not greater than about 24, not greater than about 22, not greater than about 20, not greater than about 18, not greater than about 16, not greater than about 14, not greater than about 12 or even not greater than about 11. In non-limiting embodiments, the fillet-to-bonding layer factor may be at least about 10, such as, at least about 12, at least about 14, at least about 16, at least about 18, at least about 20, at least about 22, at least about 24, at least about 26, at least about 28, at least about 30, at least about 35, at least about 40, at least about 45, at least about 50, at least about 60, at least about 70, at least about 80, at least about 90 or even at least about 95. It will be appreciated that the fillet-to-bonding layer factor may be any value within a range between any of the minimum and maximum values noted above. 
     According to another particular embodiment, the desired fillet characteristic may be a contact factor, expressed mathematically as A b /A f , of at least about 1.0. For example, in certain non-limiting embodiments, the contact factor may be at least about 1.2, at least about 1.4, at least about 1.5, at least about 1.6, at least about 1.7, at least about 1.8, at least about 1.9, at least about 2, at least about 2.2, at least about 2.4, at least about 2.6, at least about 2.8, at least about 3, at least about 3.5, at least about 4, at least about 5, at least about 6, at least about 7, at least about 8 or even at least about 9. In other non-limiting embodiments, the contact factor may be not greater than about 10, such as, not greater than about 9, not greater than about 8, not greater than about 7, not greater than about 6, not greater than about 5, not greater than about 4, not greater than about 3.5, not greater than about 3, not greater than about 2.8, not greater than about 2.6, not greater than about 2.4, not greater than about 2.3, not greater than about 2.2, not greater than about 2, not greater than about 1.9, not greater than about 1.8, not greater than about 1.7, not greater than about 1.6, not greater than about 1.5, not greater than about 1.4, not greater than about 1.3, not greater than about 1.2 or even not greater than about 1.1. It will be appreciated that the contact factor may be any value within a range between any of the minimum and maximum values noted above. 
     According to another particular embodiment, the fillet characteristic may be the fillet size variance (V f ) expressed mathematically as [(Fmax−t f )/Fmax]×100%. Fmax represents a greatest value of fillet thickness of a sampling and t f  is an average maximum fillet size as described herein. It will be appreciated that a sampling is reference to a statistical sample size of fillets taken from the abrasive article of a suitable number to derive a statistically relevant average. As noted herein, in one non-limiting example, the sampling can include at least 10 different measurements. In certain non-limiting embodiments, the fillet size variance (V f ) may be not greater than about 60%, such as, not greater than about 58%, not greater than about 55%, not greater than about 53%, not greater than about 50%, not greater than about 48%, not greater than about 45%, not greater than about 43%, not greater than about 40%, not greater than about 30%, not greater than about 20%, not greater than about 10%, not greater than about 8%, not greater than about 6%, not greater than about 4% or even not greater than about 3%. In still other non-limiting embodiments, the fillet size variance (V f ) may be at least about 2%, at least about 5%, at least about 10%, at least about 20%, at least about 30%, at least about 40% or even at least about 50%. It will be appreciated that the fillet size variance (V f ) may be any percentage within a range between any of the minimum and maximum percentages noted above. 
     In other embodiments, the abrasive article may further including a combination of at least two desired fillet characteristics having predetermined values selected from the group consisting of a tacking factor (t fl /t f ) of not greater than about 1.5, a fillet-to-particle factor (t f /d ab ) of not greater than about 0.33, a fillet-to-bonding layer factor (t f /t bl ) of not greater than about 100, a contact factor (A b /A f ) of at least about 1, a fillet size variance (V f ) of not greater than 60%. 
     According to another particular embodiment, the fillets may include a composition that is substantially the same as a composition of the first layer. In still other embodiments, the fillets may have a composition that is essentially the same as a composition of the first layer. In yet another embodiment, the fillets may include a composition having a difference in elemental composition of not greater than about 5 wt. % for any element compared to a composition of the first layer. Such as, for example, not greater than about 4 wt. %, not greater than about 3 wt. %, or even not greater than about 1 wt. % for a single element between the composition of the fillet and the composition of the first layer. It will be appreciated, that such a feature as the difference in composition between the first layer (i.e., the tacking layer) and the fillet may also exist between the fillet and the second layer (i.e., the bonding layer). It will be appreciated, that such a feature as the difference in composition between the first layer and the fillet may also exist between the fillet and a barrier layer. 
     According to another particular embodiment, the fillets may include a composition that is substantially different from a composition of the first layer. In still other embodiments, the fillets may have a composition that includes at least one element different than an element of the first layer. In yet another embodiment, the fillets may have a composition having a difference in elemental composition of at least about 5 wt. % for any element compared to a composition of the first layer. Such as, for example, at least about 6 wt. %, at least about 7 wt. %, at least about 8 wt. %, at least about 9 wt. %, at least about 10 wt. %, at least about 15 wt. %, at least about 20 wt. %, at least about 40 wt. % or even at least about 50 wt. % for a single element between the composition of the fillet and the composition of the first layer. It will be appreciated, that such a feature as the difference in composition between the first layer (i.e., the tacking layer) and the fillet may also exist between the fillet and the second layer (i.e., the bonding layer). It will be appreciated, that such a feature as the difference in composition between the first layer and the fillet may also exist between the fillet and a barrier layer. 
     According to another embodiment, the fillets may include an active bonding material. The active bonding material may include a material selected from the group consisting of borides, oxides, nitrides, carbides, oxynitrides, oxyborides, oxycarbides, and a combination thereof. For example, in one embodiment, the fillets may include an active bonding material including titanium. In another non-limiting embodiment, the fillets may include an active bonding material including titanium carbide. 
     According to another embodiment, the fillets may include a metal. In yet another embodiment, the fillets may include a metal alloy. In still another embodiment, the fillets may include an elemental metal. In yet another embodiment, the fillets may include one or more transition metal elements. For example, in certain instances, the fillets may include tin. In yet another embodiment, the fillets can include copper. In still another embodiment, the fillets may include nickel. In still another embodiment, the fillets may include solder. In still another embodiment, the fillets may include a mixture of tin and copper. 
     According to another embodiment, the fillets may include a mixture of a composition of the first layer and an active bonding material. In still another embodiment, the fillets may include at least two discrete phases of material. For example, the fillets may include a first phase and a second phase. In certain instances, the first phase may be preferentially located closer to a surface of the abrasive particles as compared to the second phase. In still other instances, the first phase preferentially located closer to a surface of the abrasive particle may be a material including the active bonding material or an element from the active bonding material, while the second phase, which is discrete from the first phase and has a separate composition compared to the first phase may, in some instances, be absent any elements of the active bonding material. In yet another embodiment, the fillets may include at least three discrete phases of material, including a first phase, a second phase, and a third phase. 
     According to another embodiment, the fillets may extend from the first layer. In other embodiments, the fillets may be integral with the first layer. In still other embodiments, the fillets may form an amalgamate with the first layer. 
     According to another embodiment the abrasive article may include a filler, which may be present in at least the first layer, or alternatively, may be present exclusively in the first layer. The filler may be distinct from the abrasive particles. In other embodiments, the filler may be distinct from the abrasive particles based on at least one filler criteria selected from the group consisting of average particle size, composition, content, concentration, distribution, and a combination thereof. 
     According to yet another embodiment, the abrasive particles may have an average particle size (P1) and the filler may have an average particle size (F1). In certain embodiments, the average particle size of the abrasive particles may be greater than the average particle size of the filler. In other embodiments, the average particle size of the abrasive particles may be at least about 5% different than the average particle size of the filler based on the equation ((P1−F1)/P1)×100%. In still other embodiments, the average particle size of the abrasive particles may be at least about 10% different, at least about 20% different, at least about 30% different, at least about 40% different, at least about 50% different, at least about 60% different, at least about 70% different, at least about 80% different, at least about 90% different or even at least about 95% different. In still other embodiments, the average particle size of the abrasive particles may not greater than about 99% different, such as, not greater than about 95% different, not greater than about 90% different, not greater than about 80% different, not greater than about 70% different, not greater than about 60% different, not greater than about 50% different, not greater than about 50% different, not greater than about 40% different, not greater than about 30% different, not greater than about 20% different or even not greater than about 10% different. It will be appreciated percentage difference between the average particle size of the abrasive particles and the average particle size of the filler may be any value within a range between any of the maximum and minimum values noted above. 
     According to another embodiment, the filler may have an average particle size of not greater than about 500 microns, such as, not greater than about 300 microns, not greater than about 200 microns, not greater than about 150 microns, not greater than about 100 microns, not greater than about 80 microns, not greater than about 50 microns, not greater than about 30 microns, not greater than about 20 microns, not greater than about 15 microns, not greater than about 12 microns, not greater than about 10 microns or even not greater than about 8 microns. In other embodiments, the filler may have an average particle size of at least about 0.01 microns, such as, at least about 0.05 microns, at least about 0.1 microns, at least about 0.5 microns, at least about 1 microns, at least about 3 microns, at least about 5 microns, at least about 8 microns, or even at least about 10 microns. It will be appreciated that the filler may have an average particle size of any value within a range of any of the minimum and maximum values noted above. 
     According to yet another embodiment, the filler may include a material selected from the group consisting of an inorganic material, an organic material, a polymer, a synthetic material, a natural material, and a combination thereof. In still another embodiment, the filler may include a material selected from the group consisting of a thermoplastic material, a thermoset material, a resin, a ceramic, a glass, a metal, a metal alloy, a metal coated particle, a substantially spherical bead, a hollow body, an elongated body, a fiber, and a combination thereof. It yet another embodiment, the filler may include a material selected from the group consisting of an oxide, a carbide, a nitride, a boride, diamond, a carbon-based material, cubic boron nitride, and a combination thereof. 
     According to another embodiment, the filler may include a Vickers hardness of at least about 0.1 GPa, such as, at least about 1 GPa or even at least about 3 GPa. In still another embodiment, the filler may include a Vickers hardness of not greater than about 200 GPa, such as, not greater than about 150 GPa or even not greater than about 100 GPa. It will be appreciated that the filler may have a Vickers hardness of any value within a range between any of the minimum and maximum values noted above. 
     According to another embodiment, the abrasive particles may have an average hardness (Hap) and the filler may have an average hardness (Hf). The average hardness of the abrasive particles (Hap) may be greater than the average hardness of the filler (Hf). In other embodiments, the average hardness of the abrasive particles may be at least about 5% different than the average hardness of the filler based on the equation ((Hap−Hf)/Hap)×100%. In still other embodiments, the average hardness of the abrasive particles may be at least about 10% different, at least about 20% different, at least about 30% different, at least about 40% different, at least about 50% different, at least about 60% different, at least about 70% different, at least about 80% different or even at least about 90% different than the average hardness of the filler. In yet other embodiments, the average hardness of the abrasive particles may be not greater than about 99% different, not greater tan about 90% different, not greater than about 80% different, not greater than about 70% different, not greater than about 60% different, not greater than about 60% different, not greater than about 50% different, not greater than about 40% different, not greater than about 30% different, or even, not greater than about 20% different than the average hardness of the filler. It will be appreciated that the percentage difference between the average hardness of the abrasive particles and the average hardness of the filler may be any value within a range between any of the minimum and maximum values noted above. 
     According to still another embodiment, the filler may have a filler composition distinct from an abrasive particle composition. In other embodiments, the filler composition may be different from the abrasive particle composition by at least 5 wt. % of at least one element within the filler composition and the abrasive particle composition. 
     According to yet another embodiment, the abrasive particles may be present in an abrasive particle content and the filler may be present in a filler content. The abrasive article may include an abrasive particle content greater than a filler content. In other embodiments, the filler content may be greater than the abrasive particle content. In still other embodiments, the abrasive particle content may be substantially the same as the filler content. In still other embodiments, the abrasive article may include a particle count ratio (Cap:Cf) of abrasive particle content (Cap) to filler content (Cf) of not greater than about 100:1, such as, not greater than about 50:1, not greater than about 20:1, not greater than about 10:1, not greater than about 5:1, not greater than about 2:1, or even about 1:1. In yet other embodiments, the particle count ratio (Cap:Cf) may be at least about 2:1, such as, at least about 5:1, at least about 10:1, at least about 20:1, at least about 50:1 or even at least about 100:1. It will be appreciated that the particle count ratio (Cap:Cf) may be any value within a range between any of the minimum and maximum values noted above. 
     In another embodiment, the concentration of filler on the elongated abrasive article can be at least about 0.00001 gram per meter, at least about 0.00002 gram per meter, at least about 0.00005 gram per meter, at least about 0.0001 gram per meter, at least about 0.0002 gram per meter, at least about 0.0005 gram per meter, at least about 0.001 gram per meter, at least about 0.002 gram per meter, at least about 0.005 gram per meter or even at least about 0.001 gram per meter. In still other embodiments, the concentration of filler on the elongate abrasive article can be not greater than about 0.1 gram per meter, not greater than about 0.05 gram per meter, not greater than about 0.02 gram per meter, not greater than about 0.01 gram per meter, not greater than about 0.005 gram per meter, not greater than about 0.002 gram per meter, or even not greater than about 0.001 gram per meter. It will be appreciated that the concentration of filler on the elongated abrasive article may be any value within a range between any of the minimum and maximum values noted above. 
     In other embodiments, the filler may have a greater wetting affinity for a composition of the first layer as compared to a wetting affinity of the abrasive particles. 
     For at least one embodiment, a particular method of forming may be utilized including one or more controlled processing conditions to facilitate formation of an abrasive article having particular fillet characteristics according to the embodiments herein. The process may be initiated as described generally in embodiments herein, with the formation of a first layer (e.g., a tacking layer) on the substrate, and placement of abrasive particles on the first layer. In accordance with one embodiment, one or more controlled processing conditions can be applied, which can facilitate certain fillet characteristics according to embodiments herein. For example, the controlled processing condition may include heating the substrate, the first layer, and the abrasive particles to a re-flow temperature. Heating the substrate, the first layer and the abrasive particles may include selecting a re-flow temperature and a viscosity, and controlling the wetting of the first layer on the abrasive particles. Heating the substrate, the first layer and the abrasive particles may further include selecting a re-flow temperature corresponding to a predetermined viscosity to control the wetting of the first layer on the abrasive particles and controlling the average maximum thickness of the fillets. 
     In other embodiments, the re-flow temperature may be different from a melting temperature of the first layer. In still other embodiments, the re-flow temperature may be different than the melting temperature by at least about 0.5% based on the equation [(Tm−Tr)/Tm]×100%. Tm represents the melting temperature and Tr represents the re-flow temperature. In other embodiments the re-flow temperature may be different than the melting temperature by at least about 1%, at least about 2%, at least about 3%, at least about 4%, at least about 5%, at least about 8%, at least about 10%, at least about 12%, at least about 15%, at least about 20%, at least about 30% or even at least about 40%. In still other embodiments, the re-flow temperature may be different than the melting temperature by not greater than about 80%, not greater than about 70%, not greater than about 60%, not greater than about 50%, not greater than about 40%, not greater than about 30%, not greater than about 20%, not greater than about 16%, not greater than about 14%, not greater than about 12%, not greater than about 10%, not greater than about 8% or even, not greater than about 6%. It will be appreciated that the re-flow temperature may be different than the melting temperature by any percentage within a range between any of the minimum and maximum values noted above. 
     According to other embodiments, the re-flow temperature may be not greater than about 450° C., such as, not greater than about 440° C., not greater than about 430° C., not greater than about 420° C., not greater than about 410° C., not greater than about 400° C., not greater than about 390° C., not greater than about 380° C., not greater than about 370° C., not greater than about 360° C., not greater than about 350° C., not greater than about 340° C., not greater than about 330° C., not greater than about 320° C., not greater than about 310° C. or even not greater than about 300° C. In other embodiments, the re-flow temperature is at least about 100° C., such as, at least about 120° C., at least about 150° C., at least about 180° C., at least about 200° C. or even at least about 220° C. It will be appreciated that the re-flow temperature may be any value within a range between any minimum or maximum value noted above. 
     According to other embodiments, processing according to the controlled processing condition may include changing a viscosity of the first layer and controlling the wetting of the abrasive particles by the first layer. Processing according to the controlled processing condition may further include increasing a viscosity of the first layer and controlling the amount of wetting of the abrasive particles by the first layer. 
     According to still other embodiments, processing according to the controlled processing condition may include providing a filler to control the wetting of the first layer on the abrasive particles. Processing according to the controlled processing condition may include selecting at least one of a filler composition, a filler size, and a filler content to control the wetting of the first layer on the abrasive particles. In other embodiments, processing according to the controlled processing condition may include providing a filler to control the average maximum thickness of the fillets. 
     In other embodiments, processing according to the controlled processing condition may include providing an atmospheric condition selected from the group consisting of a reducing atmosphere, an oxidizing atmosphere, an inert atmosphere, an atmosphere consisting essentially of one element, and a combination thereof. 
     According to other embodiments, the first layer may be configured to be a tacking layer. The tacking layer may provisionally hold the abrasive particles in place during processing. In other embodiments, the first layer may be in direct contact with a surface of the substrate. 
     According to other embodiments, the first layer may have an average thickness of not greater than about 80% of an average particle size of the abrasive particles. For example, in certain embodiments, the first layer may have an average thickness of not greater than about 70% or even not greater than about 40% of an average particle size of the abrasive particles. In still other embodiments, the first layer may have an average thickness of at least about 2%, such as, at least about 5%, at least about 6%, at least about 7%, at least about 8%, at least about 9%, at least about 10%, at least about 11%, at least about 12% or even, at least about 13% of an average particle size of the abrasive particles. It will be appreciated the average thickness of the first layer relative to the average particle size of the abrasive particles may be any value within a range between any of the minimum and maximum values noted above. 
     According to other particular embodiments, at least a portion of the abrasive particles may be spaced apart from an upper surface of the substrate. In still other embodiments, a majority of the abrasive particles may be spaced apart from an upper surface of the substrate. 
     In still other embodiments, the abrasive article may include undercut regions between an abrasive particle and a substrate. Undercut regions may be defined as either 1) a region of the second layer (e.g., the bonding layer) along a radial axis between an outermost point on an abrasive particle and the center point of the substrate, or 2) a region of void or empty space along a radial axis between an outermost point an abrasive particle and the center point of the core. 
       FIG. 19 a    includes an illustration of a cross-sectional image of an abrasive article  1900  having undercut regions between the abrasive particle and the substrate determined by the presence of the second layer between an outermost point on an abrasive particle and the center point of the substrate. Referring to  FIG. 19 a   , the abrasive article  1900  may include a substrate  1910 , an abrasive particle  1915 , a first layer  1920  overlaying the substrate  1910 , and a second layer  1925  overlaying the first layer  1920  and the abrasive particle  1915 . The image may further show undercut regions  1930 ,  1932  between the abrasive particle  1915  and the substrate  1910 . The substrate  1910  may include a center point  1935 , equidistance from any point along an outer perimeter  1940  of the substrate  1910 . A radial axis  1945  may extend outward from the center point  1935  to an outermost point  1947  on the abrasive particle  1915 . The abrasive article  1900  as illustrated in  FIG. 19 a    may be determined to have undercut regions  1930 ,  1932  wherein the radial axis  1945  passes through second layer  1925  between outermost point  1947  and center point  1935 . 
       FIG. 19 b    includes an illustration of a magnified portion of  FIG. 19 a   , particularly, the undercut region  1930  between the abrasive particle  1915  and the substrate  1910 . 
       FIG. 20 a    includes an illustration of a cross-sectional image of an abrasive article  1950  having undercut regions between the abrasive particle and the substrate determined by the presence of a void or empty space between an outermost point on an abrasive particle and the center point of the substrate. Referring to  FIG. 20 a   , the abrasive article  1950  may include a substrate  1960 , an abrasive particle  1965 , a first layer  1970  overlaying the substrate  1965 , and a second layer  1975  overlaying the first layer  1970  and the abrasive particle  1965 . The image may further show undercut regions  1980 ,  1982  between the abrasive particle  1965  and the substrate  1960 . The substrate  1960  may include a center point  1985 , equidistance from any point along an outer perimeter  1990  of the substrate  1960 . A radial axis  1995  may extend outward from the center point  1985  to an outermost point  1997  on the abrasive particle  1965 . The abrasive article  1950  as illustrated in  FIG. 20 a    may be determined to have undercut regions  1930 ,  1932  wherein the radial axis  1995  passes through an open space or void area between outermost point  1997  and center point  1985 . 
       FIG. 20 b    includes an illustration of a magnified portion of  FIG. 20 a   , particularly, the undercut region  1980  between the abrasive particle  1965  and the substrate  1960 . 
     According to other embodiments, at least about 55% of the abrasive particles may have an undercut region. In other embodiments, at least about 60%, of the abrasive particles may have an undercut region, such as, at least about 70%, at least about 80%, at least about 90% or even at least about 95% of the abrasive particles have an undercut region. In still other embodiments, not greater than about 99% of the abrasive particles may have an undercut region, such as, not greater than about 95%, not greater than about 90%, not greater than about 80%, not greater than about 70%, not greater than about 70%, not greater than about or even, not greater than about 60% of the abrasive particles have an undercut region. It will be appreciated that the percent of the abrasive particles that may have an undercut region may be any percentage within a range between any of the minimum and maximum values noted above. 
     EXAMPLE 1 
     A length of high strength carbon steel wire is obtained as a substrate. The high strength carbon steel wire has an average diameter of approximately 180 microns. A first layer is formed on the external surface of the substrate via electroplating. The electroplating process forms a first layer having an average thickness of approximately 3.75 microns. The first layer is formed of an essentially pure tin composition. 
     After forming the first layer, flux material is applied on the wire with nickel-coated diamond abrasive particles having an average particle size of between 30 to 40 microns. 
     Thereafter, the substrate, first layer, and abrasive particles undergo tin re-flow heating (diamond tacking) in a furnace at a temperature sufficient to heat the first layer to a re-flow temperature between 30° C. and 50° C. above the melting temperature of the first layer (i.e., melting temperature for tin is 232° C.). The abrasive pre-form is then cooled and rinsed. The process of bonding the nickel coated diamond to the first layer is conducted at an average spooling rate of 20 m/min. 
     Thereafter, the abrasive pre-form is washed using 20 wt % Sulfuric acid followed by a rinse with de-ionized water. The rinsed article is electroplated with nickel to form a bonding layer directly contacting and overlying the abrasive particles and first layer.  FIG. 21  includes a scanning electron microscopy of a portion of the abrasive article formed from the process of Example 1 taken at a magnification of 300×. 
     During the high temperature re-flow, the tin layer segregates around nickel coated diamond particles and forms large filets connecting diamond particles to the wire. The abrasive article has a tacking factor (t fl /t f ) of about 0.05, a fillet-to-particle factor (t f /d ab ) of about 0.8, a fillet-to-bonding layer factor (t f /t bl ) of 3, a contact factor (A b /A f ) of about 0.3. 
     EXAMPLE 2 
     A length of high strength carbon steel wire is obtained as a substrate. The high strength carbon steel wire has an average diameter of approximately 180 microns. A first layer is formed on the external surface of the substrate via electroplating. The electroplating process forms a first layer having an average thickness of approximately 3.75 microns. The first layer is formed of an essentially pure tin composition. 
     After forming the first layer, flux material is applied on the wire with nickel-coated diamond abrasive particles having an average particle size of between 30 to 40 microns. 
     Thereafter, the substrate, first layer, and abrasive particles undergo tin re-flow heating (diamond tacking) in a furnace at a temperature sufficient to heat the first layer to a re-flow temperature between 1° C. and 10° C. above the melting temperature of the first layer (i.e., melting temperature for tin is 232° C.). The abrasive pre-form is then cooled and rinsed. The process of bonding the nickel coated diamond to the first layer is conducted at an average spooling rate of 20 m/min. 
     Thereafter, the abrasive pre-form is washed using 20 wt % Sulfuric followed by a rinse with de-ionized water. The rinsed article is electroplated with nickel to form a bonding layer directly contacting and overlying the abrasive particles and first layer.  FIG. 22  includes scanning electron microscopy of a portion of the abrasive article formed from the process of Example 2 taken at a magnification of 300×. 
     Because the re-flow is done under relatively low temperature, the tin layer does not noticeably segregates around nickel coated diamond particles and the fillet connecting diamond particles to the wire is small. The abrasive article has a tacking factor (t fl /t f ) of about 1, a fillet-to-particle factor (t f /d ab ) of about 0.11, a fillet-to-bonding layer factor (t f /t bl ) of 0.5, a contact factor (A b /A f ) of more than 5. 
     A 4 inch C-Plane sapphire workpiece was provided for conducting a cutting operation. The workpiece was sliced to form 4 wafers using a first sample (S1) representative of an abrasive article of Example 1. Additionally, the workpiece was slice to form 4 wafers using a second sample (S2) representative of an abrasive article of Example 2. The workpiece was sliced under the conditions indicated below in Table 1 below. 
     
       
         
           
               
             
               
                 TABLE 1 
               
               
                   
               
               
                 Input &amp; Testing Conditions 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                   
                 Machine 
                 Takatori K2 
               
               
                   
                 Ingot Material &amp; Size 
                 4″ Sapphire, C-Plane 
               
               
                   
                 # of wafers 
                 4 
               
               
                   
                 Wire speed (m/min) 
                 400 
               
               
                   
                 Wire Tension (N) 
                 30 
               
               
                   
                 Wire usage (M) 
                 140 
               
               
                   
                 Wire guide pitch (mm) 
                 1 
               
               
                   
                 Rocking angle (degrees) 
                 5 
               
               
                   
                 Rocking speed (degrees/min) 
                 500 
               
               
                   
                 Time of Cut (hrs:mins) 
                 10:02 
               
               
                   
                   
               
            
           
         
       
     
     After completing the cutting operation, the quality of the wafers formed from the workpiece was evaluated. The evaluation included a general measure of damage to the wafer by the slicing operation including analysis of total thickness variation (TTV) and surface roughness (Ra) of each of the wafers. As illustrated in Table 2 below, the wafers formed by sample S2 for the sapphire had a thickness variation that was approximately 50% lower (i.e., 50% improvement) than the thickness variation of Sample S1 with comparable Ra. The data demonstrates a remarkable improvement in the quality of wafers formed using sample S2 over sample S1. 
     
       
         
           
               
               
               
             
               
                 TABLE 2 
               
               
                   
               
               
                 Characteristic 
                 Sample S1 
                 Sample S2 
               
               
                   
               
             
            
               
                 TTV 
                 28 ± 1  
                 19 ± 2  
               
               
                 Ra 
                 0.42 ± 0.05 
                 0.38 ± 0.04 
               
               
                   
               
            
           
         
       
     
     The present application represents a departure from the state of the art. Notably, the embodiments herein demonstrate improved and unexpected performance over conventional wire saws. While not wishing to be bound to a particular theory, it is suggested that combination of certain features including designs, processes, materials, and the like may facilitate such improvements. The combination of features can include, but is not limited to, controlled processing conditions including re-flow temperature, filler content, filler size, filler composition, average particle size of the abrasive particles, size distribution of the abrasive particles, content of the abrasive particles, composition of the abrasive particles, thickness of the first layer, composition of the first layer, atmospheric conditions, and a combination thereof, and fillet characteristics including a tacking factor (t fl /t f ), a fillet-to-particle factor (t f /d ab ), a fillet-to-bonding layer factor (t f /t bl ), a contact factor (A b /A f ) or a fillet size variance (V f ). The combination of features can also include, but is not limited to, fillet characteristics including a tacking factor (t fl /t f ) of not greater than about 2, a fillet-to-particle factor (t f /d ab ) of not greater than about 1, a fillet-to-bonding layer factor (t f /t bl ) of not greater than about 1, a contact factor (A b /A f ) of at least about 1 or a combination thereof. Notably, the industry has generally tried to reduce the thickness of underlying layers to reduce the size of fillets. However, quite unexpectedly, and contrary to some conventional approaches, the inventors of the present application have found that certain controlled processing conditions may be utilized to facilitate certain desired fillet characteristics, which may in turn facilitate improved performance in certain abrasive applications. Notably, despite an expectation that larger fillets may facilitate improved holding of abrasive particles, it was surprising found that fillets of certain characteristics can provide improved performance on harder materials. Moreover, without wishing to be tied to a particular theory, it has been offered that certain other fillet characteristics can be tailored to other abrasive applications, and such fillet characteristics can have remarkable affects on the grinding performance of an abrasive article depending upon the intended abrasive application. 
     The above-disclosed subject matter is to be considered illustrative, and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments, which fall within the true scope of the present invention. Thus, to the maximum extent allowed by law, the scope of the present invention is to be determined by the broadest permissible interpretation of the following claims and their equivalents, and shall not be restricted or limited by the foregoing detailed description. 
     The Abstract of the Disclosure is provided to comply with Patent Law and is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description of the Drawings, various features may be grouped together or described in a single embodiment for the purpose of streamlining the disclosure. This disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter may be directed to less than all features of any of the disclosed embodiments. Thus, the following claims are incorporated into the Detailed Description of the Drawings, with each claim standing on its own as defining separately claimed subject matter. 
     Item 1. An abrasive article comprising: a substrate comprising an elongated member; a first layer overlying the substrate; abrasive particles overlying the first layer; fillets connecting the first layer and the abrasive particles; a bonding layer overlying the abrasive particles; and wherein the fillets have a fillet characteristic relative to an abrasive application, the fillet characteristic selected from the group consisting of a tacking factor (tfl/tf), a fillet-to-particle factor (tf/dab), a fillet-to-bonding layer factor (tf/tbl), a contact factor (Ab/Af), a fillet size variance (Vf), and a combination thereof. 
     Item 2. An abrasive article comprising: a substrate comprising an elongated member; a first layer overlying the substrate; abrasive particles overlying the first layer; fillets connecting the first layer and the abrasive particles; a bonding layer overlying the abrasive particles; and wherein the fillets have a fillet characteristic adapted to an abrasive application, the fillet characteristic selected from the group consisting of a tacking factor (tfl/tf), a fillet-to-particle factor (tf/dab), a fillet-to-bonding layer factor (tf/tbl), a contact factor (Ab/Af), a fillet size variance (Vf), and a combination thereof. 
     Item 3. An abrasive article comprising: a substrate comprising an elongated member; a first layer overlying the substrate; abrasive particles overlying the first layer; fillets connecting the first layer and the abrasive particles; and a fillet characteristic comprising a fillet-to-particle factor (tf/dab) for an abrasive application of the abrasive article, wherein tf represents an average maximum thickness of the fillets and dab represents a median particle size of the abrasive particles. 
     Item 4. An abrasive article comprising: a substrate comprising an elongated member; a first layer overlying the substrate; abrasive particles overlying the first layer; fillets connecting the first layer and the abrasive particles; and a fillet characteristic comprising a tacking factor (tfl/tf) for an abrasive application of the abrasive article, wherein to represents an average thickness of the first layer and tf represents an average maximum thickness of the fillets. 
     Item 5. A method of forming an abrasive article comprising: providing a body including abrasive particles overlying a first layer, the first layer overlying a substrate; processing at least the substrate, the first layer, and the abrasive particles according to a controlled processing condition to form an abrasive article having a fillet characteristic relative to an abrasive application, the fillet characteristic selected from the group consisting of a tacking factor (tfl/tf), a fillet-to-particle factor (tf/dab), a fillet-to-bonding layer factor (tf/tbl), a contact factor (Ab/Af), a fillet size variance (Vf), and a combination thereof; and wherein the controlled processing condition is selected from the group consisting of re-flow temperature, filler content, filler size, filler composition, average particle size of the abrasive particles, size distribution of the abrasive particles, content of the abrasive particles, composition of the abrasive particles, thickness of the first layer, composition of the first layer, atmospheric conditions, and a combination thereof. 
     Item 6. The abrasive article and method of any one of items 1, 2, 4, and 5, wherein the tacking factor (tfl/tf) is at least about 0.01, at least about 0.02, at least about 0.03, at least about 0.04, at least about 0.05, at least about 0.1, at least about 0.2, at least about 0.3, at least about 0.4, at least about 0.5, at least about 0.6, at least about 0.7, at least about 0.8, at least about 0.9, at least about 1.0, at least about 1.1, at least about 1.2, at least about 1.3, at least about 1.4, at least about 1.5, at least about 1.6, at least about 1.7, at least about 1.8 and at least about 1.9; and wherein tfl represents an average thickness of the first layer and tf represents an average maximum thickness of the fillets. 
     Item 7. The abrasive article and method of any one of items 1, 2, 4, and 5, wherein the tacking factor (tfl/tf) is not greater than about 2, not greater than about 1.9, not greater than about 1.8, not greater than about 1.7, not greater than about 1.6, not greater than about 1.5, not greater than about 1.4, not greater than about 1.3, not greater than about 1.2, not greater than about 1.1, not greater than about 1, not greater than about 0.9, not greater than about 0.8, not greater than about 0.7, not greater than about 0.6, not greater than about 0.5, not greater than about 0.4, not greater than about 0.3 and not greater than about 0.2, wherein tfl represents an average thickness of the first layer and tf represents an average maximum thickness of the fillets. 
     Item 8. The abrasive article of item 3, further comprising a fillet characteristic comprising a tacking factor (tfl/tf), wherein the tacking factor (tfl/tf) is at least about 0.01, at least about 0.02, at least about 0.03, at least about 0.04, at least about 0.05, at least about 0.1, at least about 0.2, at least about 0.3, at least about 0.4, at least about 0.5, at least about 0.6, at least about 0.7, at least about 0.8, at least about 0.9, at least about 1.0, at least about 1.1, at least about 1.2, at least about 1.3, at least about 1.4, at least about 1.5, at least about 1.6, at least about 1.7, at least about 1.8 and at least about 1.9; and wherein tfl represents an average thickness of the first layer and tf represents an average maximum thickness of the fillets. 
     Item 9. The abrasive article of item 3, further comprising a fillet characteristic comprising a tacking factor (tfl/tf), wherein the tacking factor (tfl/tf) is not greater than about 2, not greater than about 1.9, not greater than about 1.8, not greater than about 1.7, not greater than about 1.6, not greater than about 1.5, not greater than about 1.4, not greater than about 1.3, not greater than about 1.2, not greater than about 1.1, not greater than about 1, not greater than about 0.9, not greater than about 0.8, not greater than about 0.7, not greater than about 0.6, not greater than about 0.5, not greater than about 0.4, not greater than about 0.3 and not greater than about 0.2, wherein tfl represents an average thickness of the first layer and tf represents an average maximum thickness of the fillets. 
     Item 10. The abrasive article and method of any one of items 1, 2, 3, and 5, wherein the fillet characteristic of the fillet-to-particle factor (tf/dab) is at least about 0.01, at least about 0.02, at least about 0.03, at least about 0.04, at least about 0.05, at least about 0.06, at least about, at least about 0.08, at least about 0.1, at least about 0.12, at least about 0.15, at least about 0.2, at least about 0.25, at least about 0.3, at least about 0.35, at least about 0.4, at least about 0.45, at least about 0.5 and at least about 0.5. 
     Item 11. The abrasive article of item 4, further comprising a fillet characteristic comprising a fillet-to-particle factor (tf/dab), wherein the fillet characteristic of the fillet-to-particle factor (tf/dab) is at least about 0.01, at least about 0.02, at least about 0.03, at least about 0.04, at least about 0.05, at least about 0.06, at least about, at least about 0.08, at least about 0.1, at least about 0.12, at least about 0.15, at least about 0.2, at least about 0.25, at least about 0.3, at least about 0.35, at least about 0.4, at least about 0.45, at least about 0.5 and at least about 0.5. 
     Item 12. The abrasive article and method of any one of items 1, 2, 3, and 5, wherein the fillet characteristic of the fillet-to-particle factor (tf/dab) is not greater than about 0.95, not greater than about 0.9, not greater than about 0.85, not greater than about 0.80, not greater than about 0.75, not greater than about 0.7, not greater than about 0.7, not greater than about 0.65 and greater than about 0.6. 
     Item 13. The abrasive article of item 4, further comprising a fillet characteristic comprising a fillet-to-particle factor (tf/dab), wherein the fillet characteristic of the fillet-to-particle factor (tf/dab) wherein the fillet characteristic of the fillet-to-particle factor (tf/dab) is not greater than about 0.95, not greater than about 0.9, not greater than about 0.85, not greater than about 0.80, not greater than about 0.75, not greater than about 0.7, not greater than about 0.7, not greater than about 0.65 and greater than about 0.6. 
     Item 14. The abrasive article and method of any one of items 1, 2, and 5, wherein the contact factor (Ab/Af) is not greater than about 100, not greater than about 95, not greater than about 90, not greater than about 85, not greater than about 80, not greater than about 75, not greater than about 70, not greater than about 65, not greater than about 60, not greater than about 55, not greater than about 50, not greater than about 45, not greater than about 40, not greater than about 35, not greater than about 30, not greater than about 25, not greater than about 20, not greater than about 15 and not greater than about 10, wherein Ab represents an average percentage of a surface area of the abrasive particles in contact with the bonding layer, and Af represents an average percentage of the surface area of the abrasive particles in contact with the fillets. 
     Item 15. The abrasive article of any one of items 3 and 4, further comprising a fillet characteristic comprising a contact factor (Ab/Af), wherein the contact factor (Ab/Af) is not greater than about 100, not greater than about 95, not greater than about 90, not greater than about 85, not greater than about 80, not greater than about 75, not greater than about 70, not greater than about 65, not greater than about 60, not greater than about 55, not greater than about 50, not greater than about 45, not greater than about 40, not greater than about 35, not greater than about 30, not greater than about 25, not greater than about 20, not greater than about 15 and not greater than about 10, wherein Ab represents an average percentage of a surface area of the abrasive particles in contact with the bonding layer, and Af represents an average percentage of the surface area of the abrasive particles in contact with the fillets. 
     Item 16. The abrasive article and method of any one of items 1, 2, and 5, wherein the contact factor (Ab/Af) is at least about 0.01, at least about 0.02, at least about 0.05, at least about 0.08, at least about 0.1, at least about 0.15, at least about 0.2, at least about 0.25, at least about 0.3, at least about 0.35, at least about 0.4, at least about 0.45, at least about 0.5, at least about 0.55, at least about 0.6, at least about 0.65, at least about 0.7, at least about 0.75, at least about 0.8, at least about 0.85, at least about 0.9 and at least about 0.95, wherein Ab represents an average percentage of a surface area of the abrasive particles in contact with the bonding layer, and Af represents an average percentage of the surface area of the abrasive particles in contact with the fillets. 
     Item 17. The abrasive article of any one of items 3 and 4, further comprising a fillet characteristic comprising a contact factor (Ab/Af), wherein the contact factor (Ab/Af) is at least about 0.01, at least about 0.02, at least about 0.05, at least about 0.08, at least about 0.1, at least about 0.15, at least about 0.2, at least about 0.25, at least about 0.3, at least about 0.35, at least about 0.4, at least about 0.45, at least about 0.5, at least about 0.55, at least about 0.6, at least about 0.65, at least about 0.7, at least about 0.75, at least about 0.8, at least about 0.85, at least about 0.9 and at least about 0.95, wherein Ab represents an average percentage of a surface area of the abrasive particles in contact with the bonding layer, and Af represents an average percentage of the surface area of the abrasive particles in contact with the fillets. 
     Item 18. The abrasive article and method of any one of items 1, 2, and 5, wherein the fillet-to-bonding layer factor (tf/tbl) is at least about 0.01, at least about 0.02, at least about 0.05, at least about 0.1, at least about 0.15, at least about 0.2, at least about 0.25, at least about 0.3, at least about 0.35, at least about 0.4, at least about 0.45 and at least about 0.5, wherein tbl represents an average thickness of the bonding layer and tf represents an average maximum thickness of the fillets. 
     Item 19. The abrasive article of any one of items 3 and 4, further comprising a fillet characteristic comprising a fillet-to-bonding layer factor (tf/tbl), wherein the fillet-to-bonding layer factor (tf/tbl) is at least about 0.01, at least about 0.02, at least about 0.05, at least about 0.1, at least about 0.15, at least about 0.2, at least about 0.25, at least about 0.3, at least about 0.35, at least about 0.4, at least about 0.45 and at least about 0.5, wherein tbl represents an average thickness of the bonding layer and tf represents an average maximum thickness of the fillets. 
     Item 20. The abrasive article and method of any one of items 1, 2, and 5, wherein the fillet-to-bonding layer factor (tf/tbl) is not greater than about 100 not greater than about 80, not greater than about 60, not greater than about 40, not greater than about 20, not greater than about 10, not greater than about 5, not greater than about 4, not greater than about 3.5, not greater than about 3, not greater than about 2.8, not greater than about 2.6, not greater than about 2.4, not greater than about 2.2, not greater than about 2, not greater than about 1.9, not greater than about 1.8, not greater than about 1.7, not greater than about 1.6, not greater than about 1.5, not greater than about 1.4, not greater than about 1.3, not greater than about 1.2 and not greater than about 1.1, wherein tbl represents an average thickness of the bonding layer and tf represents an average maximum thickness of the fillets. 
     Item 21. The abrasive article of any one of items 3 and 4, further comprising a fillet characteristic comprising a fillet-to-bonding layer factor (tf/tbl), wherein the fillet-to-bonding layer factor (tf/tbl) is not greater than about 100 not greater than about 80, not greater than about 60, not greater than about 40, not greater than about 20, not greater than about 10, not greater than about 5, not greater than about 4, not greater than about 3.5, not greater than about 3, not greater than about 2.8, not greater than about 2.6, not greater than about 2.4, not greater than about 2.2, not greater than about 2, not greater than about 1.9, not greater than about 1.8, not greater than about 1.7, not greater than about 1.6, not greater than about 1.5, not greater than about 1.4, not greater than about 1.3, not greater than about 1.2 and not greater than about 1.1, wherein tbl represents an average thickness of the bonding layer and tf represents an average maximum thickness of the fillets. 
     Item 22. The abrasive article and method of any one of items 1, 2, and 5, wherein the fillet size variance (Vf) is not greater than about 95%, not greater than about 93%, not greater than about 90%, not greater than about 88%, not greater than about 85%, not greater than about 83%, not greater than about 80%, not greater than about 78%, not greater than about 75%, not greater than about 73%, not greater than about 70%, not greater than about 68%, not greater than about 65%, not greater than about 63%, not greater than about 60%, not greater than about 58%, not greater than about 55%, not greater than about 53%, not greater than about 50%, not greater than about 48%, not greater than about 45%, not greater than about 43%, not greater than about 40%, not greater than about 30%, not greater than about 20% and not greater than about 10% based on the equation [(Fmax−tf/Fmax]×100%, wherein Fmax represents a greatest value of fillet thickness of a sample and tf represents the average maximum thickness of the fillets of a sample. 
     Item 23. The abrasive article of any one of items 3 and 4, further comprising a fillet characteristic comprising a fillet size variance (VI), wherein the fillet size variance (VI) is not greater than about 95%, not greater than about 93%, not greater than about 90%, not greater than about 88%, not greater than about 85%, not greater than about 83%, not greater than about 80%, not greater than about 78%, not greater than about 75%, not greater than about 73%, not greater than about 70%, not greater than about 68%, not greater than about 65%, not greater than about 63%, not greater than about 60%, not greater than about 58%, not greater than about 55%, not greater than about 53%, not greater than about 50%, not greater than about 48%, not greater than about 45%, not greater than about 43%, not greater than about 40%, not greater than about 30%, not greater than about 20% and not greater than about 10% based on the equation [(Fmax−tf)/Fmax]×100%, wherein Fmax represents a greatest value of fillet thickness of a sample and tf represents the average maximum thickness of the fillets of a sample. 
     Item 24. The abrasive article and method of any one of items 1, 2, and 5, wherein the fillet size variance (Vf) is at least about 2%, at least about 5%, at least about 10%, at least about 20%, at least about 30%, at least about 40% and at least about 50% based on the equation [(Fmax−tf/Fmax]×100%, wherein Fmax represents a greatest value of fillet thickness of a sample and tf represents the average maximum thickness of the fillets of a sample. 
     Item 25. The abrasive article of any one of items 3 and 4, further comprising a fillet characteristic comprising a fillet size variance (Vf), wherein the fillet size variance (Vf) is at least about 2%, at least about 5%, at least about 10%, at least about 20%, at least about 30%, at least about 40% and at least about 50% based on the equation [(Fmax−tf)/Fmax]×100%, wherein Fmax represents a greatest value of fillet thickness of a sample and tf represents the average maximum thickness of the fillets of a sample. 
     Item 26. The abrasive article and method of any one of items 1, 2, 3, 4, and 5, wherein the fillets comprise a composition that is substantially the same as a composition of the first layer, wherein the fillets have a composition that is essentially the same as a composition of the first layer, wherein the fillets comprise a composition having a difference in elemental composition of not greater than about 5 mol % for any element compared to a composition of the first layer. 
     Item 27. The abrasive article and method of any one of items 1, 2, 3, 4, and 5, wherein the fillets have a composition that is substantially different compared to a composition of the first layer, wherein the fillets have a composition that includes at least one element different than an element of the first layer, wherein the fillets have a composition having a difference in elemental composition of at least about 5 mol % for any element compared to a composition of the first layer. 
     Item 28. The abrasive article and method of any one of items 1, 2, 3, 4, and 5, wherein the fillets comprise an active bonding material, wherein the active bonding material comprises a material selected from the group consisting of borides, oxides, nitrides, carbides, oxynitrides, oxyborides, oxycarbides, and a combination thereof, wherein the fillets comprise titanium, wherein the fillets comprise titanium carbide. 
     Item 29. The abrasive article and method of any one of items 1, 2, 3, 4, and 5, wherein the fillets comprise a metal, wherein the fillets comprise a metal alloy, wherein the fillets comprise an elemental metal, wherein the fillets comprise a transition metal element, wherein the fillets comprise tin, wherein the fillets comprise copper, wherein the fillets comprise nickel, wherein the fillets comprise solder, wherein the fillets comprise a mixture of tin and copper. 
     Item 30. The abrasive article and method of any one of items 1, 2, 3, 4, and 5, wherein the fillets comprise a mixture of a composition of the first layer and an active bonding material, wherein the fillets comprise at least two discrete phases of material including a first phase and a second phase, wherein the first phase is preferentially located closer to a surface of the abrasive particles as compared to the second phase, wherein the fillets comprises at least three discrete phases of material including a first phase, a second phase, and a third phase. 
     Item 31. The abrasive article and method of any one of items 1, 2, 3, 4, and 5, wherein the fillets extend from the first layer, wherein the fillets are integral with the first layer, wherein the fillets form an amalgamate with the first layer. 
     Item 32. The abrasive article and method of any one of items 1, 2, 3, 4, and 5, further comprising a combination of at least two fillet characteristics from the group consisting of tacking factor (tfl/tf), a fillet-to-particle factor (tf/dab), a fillet-to-bonding layer factor (tf/tbl), a contact factor (Ab/Af), a fillet size variance (Vf). 
     Item 33. The abrasive article and method of any one of items 1, 2, 3, 4, and 5, wherein the abrasive application is based upon at least one parameter selected from the group consisting of a workpiece hardness, a workpiece size, a workpiece composition, abrasive article life, abrasive particle retention strength, cutting force and workpiece quality. 
     Item 34. The abrasive article and method of any one of items 1, 2, 3, 4, and 5, further comprising a filler in the first layer distinct from the abrasive particles, wherein the filler is distinct from the abrasive particles based on at least one filler criteria selected from the group consisting of average particle size, composition, content, concentration, distribution, and a combination thereof. 
     Item 35. The abrasive article and method of item 34, wherein the abrasive particles comprises an average particle size (P1) and the filler comprises a filler average particle size (F1), and wherein the average particle size is greater than the filler average particle size, wherein the average particle size is at least about 5% different than the filler average particle size based on the equation ((P1−F1)/P1)×100%, at least about 10% different, at least about 20% different, at least about 30% different, and not greater than about 99% different. 
     Item 36. The abrasive article and method of item 34, wherein the filler comprises an average particle size of not greater than about 500 microns, not greater than about 300 microns, not greater than about 200 microns, not greater than about 150 microns, not greater than about 100 microns, not greater than about 80 microns, not greater than about 50 microns, not greater than about 30 microns, not greater than about 20 microns, not greater than about 15 microns, not greater than about 12 microns, not greater than about 10 microns, not greater than about 8 microns, and wherein the filler comprises an average particle size of at least about 0.01 microns. 
     Item 37. The abrasive article and method of item 34, wherein the filler comprises a material selected from the group consisting of an inorganic material, an organic material, a polymer, a synthetic material, a natural material, and a combination thereof, wherein the filler comprises a material selected from the group consisting of a thermoplastic, a thermoset, a resin, a ceramic, a glass, a metal, a metal alloy, a metal coated particle, a substantially spherical bead, a hollow body, an elongated body, a fiber, and a combination thereof, wherein the filler comprises a material selected from the group consisting of an oxide, a carbide, a nitride, a boride, diamond, a carbon-based material, cubic boron nitride, and a combination thereof, wherein the filler comprises a Vickers hardness of at least about 0.1 GPa, at least about 1 GPa, such as at least about 3 GPa, wherein the filler comprises a Vickers hardness not greater than about 200 GPa, not greater than about 150 GPa, not greater than about 100 GPa. 
     Item 38. The abrasive article and method of item 34, wherein the abrasive particles comprise an average hardness (Hap) and the filler comprises a filler average hardness (Hf), and wherein the average hardness (Hap) is greater than the filler average hardness (Hf), wherein the average hardness is at least about 5% different than the filler average hardness based on the equation ((Hap−Hf)/Hap)×100%, at least about 10% different, at least about 20% different, at least about 30% different, and not greater than about 99% different. 
     Item 39. The abrasive article and method of item 34, wherein the filler comprises a filler composition distinct from an abrasive particle composition, wherein the filler composition is different from the abrasive particle composition by at least 5 wt % of at least one element within the filler composition and the abrasive particle composition. 
     Item 40. The abrasive article and method of item 34, wherein the abrasive particles are present in an abrasive particle content and the filler is present in a filler content, wherein the abrasive article includes an abrasive particle content greater than a filler content, wherein the filler content is greater than the abrasive particle content, wherein the abrasive particle content is substantially the same as the filler content, further comprising a particle count ratio (Cap:Cf) of abrasive particle content (Cap) to filler content (Cf) of not greater than about 100:1, not greater than about 50:1, not greater than about 20:1, not greater than about 10:1, not greater than about 5:1, not greater than about 2:1, and approximately 1:1, and wherein the particle count ratio (Cap:Cf) is at least about 2:1, at least about 5:1, at least about 10:1, at least about 20:1, at least about 50:1, at least about 100:1. 
     Item 41. The abrasive article and method of item 34, wherein the filler has a greater wetting affinity for a composition of the first layer as compared to a wetting affinity of the abrasive particles relative to the composition of the first layer. 
     Item 42. The method of item 5, wherein processing according to the controlled processing condition includes heating the substrate, the first layer, and the abrasive particles to a re-flow temperature, wherein heating comprises selecting a re-flow temperature and a viscosity and controlling the wetting of the first layer on the abrasive particles, wherein heating comprises selecting a re-flow temperature corresponding to a predetermined viscosity to control the wetting of the first layer on the abrasive particles and controlling the average maximum thickness of the fillets. 
     Item 43. The method of item 42, wherein the re-flow temperature is less than a melting temperature of the first layer, wherein the re-flow temperature is different than the melting temperature by at least about 0.5% based on the equation [(Tm−Tr)/Tm]×100%, wherein Tm represents the melting temperature and Tr represents the re-flow temperature, wherein the re-flow temperature is different than the melting temperature by at least about 1%, at least about 2%, at least about 3%, at least about 4%, at least about 5%, at least about 8%, at least about 10%, at least about 12%, at least about 15%, at least about 20%, at least about 30%, at least about 40%. 
     Item 44. The method of item 5, wherein processing according to the controlled processing condition includes changing a viscosity of the first layer and controlling the wetting of the abrasive particles by the first layer, wherein processing according to the controlled processing condition includes increasing a viscosity of the first layer and controlling the amount of wetting of the abrasive particles by the first layer. 
     Item 45. The method of item 5, wherein processing according to the controlled processing condition includes providing a filler to control the wetting of the first layer on the abrasive particles, wherein processing according to the controlled processing condition comprises selecting at least one of a filler composition, a filler size, and a filler content to control the wetting of the first layer on the abrasive particles, wherein processing according to the controlled processing condition includes providing a filler to control the average maximum thickness of the fillets. 
     Item 46. The method of item 5, wherein processing according to the controlled processing condition includes providing an atmospheric condition selected from the group consisting of a reducing atmosphere, an oxidizing atmosphere, an inert atmosphere, an atmosphere consisting essentially of one element, and a combination thereof. 
     Item 47. The abrasive article and method of any one of items 1, 2, 3, 4, and 5, wherein the substrate comprises a material selected from the group consisting of metal, metal alloys, ceramic, glass, and a combination thereof, wherein the substrate comprises a metal comprising a transition metal element, wherein the substrate comprises steel, wherein the substrate has an elongated body, the substrate comprises an elongated body having an aspect ratio of length:width of at least about 10:1, wherein the substrate comprises an elongated body having an aspect ratio of length:width of at least about 10000:1. 
     Item 48. The abrasive article and method of any one of items 1, 2, 3, 4, and 5, wherein the substrate comprises an average length of at least about 50 m, at least about 100 m, at least about 500 m, at least about 1000 m, wherein the substrate comprises an average width of not greater than about 1 mm, not greater than about 0.8 mm, not greater than about 0.5 mm, wherein the core of the substrate comprises an average width of at least about 0.01 mm, wherein the substrate consists essentially of a wire, wherein the core of the substrate comprises a plurality of filaments braided together. 
     Item 49. The abrasive article and method of any one of items 1, 2, 3, 4, and 5, further comprising a barrier layer in direct contact with a peripheral surface of the substrate, wherein the barrier layer is disposed between the peripheral surface of the substrate and the first layer, wherein the barrier layer comprises an inorganic material, wherein the barrier layer comprises a metal or metal alloy, wherein the barrier layer comprises a transition metal element, wherein the barrier layer comprises a material different from the first layer, where in the barrier layer consists of copper, wherein the barrier layer consists essentially of nickel, wherein the barrier layer comprises a non-alloyed material. 
     Item 50. The abrasive article and method of any one of items 1, 2, 3, 4, and 5, wherein the first layer is configured to be a tacking layer and provisionally hold the abrasive particles in place during processing, wherein the first layer is in direct contact with a surface of the substrate. 
     Item 51. The abrasive article and method of any one of items 1, 2, 3, 4, and 5, wherein the first layer comprises a material selected from the group of materials consisting of metal, metal alloys, metal matrix composites, and a combination thereof, wherein the first layer comprises a transition metal element, wherein the first layer comprises an alloy of transition metal elements, wherein the first layer comprises tin, wherein the first layer comprises a metal selected from the group of metals consisting of lead, silver, copper, zinc, tin, indium, titanium, molybdenum, chromium, iron, manganese, cobalt, niobium, tantalum, tungsten, palladium, platinum, gold, ruthenium, and a combination thereof, wherein the first layer comprises a metal alloy of tin and lead, wherein the first layer comprises tin, wherein the first layer consists essentially of tin. 
     Item 52. The abrasive article and method of any one of items 1, 2, 3, 4, and 5, wherein the first layer comprises a solder material, wherein the first layer has a melting point of not greater than about 450° C., not greater than about 400° C., not greater than about 375° C., not greater than about 350° C., and at least about 100° C. 
     Item 53. The abrasive article and method of any one of items 1, 2, 3, 4, and 5, wherein the first layer comprises an average thickness of not greater than about 80% of an average particle size of the abrasive particles, not greater than about 70%, not greater than about 40%, and wherein the first layer comprises an average thickness of at least about 2%, at least about 5%, at least about 6%, at least about 7%, at least about 8%, at least about 9%, at least about 10%, at least about 11%, at least about 12%, at least about 13%. 
     Item 54. The abrasive article and method of any one of items 1, 2, 3, 4, and 5, wherein the abrasive particles comprises a material selected from the group of materials consisting of oxides, carbides, nitrides, borides, oxynitrides, oxyborides, diamond, and a combination thereof, wherein the abrasive particles comprises a superabrasive material, wherein the abrasive particles comprises diamond, the abrasive particles consists essentially of diamond, wherein the abrasive particles comprises a material having a Vickers hardness of at least about 10 GPa. 
     Item 55. The abrasive article and method of any one of items 1, 2, 3, 4, and 5, wherein the abrasive particles include a first type of abrasive particle and a second type of abrasive particle different than the first type of abrasive particle, wherein the first type of abrasive particle is different than the second type of abrasive particle based on at least one particle characteristics selected from the group consisting of hardness, friability, toughness, particle shape, crystalline structure, average particle size, composition, particle coating, grit size distribution, and a combination thereof. 
     Item 56. The abrasive article and method of item 55, wherein the first type of abrasive particle comprises a first average particle size (P1) and the second type of abrasive particle comprises a second average particle size (P2), and wherein the first average particle size is greater than the second average particle size, wherein the first average particle size is at least about 5% different than the second average particle size based on the equation ((P1−P2)/P1)×100%, at least about 10% different, at least about 20% different, at least about 30% different, and not greater than about 99% different. 
     Item 57. The abrasive article of any one of items 1 and 2, wherein the bonding layer directly contacts at least a portion of the first layer, wherein the bonding layer directly contacts a portion of the abrasive particles, wherein the bonding layer directly contacts a particle film layer on the abrasive particles, wherein the bonding layer overlies a majority of an external surface of the substrate and an external surface of the abrasive particles. 
     Item 58. The abrasive article and method of any one of items 3, 4, and 5, further comprising a bonding layer overlying the abrasive particles, wherein the bonding layer directly contacts at least a portion of the first layer, wherein the bonding layer directly contacts a portion of the abrasive particles, wherein the bonding layer directly contacts a particle film layer on the abrasive particles, wherein the bonding layer overlies a majority of an external surface of the substrate and an external surface of the abrasive particles. 
     Item 59. The abrasive article and method of item 58, wherein the bonding layer comprises a material selected from the group of materials consisting of metals, metal alloys, cements, ceramics, composites, and a combination thereof, wherein the bonding layer comprises a transition metal element, wherein the bonding layer comprises an alloy of transition metal elements, wherein the bonding layer comprises a metal selected from the group of metals consisting of lead, silver, copper, zinc, tin, titanium, molybdenum, chromium, iron, manganese, cobalt, niobium, tantalum, tungsten, palladium, platinum, gold, ruthenium, and a combination thereof, wherein the bonding layer comprises nickel, wherein the bonding layer consists essentially of nickel. 
     Item 60. The abrasive article and method of item 58, wherein the bonding layer comprises an average thickness of at least about 5% of an average particle size of the abrasive particles, wherein the bonding layer comprises an average thickness of not greater than about 100% of an average particle size of the abrasive particles. 
     Item 61. The abrasive article and method of item 58, wherein the bonding layer comprise an average thickness of at least about 1 micron, at least about 2 microns, at least about 3 microns, not greater than about 60 microns, not greater than about 50 microns, not greater than about 40 microns, not greater than about 30 microns. 
     Item 62. The abrasive article and method of any one of items 1 and 2, wherein the bonding layer comprises a material selected from the group of materials consisting of metals, metal alloys, cements, ceramics, composites, and a combination thereof, wherein the bonding layer comprises a transition metal element, wherein the bonding layer comprises an alloy of transition metal elements, wherein the bonding layer comprises a metal selected from the group of metals consisting of lead, silver, copper, zinc, tin, titanium, molybdenum, chromium, iron, manganese, cobalt, niobium, tantalum, tungsten, palladium, platinum, gold, ruthenium, and a combination thereof, wherein the bonding layer comprises nickel, wherein the bonding layer consists essentially of nickel. 
     Item 63. The abrasive article and method of any one of items 1 and 2, wherein the bonding layer comprises an average thickness of at least about 5% of an average particle size of the abrasive particles, wherein the bonding layer comprises an average thickness of not greater than about 100% of an average particle size of the abrasive particles. 
     Item 64. The abrasive article and method of any one of items 1 and 2, wherein the bonding layer comprise an average thickness of at least about 1 micron, at least about 2 microns, at least about 3 microns, not greater than about Item 60 microns, not greater than about 50 microns, not greater than about 40 microns, not greater than about 30 microns. 
     Item 65. The abrasive article and method of any one of items 1, 2, 3, 4, and 5, further comprising a coating layer overlying the substrate, wherein the coating layer overlies the bonding layer, wherein the coating layer comprises a material selected from the group of materials consisting of metals, metal alloys, cements, ceramics, organics and a combination thereof. 
     Item 66. The abrasive article and method of any one of items 1, 2, 3, 4, and 5, further comprising an abrasive particle concentration of the abrasive particles particle of at least about 5 particles per mm of substrate, at least about 7 particles per mm of substrate, at least about 10 particles per mm of substrate, at least about 20 particles per mm of substrate, at least about 30 particles per mm of substrate, and not greater than about 800 particles per mm of substrate. 
     Item 67. The method of item 5, wherein providing a body comprises: providing a substrate; forming the first layer using a deposition process selected from the group consisting of spraying, gravity coating, dipping, die coating, electrostatic coating, and a combination thereof; placing the abrasive particles on the first layer in contact with the first layer to bind the first type of abrasive particle to the first layer, wherein placing the first type of abrasive particle on the first layer comprises a deposition process selected from the group consisting of spraying, gravity coating, dipping, die coating, electrostatic coating, and a combination thereof; wherein placing the abrasive particles on the first layer includes placing an additional layer comprising a flux material overlying the first layer; and further comprising heating the first layer to a temperature of not greater than about 450° C. 
     Item 68. An abrasive article comprising: a substrate comprising an elongated member; a first layer overlying the substrate; abrasive particles overlying the first layer; fillets connecting the first layer and the abrasive particles; and a tacking factor (t fl /t f ) of not greater than about 1.5, wherein t fl  represents an average thickness of the first layer and t f  represents an average thickness of the fillets. 
     Item 69. An abrasive article comprising: a substrate comprising an elongated member; a first layer overlying the substrate; abrasive particles overlying the first layer; fillets connecting the first layer and the abrasive particles; and a fillet-to-particle factor (t f /d ab ) of not greater than about 0.33, wherein t f  represents an average thickness of the fillets and d ab  represents an average particle size of the abrasive particles. 
     An abrasive article comprising: a substrate comprising an elongated member; a first layer overlying the substrate; abrasive particles overlying the first layer; fillets connecting the first layer and the abrasive particles; and a bonding layer overlying the abrasive particles, wherein a majority of the abrasive particles have an undercut region defining a portion of the bonding layer extending under a portion of the abrasive particle between the abrasive particle and the first layer. 
     Item 71. An abrasive article comprising: a substrate comprising an elongated member; a first layer overlying the substrate; abrasive particles overlying the first layer; fillets connecting the first layer and the abrasive particles; a bonding layer overlying the abrasive particles; and wherein the abrasive particles have a contact factor (A b /A f ) of at least about 1, wherein A b  represents an average percentage of a surface area of the abrasive particles in contact with the bonding layer, and A f  represents an average percentage of the surface area of the abrasive particles in content with the fillets. 
     Item 72. An abrasive article comprising: a substrate comprising an elongated member; a first layer overlying the substrate; abrasive particles overlying the first layer; fillets connecting the first layer and the abrasive particles; a bonding layer overlying the abrasive particles; at least one fillet characteristic selected from the group consisting of a tacking factor (t fl /t f ) of not greater than about 1.5, a fillet-to-particle factor (t f /d ab ) of not greater than about 0.33, a fillet-to-bonding layer factor (t f /t bl ) of not greater than about 100, a contact factor (A b /A f ) of at least about 1, a fillet size variance (V f ) of not greater than 60% or a combination thereof; and wherein the first layer comprises an average thickness of at least about 6% of an average particle size of the abrasive particles. 
     Item 73. A method of forming an abrasive article comprising: providing a body including abrasive particles overlying a first layer, the first layer overlying a substrate; processing at least the substrate, the first layer, and the abrasive particles according to a controlled processing condition to form an abrasive article having a fillet characteristic selected from the group consisting of a tacking factor (t fl /t f ) of not greater than about 1.5, a fillet-to-particle factor (t f /d ab ) of not greater than about 0.33, a fillet-to-bonding layer factor (t f /t bl ) of not greater than about 100, a contact factor (A b /A f ) of at least about 1, a fillet size variance (V f ) of not greater than 60% or a combination thereof; and wherein the controlled processing condition is selected from the group consisting of re-flow temperature, filler content, filler size, filler composition, average particle size of the abrasive particles, size distribution of the abrasive particles, content of the abrasive particles, composition of the abrasive particles, thickness of the first layer, composition of the first layer, and a combination thereof. 
     Item 74. The abrasive article and method of any one of items 68, 72, and 73, wherein the tacking factor (t fl /t f ) is not greater than about 1.5, not greater than about 1.4, not greater than about 1.3, not greater than about 1.2, not greater than about 1.1, not greater than about 1, not greater than about 0.99, not greater than about 0.97, not greater than about 0.95, not greater than about 0.92, not greater than about 0.9, not greater than about 0.85, not greater than about 0.8, not greater than about 0.75, not greater than about 0.7, not greater than about 0.65, not greater than about 0.6, not greater than about 0.55 and not greater than about 0.51. 
     Item 75. The abrasive article of any one of items 69, 70 and 71, further comprising a tacking factor (t fl /t f ) of not greater than about 1.5, not greater than about 1.4, not greater than about 1.3, not greater than about 1.2, not greater than about 1.1, not greater than about 1, not greater than about 0.99, not greater than about 0.97, not greater than about 0.95, not greater than about 0.92, not greater than about 0.9, not greater than about 0.85, not greater than about 0.8, not greater than about 0.75, not greater than about 0.7, not greater than about 0.65, not greater than about 0.6, not greater than about 0.55 and not greater than about 0.51, wherein t fl  represents an average thickness of the first layer and t f  represents an average maximum thickness of the fillets. 
     Item 76. The abrasive article and method of any one of items 68, 72, and 73, wherein the tacking factor (t fl /t f ) is at least about 0.5, at least about 0.55, at least about 0.6, at least about 0.65, at least about 0.7, at least about 0.75, at least about 0.8, at least about 0.85, at least about 0.9, at least about 0.92, at least about 0.95, at least about 0.97, at least about 0.99, at least about 1, at least about 1.1, at least about 1.2, at least about 1.3 and at least about 1.4. 
     Item 77. The abrasive article of any one of items 69, 70 and 71, further comprising a tacking factor (t fl /t f ) of at least about 0.5, at least about 0.55, at least about 0.6, at least about 0.65, at least about 0.7, at least about 0.75, at least about 0.8, at least about 0.85, at least about 0.9, at least about 0.92, at least about 0.95, at least about 0.97, at least about 0.99, at least about 1, at least about 1.1, at least about 1.2, at least about 1.3 and at least about 1.4, wherein t fl  represents an average thickness of the first layer and t f  represents an average maximum thickness of the fillets. 
     Item 78. The abrasive article and method of any one of items 69, 72 and 73, wherein the fillet-to-particle factor (t f /d ab ) is not greater than about 0.33, not greater than about 0.31, not greater than about 0.3, not greater than about 0.27, not greater than about 0.25, not greater than about 0.23, not greater than about 0.2, not greater than about 0.17, not greater than about 0.15, not greater than about 0.13, not greater than about 0.1, not greater than about 0.07 and not greater than about 0.06. 
     Item 79. The abrasive article of any one of items 68, 70 and 71, further comprising a fillet-to-particle factor (t f /d ab ) of not greater than about 0.33, not greater than about 0.31, not greater than about 0.3, not greater than about 0.27, not greater than about 0.25, not greater than about 0.23, not greater than about 0.2, not greater than about 0.17, not greater than about 0.15, not greater than about 0.13, not greater than about 0.1, not greater than about 0.07 and not greater than about 0.06, wherein t f  represents an average maximum thickness of the fillets and d ab  represents and an average particle size of the abrasive particles. 
     Item 80. The abrasive article and method of any one of items 69, 72 and 73, wherein the fillet-to-particle factor (t f /d ab ) is at least about 0.05, at least about 0.07, at least about 0.1, at least about 0.12, at least about 0.14, at least about 0.16, at least about 0.18, at least about 0.20, at least about 0.24, at least about 0.26, at least about 0.28, at least about 0.30 and at least about 0.32. 
     Item 81. The abrasive article of any one of items 68, 70 and 71, further comprising a fillet-to-particle factor (t f /d ab ) of at least about 0.05, at least about 0.07, at least about 0.1, at least about 0.12, at least about 0.14, at least about 0.16, at least about 0.18, at least about 0.20, at least about 0.24, at least about 0.26, at least about 0.28, at least about 0.30 and at least about 0.32, wherein t f  represents an average maximum thickness of the fillets and d ab  represents and an average particle size of the abrasive particles. 
     Item 82. The abrasive article and method of any one of items 72 and 73, wherein the fillet-to-bonding layer factor (t f /t bl ) is not greater than about 100, not greater than about 90, not greater than about 80, not greater than about 70, not greater than about 60, not greater than about 50, not greater than about 40, not greater than about 35, not greater than about 30, not greater than about 28, not greater than about 26, not greater than about 24, not greater than about 22, not greater than about 20, not greater than about 18, not greater than about 16, not greater than about 14, not greater than about 12 and not greater than about 11, wherein t f  represents an average maximum thickness of the fillets and t bl  represents and an average thickness of the bonding layer. 
     Item 83. The abrasive article of any one of items 68, 69, 70 and 71, further comprising a fillet-to-bonding layer factor (t f /t bl ) of not greater than about 100, not greater than about 90, not greater than about 80, not greater than about 70, not greater than about 60, not greater than about 50, not greater than about 40, not greater than about 35, not greater than about 30, not greater than about 28, not greater than about 26, not greater than about 24, not greater than about 22, not greater than about 20, not greater than about 18, not greater than about 16, not greater than about 14, not greater than about 12 and not greater than about 11, wherein t f  represents an average maximum thickness of the fillets and t bl  represents and an average thickness of the bonding layer. 
     Item 84. The abrasive article and method of any one of items 72 and 73, wherein the fillet-to-bonding layer factor (t f /t bl ) is at least about 10, at least about 12, at least about 14, at least about 16, at least about 18, at least about 20, at least about 22, at least about 24, at least about 26, at least about 28, at least about 30, at least about 35, at least about 40, at least about 45, at least about 50, at least about 60, at least about 70, at least about 80, at least about 90 and at least about 95, wherein t f  represents an average maximum thickness of the fillets and t bl  represents and an average thickness of the bonding layer. 
     Item 85. The abrasive article of any one of items 68, 69, 70 and 71, further comprising a fillet-to-bonding layer factor (t f /t bl ) of at least about 10, at least about 12, at least about 14, at least about 16, at least about 18, at least about 20, at least about 22, at least about 24, at least about 26, at least about 28, at least about 30, at least about 35, at least about 40, at least about 45, at least about 50, at least about 60, at least about 70, at least about 80, at least about 90 and at least about 95, wherein t f  represents an average maximum thickness of the fillets and t bl  represents and an average thickness of the bonding layer, wherein t f  represents an average maximum thickness of the fillets and t bl  represents and an average thickness of the bonding layer. 
     Item 86. The abrasive article and method of any one of items 71, 72 and 73, wherein the contact factor (A b /A f ) is at least about 1.0, at least about 1.2, at least about 1.4, at least about 1.5, at least about 1.6, at least about 1.7, at least about 1.8, at least about 1.9, at least about 2, at least about 2.2, at least about 2.4, at least about 2.6, at least about 2.8, at least about 3, at least about 3.5, at least about 4, at least about 5, at least about 6, at least about 7, at least about 8 and at least about 9, wherein A b  represents an average percentage of a surface area of the abrasive particles in contact with the bonding layer, and A f  represents an average percentage of the surface area of the abrasive particles in contact with the fillets. 
     Item 87. The abrasive article of any one of items 68, 69 and 70, further comprising a contact factor (A b /A f ) of at least about 1.0, at least about 1.2, at least about 1.4, at least about 1.5, at least about 1.6, at least about 1.7, at least about 1.8, at least about 1.9, at least about 2, at least about 2.2, at least about 2.4, at least about 2.6, at least about 2.8, at least about 3, at least about 3.5, at least about 4, at least about 5, at least about 6, at least about 7, at least about 8 and at least about 9, wherein A b  represents an average percentage of a surface area of the abrasive particles in contact with the bonding layer, and A f  represents an average percentage of the surface area of the abrasive particles in contact with the fillets. 
     Item 88. The abrasive article and method of any one of items 71, 72 and 73, wherein the contact factor (A b /A f ) is not greater than about 10, not greater than about 9, not greater than about 8, not greater than about 7, not greater than about 6, not greater than about 5, not greater than about 4, not greater than about 3.5, not greater than about 3, not greater than about 2.8, not greater than about 2.6, not greater than about 2.4, not greater than about 2.3, not greater than about 2.2, not greater than about 2, not greater than about 1.9, not greater than about 1.8, not greater than about 1.7, not greater than about 1.6, not greater than about 1.5, not greater than about 1.4, not greater than about 1.3, not greater than about 1.2 and not greater than about 1.1, wherein A b  represents an average percentage of a surface area of the abrasive particles in contact with the bonding layer, and A f  represents an average percentage of the surface area of the abrasive particles in contact with the fillets. 
     Item 89. The abrasive article of any one of items 68, 69 and 70, further comprising a contact factor (A b /A f ) of not greater than about 10, not greater than about 9, not greater than about 8, not greater than about 7, not greater than about 6, not greater than about 5, not greater than about 4, not greater than about 3.5, not greater than about 3, not greater than about 2.8, not greater than about 2.6, not greater than about 2.4, not greater than about 2.3, not greater than about 2.2, not greater than about 2, not greater than about 1.9, not greater than about 1.8, not greater than about 1.7, not greater than about 1.6, not greater than about 1.5, not greater than about 1.4, not greater than about 1.3, not greater than about 1.2 and not greater than about 1.1, wherein A b  represents an average percentage of a surface area of the abrasive particles in contact with the bonding layer, and A f  represents an average percentage of the surface area of the abrasive particles in contact with the fillets. 
     Item 90. The abrasive article and method of any one of items 68, 69, 70, 71, 72 and 73, further comprising a fillet size variance (V f ) of not greater than about 60%, such as, not greater than about 58%, not greater than about 55%, not greater than about 53%, not greater than about 50%, not greater than about 48%, not greater than about 45%, not greater than about 43%, not greater than about 40%, not greater than about 30%, not greater than about 20%, not greater than about 10%, not greater than about 8%, not greater than about 6%, not greater than about 4% or even not greater than about 3%. 
     Item 91. The abrasive article and method of any one of items 68, 69, 70, 71, 72 and 73, further comprising a fillet size variance (V f ) of at least about 2%, at least about 5%, at least about 10%, at least about 20%, at least about 30%, at least about 40% or even at least about 50%. 
     Item 92. The abrasive article and method of any one of items 68, 69, 70, 71, 72 and 73, wherein the fillets comprise a composition that is substantially the same as a composition of the first layer, wherein the fillets have a composition that is essentially the same as a composition of the first layer, wherein the fillets comprise a composition having a difference in elemental composition of not greater than about 5 wt. % for any element compared to a composition of the first layer. 
     Item 93. The abrasive article and method of any one of items 68, 69, 70, 71, 72 and 73, wherein the fillets have a composition that is substantially different compared to a composition of the first layer, wherein the fillets have a composition that includes at least one element different than an element of the first layer, wherein the fillets have a composition having a difference in elemental composition of at least about 5 wt. % for any element compared to a composition of the first layer. 
     Item 94. The abrasive article and method of any one of items 68, 69, 70, 71, 72 and 73, wherein the fillets comprise an active bonding material, wherein the active bonding material comprises a material selected from the group consisting of borides, oxides, nitrides, carbides, oxynitrides, oxyborides, oxycarbides, and a combination thereof, wherein the fillets comprise titanium, wherein the fillets comprise titanium carbide. 
     Item 95. The abrasive article and method of any one of items 68, 69, 70, 71, 72 and 73, wherein the fillets comprise a metal, wherein the fillets comprise a metal alloy, wherein the fillets comprise an elemental metal, wherein the fillets comprise a transition metal element, wherein the fillets comprise tin, wherein the fillets comprise copper, wherein the fillets comprise nickel, wherein the fillets comprise solder, wherein the fillets comprise a mixture of tin and copper. 
     Item 96. The abrasive article and method of any one of items 68, 69, 70, 71, 72 and 73, wherein the fillets comprise a mixture of a composition of the first layer and an active bonding material, wherein the fillets comprise at least two discrete phases of material including a first phase and a second phase, wherein the first phase is preferentially located closer to a surface of the abrasive particles as compared to the second phase, wherein the fillets comprises at least three discrete phases of material including a first phase, a second phase, and a third phase. 
     Item 97. The abrasive article and method of any one of items 68, 69, 70, 71, 72 and 73, wherein the fillets extend from the first layer, wherein the fillets are integral with the first layer, wherein the fillets form an amalgamate with the first layer. 
     Item 98. The abrasive article and method of any one of items 68, 69, 70, 71, 72 and 73, wherein further comprising a combination of at least two fillet characteristics from the group consisting of tacking factor (t fl /t f ), a fillet-to-particle factor (t f /d ab ), a fillet-to-bonding layer factor (t f /t bl ), and a contact factor (A b /A f ). 
     Item 99. The abrasive article and method of any one of items 68, 69, 70, 71, 72 and 73, further comprising a filler in the first layer distinct from the abrasive particles, wherein the filler is distinct from the abrasive particles based on at least one filler criteria selected from the group consisting of average particle size, composition, content, concentration, distribution, and a combination thereof. 
     Item 100. The abrasive article of item 99, wherein the abrasive particles comprises an average particle size (P1) and the filler comprises a filler average particle size (F1), and wherein the average particle size is greater than the filler average particle size, wherein the average particle size is at least about 5% different than the filler average particle size based on the equation ((P1−F1)/P1)×100%, at least about 10% different, at least about 20% different, at least about 30% different, and not greater than about 99% different. 
     Item 101. The abrasive article of item 99, wherein the filler comprises an average particle size of not greater than about 500 microns, not greater than about 300 microns, not greater than about 200 microns, not greater than about 150 microns, not greater than about 100 microns, not greater than about 80 microns, not greater than about 50 microns, not greater than about 30 microns, not greater than about 20 microns, not greater than about 15 microns, not greater than about 12 microns, not greater than about 10 microns, not greater than about 8 microns, and wherein the filler comprises an average particle size of at least about 0.01 microns. 
     Item 102. The abrasive article of item 99, wherein the filler comprises a material selected from the group consisting of an inorganic material, an organic material, a polymer, a synthetic material, a natural material, and a combination thereof, wherein the filler comprises a material selected from the group consisting of a thermoplastic, a thermoset, a resin, a ceramic, a glass, a metal, a metal alloy, a metal coated particle, a substantially spherical bead, a hollow body, an elongated body, a fiber, and a combination thereof, wherein the filler comprises a material selected from the group consisting of an oxide, a carbide, a nitride, a boride, diamond, a carbon-based material, cubic boron nitride, and a combination thereof, wherein the filler comprises a Vickers hardness of at least about 0.1 GPa, at least about 1 GPa, such as at least about 3 GPa, wherein the filler comprises a Vickers hardness not greater than about 200 GPa, not greater than about 150 GPa, not greater than about 100 GPa. 
     Item 103. The abrasive article of item 99, wherein the abrasive particles comprise an average hardness (Hap) and the filler comprises a filler average hardness (Hf), and wherein the average hardness (Hap) is greater than the filler average hardness (Hf), wherein the average hardness is at least about 5% different than the filler average hardness based on the equation ((Hap−Hf)/Hap)×100%, at least about 10% different, at least about 20% different, at least about 30% different, and not greater than about 99% different. 
     Item 104. The abrasive article of item 99, wherein the filler comprises a filler composition distinct from an abrasive particle composition, wherein the filler composition is different from the abrasive particle composition by at least 5 wt. % of at least one element within the filler composition and the abrasive particle composition. 
     Item 105. The abrasive article of item 99, wherein the abrasive particles are present in an abrasive particle content and the filler is present in a filler content, wherein the abrasive article includes an abrasive particle content greater than a filler content, wherein the filler content is greater than the abrasive particle content, wherein the abrasive particle content is substantially the same as the filler content, further comprising a particle count ratio (Cap:Cf) of abrasive particle content (Cap) to filler content (Cf) of not greater than about 100:1, not greater than about 50:1, not greater than about 20:1, not greater than about 10:1, not greater than about 5:1, not greater than about 2:1, and approximately 1:1, and wherein the particle count ratio (Cap:Cf) is at least about 2:1, at least about 5:1, at least about 10:1, at least about 20:1, at least about 50:1, at least about 100:1. 
     Item 106. The abrasive article of item 99, wherein the filler has a greater wetting affinity for a composition of the first layer as compared to a wetting affinity of the abrasive particles relative to the composition of the first layer. 
     Item 107. The method of item 73, wherein processing according to the controlled processing condition includes heating the substrate, the first layer, and the abrasive particles to a re-flow temperature, wherein heating comprises selecting a re-flow temperature and a viscosity of the first layer and controlling the wetting of the first layer on the abrasive particles, wherein heating comprises selecting a re-flow temperature corresponding to a predetermined viscosity of the first layer at the re-flow temperature to control the wetting of the first layer on the abrasive particles and controlling the average maximum thickness of the fillets. 
     Item 108. The method of item 107, wherein the re-flow temperature is less than a melting temperature of the first layer, wherein the re-flow temperature is different than the melting temperature by at least about 0.5% based on the equation [(Tm−Tr)/Tm]×100%, wherein Tm represents the melting temperature and Tr represents the re-flow temperature, wherein the re-flow temperature is different than the melting temperature by at least about 1%, at least about 2%, at least about 3%, at least about 4%, at least about 5%, at least about 8%, at least about 10%, at least about 12%, at least about 15%, at least about 20%, at least about 30%, at least about 40%. 
     Item 109. The method of item 107, wherein the re-flow temperature is not greater than about 450° C., not greater than about 440° C., not greater than about 430° C., not greater than about 420° C., not greater than about 410° C., not greater than about 400° C., not greater than about 390° C., not greater than about 380° C., not greater than about 370° C., not greater than about 360° C., not greater than about 350° C., not greater than about 340° C., not greater than about 330° C., not greater than about 320° C., not greater than about 310° C., not greater than about 300° C., and wherein the re-flow temperature is at least about 100° C., at least about 120° C., at least about 150° C., at least about 180° C., at least about 200° C., at least about 220° C. 
     Item 110. The method of item 73, wherein processing according to the controlled processing condition includes changing a viscosity of the first layer and controlling the wetting of the abrasive particles by the first layer, wherein processing according to the controlled processing condition includes increasing a viscosity of the first layer and controlling the amount of wetting of the abrasive particles by the first layer. 
     Item 111. The method of item 73, wherein processing according to the controlled processing condition includes providing a filler to control the wetting of the first layer on the abrasive particles, wherein processing according to the controlled processing condition comprises selecting at least one of a filler composition, a filler size, and a filler content to control the wetting of the first layer on the abrasive particles, wherein processing according to the controlled processing condition includes providing a filler to control the average maximum thickness of the fillets. 
     Item 112. The method of item 73, wherein processing according to the controlled processing condition includes providing an atmospheric condition selected from the group consisting of a reducing atmosphere, an oxidizing atmosphere, an inert atmosphere, an atmosphere consisting essentially of one element, and a combination thereof. 
     Item 113. The abrasive article and method of any one of items 68, 69, 70, 71, 72 and 73, wherein the substrate comprises a material selected from the group consisting of metal, metal alloys, ceramic, glass, and a combination thereof, wherein the substrate comprises a metal comprising a transition metal element, wherein the substrate comprises steel, wherein the substrate has an elongated body, the substrate comprises an elongated body having an aspect ratio of length:width of at least about 10:1, wherein the substrate comprises an elongated body having an aspect ratio of length:width of at least about 10000:1. 
     Item 114. The abrasive article and method of any one of items 68, 69, 70, 71, 72 and 73, wherein the substrate comprises an average length of at least about 50 m, at least about 100 m, at least about 500 m, at least about 1000 m, wherein the substrate comprises an average width of not greater than about 1 mm, not greater than about 0.8 mm, not greater than about 0.5 mm, wherein the core of the substrate comprises an average width of at least about 0.01 mm, wherein the substrate consists essentially of a wire, wherein the core of the substrate comprises a plurality of filaments braided together. 
     Item 115. The abrasive article and method of any one of items 68, 69, 70, 71, 72 and 73, further comprising a barrier layer in direct contact with a peripheral surface of the substrate, wherein the barrier layer is disposed between the peripheral surface of the substrate and the first layer, wherein the barrier layer comprises an inorganic material, wherein the barrier layer comprises a metal or metal alloy, wherein the barrier layer comprises a transition metal element, wherein the barrier layer comprises a material different from the first layer, where in the barrier layer consists of copper, wherein the barrier layer consists essentially of nickel, wherein the barrier layer comprises a non-alloyed material. 
     Item 116. The abrasive article and method of any one of items 68, 69, 70, 71, 72 and 73, wherein the first layer is configured to be a tacking layer and provisionally hold the abrasive particles in place during processing, wherein the first layer is in direct contact with a surface of the substrate. 
     Item 117. The abrasive article and method of any one of items 68, 69, 70, 71, 72 and 73, wherein the first layer comprises a material selected from the group of materials consisting of metal, metal alloys, metal matrix composites, and a combination thereof, wherein the first layer comprises a transition metal element, wherein the first layer comprises an alloy of transition metal elements, wherein the first layer comprises tin, wherein the first layer comprises a metal selected from the group of metals consisting of lead, silver, copper, zinc, tin, indium, titanium, molybdenum, chromium, iron, manganese, cobalt, niobium, tantalum, tungsten, palladium, platinum, gold, ruthenium, and a combination thereof, wherein the first layer comprises a metal alloy of tin and lead, wherein the first layer comprises tin, wherein the first layer consists essentially of tin. 
     Item 118. The abrasive article and method of any one of items 68, 69, 70, 71, 72 and 73, wherein the first layer comprises a solder material, wherein the first layer has a melting point of not greater than about 450° C., not greater than about 400° C., not greater than about 375° C., not greater than about 350° C., and at least about 100° C. 
     Item 119. The abrasive article and method of any one of items 68, 69, 70, 71, 72 and 73, wherein the first layer comprises an average thickness of not greater than about 80% of an average particle size of the abrasive particles, not greater than about 70%, not greater than about 40%, and wherein the first layer comprises an average thickness of at least about 7%, at least about 8%, at least about 9%, at least about 10%, at least about 11%, at least about 12%, at least about 13%. 
     Item 120. The abrasive article and method of any one of items 68, 69, 70, 71, 72 and 73, wherein the abrasive particles comprises a material selected from the group of materials consisting of oxides, carbides, nitrides, borides, oxynitrides, oxyborides, diamond, and a combination thereof, wherein the abrasive particles comprises a superabrasive material, wherein the abrasive particles comprises diamond, the abrasive particles consists essentially of diamond, wherein the abrasive particles comprises a material having a Vickers hardness of at least about 10 GPa. 
     Item 121. The abrasive article and method of any one of items 68, 69, 70, 71, 72 and 73, wherein the abrasive particles include a first type of abrasive particle and a second type of abrasive particle different than the first type of abrasive particle, wherein the first type of abrasive particle is different than the second type of abrasive particle based on at least one particle characteristics selected from the group consisting of hardness, friability, toughness, particle shape, crystalline structure, average particle size, composition, particle coating, grit size distribution, and a combination thereof. 
     Item 122. The abrasive article and method of item 121, wherein the first type of abrasive particle comprises a first average particle size (P1) and the second type of abrasive particle comprises a second average particle size (P2), and wherein the first average particle size is greater than the second average particle size, wherein the first average particle size is at least about 5% different than the second average particle size based on the equation ((P1−P2)/P1)×100%, at least about 10% different, at least about 20% different, at least about 30% different, and not greater than about 99% different. 
     Item 123. The abrasive article of any one of items 70, 71 and 72, wherein the bonding layer directly contacts at least a portion of the first layer, wherein the bonding layer directly contacts a portion of the abrasive particles, wherein the bonding layer directly contacts a particle film layer on the abrasive particles, wherein the bonding layer overlies a majority of an external surface of the substrate and an external surface of the abrasive particles. 
     Item 124. The abrasive article and method of any one of items 68, 69 and 73, further comprising a bonding layer overlying the abrasive particles, wherein the bonding layer directly contacts at least a portion of the first layer, wherein the bonding layer directly contacts a portion of the abrasive particles, wherein the bonding layer directly contacts a particle film layer on the abrasive particles, wherein the bonding layer overlies a majority of an external surface of the substrate and an external surface of the abrasive particles. 
     Item 125. The abrasive article and method of item 124, wherein the bonding layer comprises a material selected from the group of materials consisting of metals, metal alloys, cements, ceramics, composites, and a combination thereof, wherein the bonding layer comprises a transition metal element, wherein the bonding layer comprises an alloy of transition metal elements, wherein the bonding layer comprises a metal selected from the group of metals consisting of lead, silver, copper, zinc, tin, titanium, molybdenum, chromium, iron, manganese, cobalt, niobium, tantalum, tungsten, palladium, platinum, gold, ruthenium, and a combination thereof, wherein the bonding layer comprises nickel, wherein the bonding layer consists essentially of nickel. 
     Item 126. The abrasive article and method of item 124, wherein the bonding layer comprises an average thickness of at least about 5% of an average particle size of the abrasive particles, wherein the bonding layer comprises an average thickness of not greater than about 100% of an average particle size of the abrasive particles. 
     Item 127. The abrasive article and method of item 124, wherein the bonding layer comprise an average thickness of at least about 1 micron, at least about 2 microns, at least about 3 microns, not greater than about 60 microns, not greater than about 50 microns, not greater than about 40 microns, not greater than about 30 microns. 
     Item 128. The abrasive article of any one of items 70, 71 and 72, wherein the bonding layer comprises a material selected from the group of materials consisting of metals, metal alloys, cements, ceramics, composites, and a combination thereof, wherein the bonding layer comprises a transition metal element, wherein the bonding layer comprises an alloy of transition metal elements, wherein the bonding layer comprises a metal selected from the group of metals consisting of lead, silver, copper, zinc, tin, titanium, molybdenum, chromium, iron, manganese, cobalt, niobium, tantalum, tungsten, palladium, platinum, gold, ruthenium, and a combination thereof, wherein the bonding layer comprises nickel, wherein the bonding layer consists essentially of nickel. 
     Item 129. The abrasive article of any one of items 70, 71 and 72, wherein the bonding layer comprises an average thickness of at least about 5% of an average particle size of the abrasive particles, wherein the bonding layer comprises an average thickness of not greater than about 100% of an average particle size of the abrasive particles. 
     Item 130. The abrasive article of any one of items 70, 71 and 72, wherein the bonding layer comprise an average thickness of at least about 1 micron, at least about 2 microns, at least about 3 microns, not greater than about 60 microns, not greater than about 50 microns, not greater than about 40 microns, not greater than about 30 microns. 
     Item 131. The abrasive article and method of any one of items 68, 69, 70, 71, 72 and 73, further comprising a coating layer overlying the substrate, wherein the coating layer overlies the bonding layer, wherein the coating layer comprises a material selected from the group of materials consisting of metals, metal alloys, cements, ceramics, organics and a combination thereof. 
     Item 132. The abrasive article and method of any one of items 68, 69, 70, 71, 72 and 73, wherein further comprising an abrasive particle concentration of the abrasive particles particle of at least about 5 particles per mm of substrate, at least about 7 particles per mm of substrate, at least about 10 particles per mm of substrate, at least about 20 particles per mm of substrate, at least about 30 particles per mm of substrate, and not greater than about 800 particles per mm of substrate. 
     Item 133. The method of item 73, wherein providing a body comprises: providing a substrate; forming the first layer using a deposition process selected from the group consisting of spraying, gravity coating, dipping, die coating, electrostatic coating, and a combination thereof; placing the abrasive particles on the first layer in contact with the first layer to bind the first type of abrasive particle to the first layer, wherein placing the first type of abrasive particle on the first layer comprises a deposition process selected from the group consisting of spraying, gravity coating, dipping, die coating, electrostatic coating, and a combination thereof; wherein placing the abrasive particles on the first layer includes placing an additional layer comprising a flux material overlying the first layer; and further comprising heating the first layer to a temperature of not greater than about 450° C. 
     Item 134. The abrasive article and method of any one of items 68, 69, 70, 71, 72 and 73, wherein at least a portion of the abrasive particles are spaced apart from an upper surface of the substrate, wherein a majority of the abrasive particles are spaced apart from an upper surface of the substrate. 
     Item 135. The abrasive article and method of any one of items 68, 69, 70, 71, 72 and 73, wherein at least about 55% of the abrasive particles have an undercut region, at least about 60%, at least about 70%, at least about 80%, at least about 90%, at least about 95%.