Patent Abstract:
A method of making glass is provided. The method comprises preparing a dispersion of a nano-material. A slurry of a glass matrix material is prepared. The nano-dispersion is mixed with the matrix slurry to form a nano-dispersion/slurry mixture. The nano-dispersion/slurry mixture is dried. The nano-dispersion/slurry mixture is pressed into a final manufacture comprising a molecular structure including the nano-material bonded within and uniformly distributed throughout the molecular structure. The manufacture comprises an increased fracture toughness compared with a conventional manufacture produced without bonding the nano-material within the molecular structure. The nano-material has a size on the order of tens of nanometers. The matrix material has a size on the order of several micrometers. Five percent of the nano-dispersion/slurry mixture comprises the nano-material dispersion. Sintering is performed on the final form using a sintering process following the pressing step. The sintering process includes a hot isostatic pressing process.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Patent Application Ser. No. 61/284,329, filed Dec. 15, 2009 and entitled “MATERIALS PROCESSING,” which is hereby incorporated herein by reference in its entirety as if set forth herein. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to the field of materials science. More particularly, the present invention relates to glass manufactures and a novel method of making 
     BACKGROUND 
     In many applications, glass is utilized because of the desired properties such as transparency and light transmission. Many household products are made of glass and glass has many decorative functions. Glass is also used widely in buildings and automobiles just to name a few more applications. Glass can be reinforced with some kind of particulate matter. Composite glass is desirable since in addition to their high hardness the composite can also possess a greater fracture toughness, which includes the ability to resist fracture. Present methods used to produce composite glass are costly, inefficient and complicated. 
     Accordingly, it is desirable to create an efficient and inexpensive method to produce glass having improve material characteristics, and especially fracture toughness. 
     SUMMARY OF THE INVENTION 
     Other features of the present invention will become apparent from consideration of the following description taken in conjunction with the accompanying drawings. 
     A first aspect of the present invention is for a method of making glass is provided. The method comprises preparing a dispersion of a nano-material. A slurry of a glass matrix material is prepared. The nano-dispersion is mixed with the matrix slurry to form a nano-dispersion/slurry mixture. In one embodiment, the mixing includes pouring the matrix slurry into the nano-dispersion while agitating. Alternative, the mixing includes pouring the nano-dispersion into the matrix slurry while agitating. The nano-dispersion/slurry mixture is dried. The nano-dispersion/slurry mixture is pressed into a final manufacture comprising a molecular structure including the nano-material bonded within and uniformly distributed throughout the molecular structure. The manufacture comprises an increased fracture toughness compared with a conventional manufacture produced without bonding the nano-material within the molecular structure. 
     The method includes providing the nano-material with a size on the order of tens of nanometers before the dispersion preparing step. A micron sized matrix material is provided on the order of several micrometers before the slurry preparing step. One percent of the nano-dispersion/slurry mixture comprises the nano-material dispersion. Alternatively, 0.5-10.0 percent of the nano-dispersion/slurry mixture comprises the nano-material dispersion. In yet another alternative, 0.5-20.0 percent of the nano-dispersion/slurry mixture comprises the nano-material dispersion. Sintering is performed on the final form using a sintering process following the pressing step. The sintering process includes a hot isostatic pressing process. The manufacture includes the nano-material bonded at triple points of the molecular structure. The drying of the nano-dispersion/slurry mixture includes a spray drying process. 
     Other features of the present invention will become apparent from consideration of the following description taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The novel features of the invention are set forth in the appended claims. However, for purposes of explanation, several embodiments of the invention are set forth in the following figures. 
         FIG. 1  illustrates a plot of fracture toughness of a glass compared with a metal in accordance with an embodiment of the invention. 
         FIG. 2  illustrates a partial of a manufacture with improved fracture toughness in accordance with an embodiment of the invention. 
         FIG. 3  illustrates a method of making a glass with improved fracture toughness in accordance with an embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     In the following description, numerous details and alternatives are set forth for the purpose of explanation. However, one of ordinary skill in the art will realize that the invention can be practiced without the use of these specific details. In other instances, well-known structures and devices are shown in block diagram form in order not to obscure the description of the invention with unnecessary detail. 
     Turning to  FIG. 1 , a plot  10  of fracture toughness of a glass compared with a metal is shown in accordance with an embodiment of the invention. Fracture toughness is a term in the field of material science that describes the characteristic of a material that has a crack to resist fracture. More specifically, fracture toughness describes a resistance of a material to a brittle fracture when a crack is present in the material. Brittle fracture occurs when the material exhibits no apparent plastic deformation prior to the fracture, in contrast to a ductile fracture, which is when the material exhibits extensive plastic deformation prior to the fracture. A glass will exhibit a low fracture toughness  12 A while a metal will exhibit a significantly higher fracture toughness  12 B. A novel method of the invention as described below produces a glass having an increased fracture toughness  12 A′. 
     Hardness is a quality also shown in the plot of  FIG. 1 . Hardness is a term that describes the characteristic of a solid material to resist deformation. A metal will exhibit a low hardness  14 A while a glass will exhibit a significantly higher hardness  14 B. 
     Turning to  FIG. 2 , a partial of a manufacture  200  with improved fracture toughness is shown in accordance with an embodiment of the invention. The manufacture  200  comprises a composite of a glass matrix material  201  and nanoparticles or nano-material  206 . The glass material  201  can comprise any a number of suitable glass materials depending on a particular application. In an exemplary embodiment the glass material  201  comprises a material from a group of silicon dioxide composites. A person of skill will appreciate the many possible oxides capable of combining with silicon dioxide to form the glass material. In one embodiment, the silicon dioxide composite can comprise silicon dioxide combined with a mixture of sodium carbonate, and either calcium carbonate or calcium oxide. In an alternative embodiment, the silicon dioxide composite can comprise silicon dioxide combined with boric oxide. In yet another embodiment, the silicon dioxide composite can comprise silicon dioxide combined with lead oxide. 
     Alternatively, the glass material  201  can comprise pure Silica or silicon dioxide (SiO2). In still another embodiment, the glass material can comprise a metallic glass. Examples of metallic glass alloys include alloys based on zirconium or palladium. The method as described in detail below produces the manufacture  200  in a final form that includes a “granular” or a molecular structure  204  having an amorphous disordered structure propagated throughout the manufacture  200 . The molecular structure  204  comprises an average molecular boundary distance or diameter  208  of one to several micrometers. Preferably, the average molecular diameter  208  equals approximately one micrometer. 
     The nano-material  206  can comprise any a number of suitable materials that are non-miscible with the glass material  201  depending on a particular application. In an exemplary embodiment, the nano-material  206  can comprise a metallic material or a nano-metal. Examples of suitable metallic materials can include copper, silver and gold. A person of skill can appreciate that other metallic materials can also be suitable for the nano-material  206 . Alternatively, the suitable metallic material can comprise a metallic compound. In an alternative embodiment, the nano-material  206  comprises a material from a group of non-oxide ceramics. Examples of suitable non-oxide ceramics can include titanium carbide or titanium diboride. In yet another embodiment, the nano-material  206  can comprise an oxide ceramic material that is non-miscible with the glass matrix material  201 , for example, alumina and zirconia. A person of skill will appreciate an effect of the nano-material  206  on a refractive index and a transparent quality of the manufacture  200 . Thus the nano-material  206  can be chosen such that refractive indexes of the nano-material  206  and the glass matrix material  201  are equal. 
     The novel method of the invention produces the manufacture  200  having nanoparticles  206  bonded within the molecular structure  204 . The nanoparticles  206  are bonded within the molecular structure  204  of the glass material  201 . A surface  202  of the manufacture  200  reveals that the nanoparticles  206  are substantially uniformly distributed throughout the molecular structure  204 . Additionally, the manufacture  200  includes the nanoparticles  206  substantially uniformly distributed throughout a three dimensional mass of the manufacture  200 . A novel result of the method includes the nanoparticles  206  substantially uniformly distributed where three or more interfaces intersect or at triple points  210  of the glass material  201 . Preferably, the nanoparticles  206  comprise an average diameter suitable for bonding within the molecular structure  204  of the glass material  201 . In an exemplary embodiment, the nanoparticles  206  have an average diameter of approximately 1 to 40 nm. Preferably, the average diameter of the nanoparticles  206  is 20 nm+/−10 nm. 
     Turning to  FIG. 3 , a method is shown for making a glass with improved fracture toughness in accordance with an embodiment of the invention. The method step  310  comprises providing a quantity of nanoparticles  206  which are suitable for bonding with glass material. The nanoparticles  206  preferably comprise an average diameter of 5-15 nm+/−4 nm. The nanoparticles  206  can be in the form of a powder. Any suitable method of providing the nanoparticles  206  known to a person of skill can be used. Such methods can include attrition of some kind. For example, ball milling or feeding micron sized material into a plasma process such as described and claimed in the co-owned and co-pending application Ser. No. 11/110,341, filed Apr. 19, 2005, and titled “High Throughput Discovery of Materials Through Vapor Phase Synthesis,” which is incorporated herein by reference. The method step  320  comprises providing a quantity of glass matrix material  201 . The matrix material  201  comprises an average grain diameter of 500-600 nm. Alternatively, the matrix material  201  can comprise an average grain diameter of one micrometer. The matrix material  201  typically comprises a powered substance. The matrix material  201  can comprise a form of miniature beads or spheres. 
     The method step  330  comprises preparing a dispersion  332  of the nanoparticles  206  of the step  310 . The dispersion  332  comprises a suspension of the nanoparticles  206  in a suitable liquid or suspension liquid. The nanoparticles  206  can comprise a nano-metal with an average diameter of 5-15 nm+/−4 nm. The nanoparticles  206  can comprise 0.5-20% of the dispersion  332 . Alternatively, the nanoparticles  206  can comprise 0.5-10% of the dispersion  332 . In another alternative, the nanoparticles  206  can comprise approximately 1.0% of the dispersion  332 . In an exemplary embodiment, the suspension liquid comprises water and a surfactant. The surfactant can comprise ten percent of the suspension liquid. Any suitable surfactant can be used. Such surfactants are manufactured by Lubrizol Corporation. In an alternative embodiment, a wetting agent can also be included in the suspension liquid. The wetting agent can be five percent relative to water of the suspension liquid. Alternatively, the suspension liquid comprises an alcohol. Other liquids known to a person of skill can also be utilized. The dispersion  332  comprises a pH suitable for best mixing results with a slurry  342  of the step  340 . In an exemplary embodiment, the pH of the dispersion  332  comprises a base. In another embodiment, the base pH comprises a 7.5 pH. 
     A feature of the method of the invention contemplates that the dispersion  332  comprises a substantially uniform distribution of the nanoparticles  206  within the liquid. The uniform dispersion  332  facilitates a uniform diameter of the nanoparticles  206  in the suspension and prevents a forming of large aggregations of the nanoparticles  206 . A high concentration of large aggregations of nanoparticles  206  inhibit the desired uniform distribution of the nanoparticles  206  within the molecular structure  204  of the manufacture  200 . 
     The method step  340  comprises preparing a slurry  342  of the glass matrix material  201  of the step  320 . The slurry  342  preferably comprises a viscous suspension of the glass matrix material  201  in a suitable liquid. The glass matrix material  201  can comprise SiO2 with an average diameter of 500-600 nm. The glass matrix material  201  can comprise 50% of the slurry  342 . In an exemplary embodiment, the suspension liquid comprises water. Other liquids known to a person of skill can also be utilized. The slurry  342  can include various additives or binders that facilitate a mixing, a drying, a melting and a sintering step described later below. The slurry  342  comprises a pH suitable for best mixing results with the dispersion  332 . In an exemplary embodiment, the pH of the slurry  342  comprises a base. In one embodiment, the base pH comprises an 8.0-9.0 pH. In another embodiment, the base pH comprises an 11.0 pH. 
     The method step  350  comprises mixing the nano-dispersion  332  with the matrix slurry  342  to form a nano-dispersion/slurry mixture  352 . The mixing of the nano-dispersion/slurry mixture  352  can comprise suitable agitation methods known to a person of skill. The mixing of the nano-dispersion/slurry mixture  352  produces a dispersion of the nanoparticles  206  within the matrix slurry so that the nanoparticles  206  are uniformly distributed throughout the nano-dispersion/slurry mixture  352 . In an exemplary embodiment, the mixing comprises slowly pouring the slurry  342  into the dispersion  332 . Preferably, the nano-dispersion/slurry mixture  352  is sonicated during the pouring of the slurry  342 . A sonicating horn can be dipped in the dispersion  332  while pouring the slurry  342 . A stir bar can optionally be placed in the dispersion  332  during the pouring of the slurry  342 . The stir bar can be used to agitate the nano-dispersion/slurry mixture  352  while pouring the slurry  342 . The percentage of the nano-dispersion/slurry mixture  352  that comprises the nano-dispersion  332  can vary between 0.5% to 20%. Alternatively, the nano-dispersion/slurry mixture  352  comprises 0.5% to 10% of the nano-dispersion  332 . In another alternative, the nano-dispersion/slurry mixture  352  comprises 0.5% to 3.0% of the nano-dispersion  332 . 
     In an alternative embodiment, the mixing comprises slowly pouring the dispersion  332  into the slurry  342 . The nano-dispersion/slurry mixture  352  is sonicated during the pouring of the dispersion  332 . A sonicating horn can be dipped in the slurry  342  while pouring the dispersion  332 . A stir bar can be placed in the slurry  342  during the pouring of the dispersion  332 . The stir bar can be used to agitate the nano-dispersion/slurry mixture  352  while pouring the dispersion  332 . Other mixing techniques known to a person of skill the art can be substituted for the mixing and agitation described above. 
     In one embodiment, the various additives or binders that facilitate mixing, drying and sintering can be added to the slurry  342  before the mixing step of step  350 . Alternatively, the additives or binders can be added to the nano-dispersion/slurry mixture  352  after the mixing step  350 . 
     The method step  360  comprises drying the nano-dispersion/slurry mixture  352 . In an exemplary embodiment, a spray drying process is utilized to dry the nano-dispersion/slurry mixture  352 . The spray drying process comprises loading a spray gun and spraying the nano-dispersion/slurry mixture  352  into a closed compartment, for example, a glove box. The nano-dispersion/slurry mixture  352  is sprayed within the compartment and then allowed to dry. As the drying process proceeds, appreciable amounts of the liquid of the nano-dispersion/slurry mixture  352  evaporate to result in a powdered form or a premanufacture  368 . In an alternative embodiment, the method step  360  comprises a freeze drying process. Freeze drying comprises placing the nano-dispersion/slurry mixture  352  into a freeze dryer and allowing the liquid of the nano-dispersion/slurry mixture  352  to evaporate until what results comprises the powdered form or the premanufacture  368 . 
     The process step  365  comprises the premanufacture  368  which is the result of the drying step  360 . The premanufacture  368  comprises the nanoparticles  206  uniformly distributed throughout the glass matrix material  201 . 
     The method step  370  comprises a process to make the powdered premanufacture  368  a melt. Making the powdered premanufacture  368  a melt comprises placing the powdered premanufacture  368  of the method step  365  into a mold and pressing the powdered premanufacture  368  to form a molded premanufacture  372 . Heat is also applied to the molded premanufacture  372  sufficient to liquify and integrate the nanoparticles  206  with the matrix material  201 . A person of skill will choose any suitable method of heating the molded premanufacture  372  to cause liquidisation. The molded premanufacture  372  is allowed to cool. 
     The method step  380  comprises a process of sintering the molded premanufacture  372 . The sintering process comprises using any of a variety of sintering processes. In an exemplary embodiment, the sintering process comprises a hot isostatic pressing (HIP) process. The hot isostatic pressing comprises placing the molded premanufacture  372  into a HIP furnace where the molded premanufacture  372  is heated under pressure. The HIP process facilitates a removal of porosity within the molded premanufacture  372 . In an alternative embodiment, a liquid phase sintering process as practiced in the art can be used for the method step  380 . In yet another embodiment, a simple hot pressing process as practiced in the art can be used. 
     Referring back to  FIG. 2 , a result of the method  300  comprises the manufacture  200  with improved fracture toughness in accordance with an embodiment of the invention. The manufacture  200  comprises a composite of a glass material  201  and nanoparticles or nano-material  206 . The novel feature of the method  300  produces the manufacture  200  comprising the nanoparticles  206  uniformly distributed throughout the glass material  201 . 
     While the invention has been described with reference to numerous specific details, one of ordinary skill in the art will recognize that the invention can be embodied in other specific forms without departing from the spirit of the invention. Thus, one of ordinary skill in the art will understand that the invention is not to be limited by the foregoing illustrative details, but rather is to be defined by the appended claims.

Technology Classification (CPC): 8