Patent Publication Number: US-9409231-B2

Title: Method of casting damped part with insert

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional application of U.S. application Ser. No. 12/174,223 filed Jul. 16, 2008 and claims the benefit of U.S. application Ser. No. 13/113,619 filed May 23, 2011, U.S. application Ser. No. 13/113,636 filed May 23, 2011 and Provisional Application No. 60/950,906 filed Jul. 20, 2007. 
    
    
     TECHNICAL FIELD 
     The field to which the disclosure generally relates includes a part with an insert providing frictional damping and method of manufacturing thereof. 
     BACKGROUND 
     Parts subjected to vibration may produce unwanted or undesirable vibrations. Similarly, a part or component may be set into motion at an undesirable frequency and/or amplitude and for a prolonged period. For example, parts such as brake rotors, brackets, pulleys, brake drums, transmission housings, gears, and other parts may contribute to noise that gets transmitted to the passenger compartment of a vehicle. In an effort to reduce the generation of this noise and thereby its transmission into the passenger compartment, a variety of techniques have been employed, including the use of polymer coatings on engine parts, sound absorbing barriers, and laminated panels having viscoelastic layers. The undesirable vibrations in parts or components may occur in a variety of other products including, but not limited to, sporting equipment, household appliances, manufacturing equipment such as lathes, milling/grinding/drilling machines, earth moving equipment, other nonautomotive components, and components that are subject to dynamic loads and vibration. These components can be manufactured through a variety of means including casting, machining, forging, die-casting, etc. 
     SUMMARY OF EXEMPLARY EMBODIMENTS OF THE INVENTION 
     One embodiment of the invention provides a method including positioning an insert in a vertical mold including a first mold portion and a second mold portion; and casting a material including a metal around at least a portion of the insert. 
     Other exemplary embodiments of the invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while disclosing exemplary embodiments of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary embodiments of the present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
         FIG. 1  illustrates a product according to one embodiment of the invention; 
         FIG. 2A  illustrates a process according to one embodiment of the invention; 
         FIG. 2B  illustrates a process according to one embodiment of the invention; 
         FIG. 3  illustrates a process according to one embodiment of the invention; 
         FIG. 4  illustrates a process according to one embodiment of the invention; 
         FIG. 5  illustrates a process according to one embodiment of the invention; 
         FIG. 6  is a sectional view with portions broken away of one embodiment of the invention including an insert; 
         FIG. 7  is a sectional view with portions broken away of one embodiment of the invention including two spaced apart frictional surfaces of a cast metal body portion; 
         FIG. 8  is a sectional view with portions broken away of one embodiment of the invention including an insert having a layer thereon to provide a frictional surface for damping; 
         FIG. 9  is an enlarged view of one embodiment of the invention; 
         FIG. 10  is a sectional view with portions broken away of one embodiment of the invention; 
         FIG. 11  is an enlarged sectional view with portions broken away of one embodiment of the invention; 
         FIG. 12  is an enlarged sectional view with portions broken away of one embodiment of the invention; 
         FIG. 13  is an enlarged sectional view with portions broken away of one embodiment of the invention; 
         FIG. 14  illustrates one embodiment of the invention; 
         FIG. 15  is a sectional view with portions broken away of one embodiment of the invention; 
         FIG. 16  is a sectional view with portions broken away of one embodiment of the invention; 
         FIG. 17  is a plan view with portions broken away illustrating one embodiment of the invention; 
         FIG. 18  is a sectional view taken along line  18 - 18  of  FIG. 17  illustrating one embodiment of the invention; 
         FIG. 19  is a sectional view with portions broken away illustrating one embodiment of the invention; and 
         FIG. 20  is a sectional view, with portions broken away illustrating another embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     The following description of the embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. 
     In one embodiment, a method is provided for manufacturing a part or product  500  with an insert  10  for damping, for example noise damping or simply vibration damping. The part  500  into which the insert  10  is incorporated may comprise any part  500  that could benefit from damping, for example, but not limited to, one of a brake rotor, bracket, pulley, brake drum, transmission housing, gear, motor housing, shaft, bearing, engine, baseball bat, lathe machine, milling machine, drilling machine, or grinding machine. In one embodiment, the method includes a vertical casting process. In the vertical casting embodiment, the insert  10  may rest on and be supported by a mold along a side edge of the insert  10 . In another embodiment, the method includes a horizontal casting process. In various other embodiments, the method includes a casting process performed at any suitable angle. 
     In one embodiment, the vertical casting process includes designing an insert  10  for a particular part  500 . The insert  10  may take any shape. In one embodiment shown in  FIG. 1 , the insert comprises an annular portion  12  having an inner edge  14  and an outer edge  16 . Many different characteristics are taken into consideration when designing the insert  10 . The material chosen for the insert  10  may depend to some extent on the material selected for the part  500 . Other considerations in the design of the insert  10  may be the thickness or the width of the insert  10 , as will be described in greater detail hereafter. In various embodiments, the outer diameter of the insert  10  at the outer edge  16  may be smaller than the outer diameter of the part  500  for which the insert  10  is designed. For example, the outer diameter of the insert  10  at the outer edge  16  may be about 5 mm to about 25 mm smaller than the outer diameter of the part  500 . 
     In one embodiment, the insert  10  may include at least one tab  18 . Such a tab  18  may extend from at least one of the inner edge  14  or the outer edge  16  of the annular body  12 . The thickness of the tab  18  may be such that a first mold portion  11  (shown in  FIGS. 4-5 ) and a second mold portion  13  (not shown) clamp down (crush) the tab  18  when the first mold portion  11  and the second mold portion  13  close to form a mold  15  (shown in  FIGS. 4-5 ). In the embodiment shown in  FIG. 1 , the tabs  18  extending from the inner edge  14  of the annular body  12  are shown in phantom. In one embodiment, the insert  10  may include twelve tabs. In one embodiment, the insert  10  may include an annular stiffening rib  20 . The annular stiffening rib  20  may be approximately equidistant from the inner edge  14  and the outer edge  16  of the annular body  12 . In another embodiment, the insert  10  may include a plurality of radial stiffening ribs  22 , which extend from the annular stiffening rib  20  of the annular body  12  to an outer edge  16  of the tabs  18 . 
     One embodiment of the invention may include a process including blank stamping of the insert  10 . In one embodiment, the insert  10  includes the at least one tab  18  and a portion of the tabs  18  are then bent to form a bent tab portion  28 , as shown in  FIG. 1 . The bent tab portion  28  may be bent ninety degrees relative to the remainder of the tab  18  to at least assist in holding the insert  10  in the mold  15  vertically. Or the bent tab portion  28  may be at any suitable angle relative to the remainder of the tab  18 . In one embodiment, the length of the bent tab portion  28  may be about 5 mm. 
     In one embodiment the insert  10  includes a non-wettable surface that prevents molten metal from bonding to the insert  10  surface. In one embodiment the non-wettable surface may be provided by a layer  520  of particles  514 , flakes, or fibers, as will be described in greater detail hereafter. In one embodiment, the layer  520  may be a coating including a binder and the particles  514 , flakes, or fibers over the insert  10 , or at least a portion of the insert  10  may be otherwise treated so that molten metal does not wet that portion of the insert  10  and bond thereto upon solidification of the molten metal. 
     One embodiment of the invention may include pre-treating the insert  10  prior to forming the coating over the insert. The pre-treating of the insert  10  may comprise at least one of sand blasting, grit blasting, glass bead blasting, chemical washing, or water jet degreasing. The pre-treating of the insert  10  may result in an abrasive surface on the insert  10 . In one embodiment, the pre-treating may also include a chemical cleaning to remove oxides and other surface oils prior to the coating application. In one embodiment, the insert  10  may then be pre-heated prior to coating the insert  10 . The insert  10  may be pre-heated to a temperature of about 50° C. to about 250° C. In one embodiment the insert  10  may be pre-heated to a temperature of about 75° C. For example, the insert  10  may travel through an oven to heat the insert  10 . Pre-heating the insert  10  may promote the subsequent adhesion of the coating to the insert during the coating process. 
     In one embodiment, the insert  10  may include a coating  520  (as shown in  FIGS. 15-16 ) over the entire insert  10  or only a portion thereof. In another embodiment, the annular body  12  of the insert  10  may be coated, but the tabs  18  may not be coated so that cast metal bonds to the tabs  18 . The insert  10  may be coated by any suitable method of coating, for example spraying or dipping. The coating may be capable of withstanding high temperatures used in the casting process. The coating may be sufficiently adherent to the insert  10  such that the coating does not flake or rub off during transportation or handling of the insert, or during the casting process. 
     In one embodiment, the insert  10  with the coating  520  is then baked. In various embodiments, the bake time and temperature may vary depending on the type of coating  520 . For example, in one embodiment the insert may be baked and cured for 20 minutes at a temperature of 140° C. In another embodiment, the insert may be baked for at least two hours at 350° C. Then the insert may be packaged for transportation to the molding line. The packaging may include any suitable packaging to protect the insert  10  so that the coating is not damaged. 
     Referring to  FIGS. 2A-2B , in one embodiment, the insert  10  may be pre-heated before being placed into a setting fixture  30 . In one embodiment, the insert  10  may be pre-heated to about 50° C. to about 80° C. For example, the insert  10  may travel through an oven to heat the insert  10 . This pre-heating step may remove any moisture on the insert  10  before the insert  10  is loaded in the setting fixture  30 . The insert  10  may then be placed into the setting fixture  30 . In one embodiment, the setting fixture  30  may be centered and clocked in as accurately as possible. In one embodiment, the cavity in the setting fixture  30  which holds the tabs  18  may be slightly wider than the actual width of the tab  18 . For example, the cavity may be 0.50 mm wider on each side of the tab  18 , and the setting fixture  30  may be centered to within 0.26 mm of the Total Indicator Reading (TIR) of the tab print width. The setting fixture  30  may include a vacuum  32  to partially assist in loading the insert  10  into the setting fixture  30 . The setting fixture  30  may include ejector pins  34  to partially assist in loading the insert  10  into the mold  15 . 
     In one embodiment, the setting fixture  30  is then used to load the insert  10  into one portion of the mold  15 . The ejector pins  34  may be required to push the insert  10  free when the insert is set in the sand mold  15 . In one embodiment, a relief of 3.0 mm on the outside of the tab may be required to accommodate the expansion of the insert material, for example steel, during casting. The bent tab portion  28  allows the insert  10  to be attached to the first mold portion  11 , for example, so that the bent tab portion  28  engages a lip of the first mold portion  11  so that the insert  10  hangs, is supported, or is attached to the first mold portion  11  prior to closing the mold  15 . Referring to  FIG. 3 , in one embodiment the part  500  being manufactured may be a rotor assembly  36 . The rotor assembly  36  may include a hub portion  38  and an annular rotor portion  40 . The insert  10  and the tabs  18  may be split equally at a parting line  42  in the mold  15  to ensure that the insert  10  is in the center of the annular rotor portion  40  of the rotor. To accomplish holding of the insert  10  in the mold  15 , the tab  18  print, which protrudes into the sand may have a crush of about 0.12 mm to about 0.25 mm built into the print. 
     After the insert  10  is set in the first mold portion  11  of the mold  15 , the first mold portion  11  and the second mold portion  13  (not shown) of the mold  15  may be closed together. Then the mold  15  containing the insert  10  may be moved to a pouring station. The pour rate of material into the mold  15  and the amount of inoculants may then be set. Then the material may be poured into the mold to form the part  500 . In one embodiment, the material may be, for example but is not limited to, cast iron molten metal. Referring to  FIG. 4 , a vertical casting system  44  is shown according to one embodiment of the invention. In one embodiment, the vertical casting system  44  may include a down sprue  46  for molten metal. The vertical casting system  44  may include a filter  48 . The filter  48  may be a ceramic foam filter or block strainer type. The filter  48  may be located in the down sprue  46 . The vertical casting system  44  may include at least one gate  50  which may be in the lower half of the mold  15 . The at least one gate  50  may be located between the tabs  18  of the insert  10 . In one embodiment, the insert comprises at least two tabs  18  and only one gate  50  is positioned in between two adjacent tabs  18 . The vertical casting system  44  may be biased to one side of the mold  15  instead of centered on the mold  15 . The vertical casting system  44  may minimize turbulent flows of molten metal moving to the insert. The size of each of the at least one gate  50  is dependent on casting configuration and weight. The vertical casting system  44  may also include at least one blind vent  52 . In one embodiment, there may be two blind vents  52 . In one embodiment, the vertical casting system  44  may include a riser  54  for venting. Referring now to  FIG. 5 , the vertical casting system  44  is shown with the molten metal entering the at least one gate  50  from the bottom of the mold  15 . 
     Then the mold  15  may continue down the line and cool. The cooling may include exposure to air, or it may include an active means of cooling such as, for example, a fan. The part  500  may then be removed from the mold  15  and allowed to cool further. In one embodiment, the part  500  may then be shot blasted to remove any remaining particles, for example sand, from the mold. In one embodiment, the part  500  may then be inspected for defects. The protruding tabs  18  may be machined off. In one embodiment, the part  500  may be machined further. 
     Referring to  FIGS. 6-20 , one embodiment of the invention includes a product or part  500  having a frictional damping means. The frictional damping means may be used in a variety of applications including, but not limited to, applications where it is desirable to reduce noise associated with a vibrating part or reduce the vibration amplitude and/or duration of a part that is struck, dynamically loaded, excited, or set in motion. In one embodiment the frictional damping means may include an interface boundary conducive to frictionally damping a vibrating part. In one embodiment the damping means may include frictional surfaces  502  constructed and arranged to move relative to each other and in frictional contact, so that vibration of the part is dissipated by frictional damping due to the frictional movement of the surfaces  502  against each other. 
     According to various illustrative embodiments of the invention, frictional damping may be achieved by the movement of the frictional surfaces  502  against each other. The movement of frictional surfaces  502  against each other may include the movement of: surfaces of a body  506  of the part against each other; a surface of the body  506  of the part against a surface of the insert  10 ; a surface of the body  506  of the part against the layer  520 ; a surface of the insert  10  against the layer  520 ; a surface of the body  506  of the part against the particles  514 , flakes, or fibers; a surface of the insert  10  against the particles  514 , flakes, or fibers; or by frictional movement of the particles  514 , flakes, or fibers against each other or against remaining binder material. 
     In embodiments wherein the frictional surface  502  is provided as a surface of the body  506  or the insert  10  or a layer  520  over one of the same, the frictional surface  502  may have a minimal area over which frictional contact may occur that may extend in a first direction a minimum distance of 0.1 mm and/or may extend in a second (generally traverse) direction a minimum distance of 0.1 mm. In one embodiment the insert  10  may be an annular body and the area of frictional contact on a frictional surface  502  may extend in an annular direction a distance ranging from about 20 mm to about 1000 mm and in a transverse direction ranging from about 10 mm to about 75 mm. The frictional surface  502  may be provided in a variety of embodiments, for example, as illustrated in  FIGS. 6-20 . 
     Referring again to  FIG. 6 , in another embodiment of the invention one or more of outer surfaces  522 ,  524  of the insert  10  or surfaces  526 ,  528  of the body  506  of the part  500  may include a relatively rough surface including a plurality of peaks  510  and valleys  512  to enhance the frictional damping of the part. In one embodiment, the surface of the insert  10  or the body  506  may be abraded by sandblasting, glass bead blasting, water jet blasting, chemical etching, machining or the like. 
     As shown in  FIG. 7 , in one embodiment one frictional surface  502  (for example extending from points A-B) may be a first surface of the body  506  of the part  500  positioned adjacent to a second frictional surface  502  (for example extending from points C-D) of the body  506 . The body  506  may include a relatively narrow slot-like feature  508  formed therein so that at least two of the frictional surfaces  502  defining the slot-like feature  508  may engage each other for frictional movement during vibration of the part to provide frictional damping of the part  500 . In various embodiments of the invention, the slot-like feature  508  may be formed by machining the cast part, or by using a sacrificial casting insert that may be removed after the casting by, for example, etching or machining. In one embodiment a sacrificial insert may be used that can withstand the temperature of the molten metal during casting but is more easily machined than the cast metal. Each frictional surface  502  may have a plurality of peaks  510  and a plurality of valleys  512 . The depth as indicated by line V of the valleys  512  may vary with embodiments. In various embodiments, the average of the depth V of the valleys  512  may range from about 1 μm-500 μm, 50 μm-260 μm, 100 μm-160 μm or variations of these ranges. However, for all cases there is local contact between the opposing frictional surfaces  502  during component operation for frictional damping to occur. 
     In another embodiment of the invention the damping means or frictional surface  502  may be provided by particles  514 , flakes, or fibers provided on at least one face of the insert  10  or a surface of the body  506  of the part  500 . The particles  514 , flakes, or fibers may have an irregular shape (e.g., not smooth) to enhance frictional damping, as illustrated in  FIG. 14 . One embodiment of the invention may include a layer  520  including the particles  514 , flakes, or fibers which may be bonded to each other or to a surface of the body  506  of the part or a surface of the insert  10  due to the inherent bonding properties of the particles  514 , flakes, or fibers. For example, the bonding properties of the particles  514 , flakes, or fibers may be such that the particles  514 , flakes, or fibers may bind to each other or to the surfaces of the body  506  or the insert  10  under compression. In another embodiment of the invention, the particles  514 , flakes, or fibers may be treated to provide a coating thereon or to provide functional groups attached thereto to bind the particles, flakes, or fibers together or attach the particles, flakes, or fibers to at least one of a surface of the body  506  or a surface of the insert  10 . In another embodiment of the invention, the particles  514 , flakes, or fibers may be embedded in at least one of the body  506  of the part or the insert  10  to provide the frictional surface  502  ( FIGS. 9-10 ). 
     In embodiments wherein at least a portion of the part  500  is manufactured such that the insert  10  and/or the particles  514 , flakes, or fibers are exposed to the temperature of a molten material such as in casting, the insert  10  and/or particles  514 , flakes, or fibers may be made from materials capable of resisting flow or resisting significant erosion during the manufacturing. For example, the insert  10  and/or the particles  514 , flakes, or fibers may include refractory materials capable of resisting flow or that do not significantly erode at temperatures above 600° C., above 1300° C., or above 1500° C. When molten material, such as metal, is cast around the insert  10  and/or the particles  514 , flakes, or fibers, the insert  10  or the particles  514 , flakes, or fibers should not be wet by the molten material so that the molten material does not bond to the insert  10  or layer  520  at locations wherein a frictional surface  502  for providing frictional damping is desired. 
     Illustrative examples of suitable particles  514 , flakes, or fibers include, but are not limited to, particles, flakes, or fibers including silica, alumina, graphite with clay, silicon carbide, silicon nitride, cordierite (magnesium-iron-aluminum silicate), mullite (aluminum silicate), zirconia (zirconium oxide), phyllosilicates, or other high-temperature-resistant particles, flakes, or fibers. In one embodiment of the invention the particles  514 , flakes, or fibers may have a length along the longest dimension thereof ranging from about 1 μm-500 μm, or 10 μm-250 μm. 
     In another embodiment of the invention, the layer  520  may be a coating over the body  506  of the part or the insert  10 . The coating may include a plurality of particles  514 , flakes, or fibers which may be bonded to each other and/or to the surface of the body  506  of the part or the insert  10  by an inorganic or organic binder  516  ( FIGS. 8, 13 ) or other bonding materials. Illustrative examples of suitable binders include, but are not limited to, epoxy resins, phosphoric acid binding agents, calcium aluminates, sodium silicates, wood flour, or clays. In another embodiment of the invention the particles  514 , flakes, or fibers may be held together and/or adhered to the body  506  or the insert  10  by an inorganic binder. In one embodiment, the coating may be deposited on the insert  10  or body  506  as a liquid dispersed mixture of alumina-silicate-based, organically bonded refractory mix. 
     In another embodiment, the coating may include at least one of alumina or silica particles, mixed with a lignosulfonate binder, cristobalite (SiO 2 ), quartz, or calcium lignosulfonate. The calcium lignosulfonate may serve as a binder. In one embodiment, the coating may include IronKote. In one embodiment, a liquid coating may be deposited on a portion of the insert and may include high temperature Ladle Kote 310B. In another embodiment, the coating may include at least one of clay, Al 2 O 3 , SiO 2 , a graphite and clay mixture, silicon carbide, silicon nitride, cordierite (magnesium-iron-aluminum silicate), mullite (aluminum silicate), zirconia (zirconium oxide), or phyllosilicates. In one embodiment, the coating may comprise a fiber such as ceramic or mineral fibers. 
     When the layer  520  including particles  514 , flakes, or fibers is provided over the insert  10  or the body  506  of the part the thickness L ( FIG. 8 ) of the layer  520 , particles  514 , flakes, and/or fibers may vary. In various embodiments, the thickness L of the layer  520 , particles  514 , flakes, and/or fibers may range from about 1 μm-500 μm, 10 μm-400 μm, 30 μm-300 μm, 30 μm-40 μm, 40 μm-100 μm, 100 μm-120 μm, 120 μm-200 μm, 200 μm-300 μm, 200 μm-250 μm, or variations of these ranges. 
     In yet another embodiment of the invention the particles  514 , flakes, or fibers may be temporarily held together and/or to the surface of the insert  10  by a fully or partially sacrificial coating. The sacrificial coating may be consumed by molten metal or burnt off when metal is cast around or over the insert  10 . The particles  514 , flakes, or fibers are left behind trapped between the body  506  of the cast part and the insert  10  to provide a layer  520  consisting of the particles  514 , flakes, or fibers or consisting essentially of the particles  514 , flakes, or fibers. 
     The layer  520  may be provided over the entire insert  10  or only over a portion thereof. In one embodiment of the invention the insert  10  may include a tab  534  ( FIG. 8 ). For example, the insert  10  may include an annular body portion and a tab  534  extending radially inward or outward therefrom. In one embodiment of the invention at least one wettable surface  536  of the tab  534  does not include a layer  520  including particles  514 , flakes, or fibers, or a wettable material such as graphite is provided over the tab  534 , so that the cast metal is bonded to the wettable surface  536  to attach the insert  10  to the body  506  of the part  500  but still allow for frictional damping over the remaining insert surface which is not bonded to the casting. 
     In one embodiment of the invention at least a portion of the insert  10  is treated or the properties of the insert  10  are such that molten metal will not wet or bond to that portion of the insert  10  upon solidification of the molten metal. According to one embodiment of the invention at least one of the body  506  of the part or the insert  10  includes a metal, for example, but not limited to, aluminum, steel, stainless steel, cast iron, any of a variety of other alloys, or metal matrix composite including abrasive particles. In one embodiment of the invention the insert  10  may include a material such as a metal having a higher melting point than the melting point of the molten material being cast around a portion thereof. 
     In one embodiment the insert  10  may have a minimum average thickness of 0.2 mm and/or a minimum width of 0.1 mm and/or a minimum length of 0.1 mm. In another embodiment the insert  10  may have a minimum average thickness of 0.2 mm and/or a minimum width of 2 mm and/or a minimum length of 5 mm. In other embodiments the insert  10  may have a thickness ranging from about 0.1-20 mm, 0.1-6.0 mm, or 1.0-2.5 mm, or ranges therebetween. 
     Referring now to  FIGS. 11-13 , again the frictional surface  502  may have a plurality of peaks  510  and a plurality of valleys  512 . The depth as indicated by line V of the valleys  512  may vary with embodiments. In various embodiments, the average of the depth V of the valleys  512  may range from about 1 μm-500 μm, 50 μm-260 μm, 100 μm-160 μm or variations of these ranges. However, for all cases there is local contact between the body  506  and the insert  10  during component operation for frictional damping to occur. 
     In other embodiments of the invention improvements in the frictional damping may be achieved by adjusting the thickness (L, as shown in  FIG. 8 ) of the layer  520 , or by adjusting the relative position of opposed frictional surfaces  502  or the average depth of the valleys  512  (for example, as illustrated in  FIG. 7 ). 
     In one embodiment the insert  10  is not pre-loaded or under pre-tension or held in place by tension. In one embodiment the insert  10  is not a spring. Another embodiment of the invention includes a process of casting a material comprising a metal around an insert  10  with the proviso that the frictional surface  502  portion of the insert used to provide frictional damping is not captured and enclosed by a sand core that is placed in the casting mold. In various embodiments the insert  10  or the layer  520  includes at least one frictional surface  502  or two opposite friction surfaces  502  that are completely enclosed by the body  506  of the part. In another embodiment the layer  520  including the particles  514 , flakes, or fibers that may be completely enclosed by the body  506  of the part or completely enclosed by the body  506  and the insert  10 , and wherein at least one of the body  506  or the insert  10  comprises a metal or consists essentially of a metal. In one embodiment of the invention the layer  520  and/or insert  10  does not include or is not carbon paper or cloth. 
     Referring again to  FIGS. 6-8 , in various embodiments of the invention the insert  10  may include a first face  522  and an opposite second face  524  and the body  506  of the part may include a first inner face  526  adjacent the first face  522  of the insert  10  constructed to be complementary thereto, for example nominally parallel thereto. The body  506  of the part includes a second inner face  528  adjacent to the second face  524  of the insert  10  constructed to be complementary thereto, for example parallel thereto. The body  506  may include a first outer face  530  overlying the first face  522  of the insert  10  constructed to be complementary thereto, for example parallel thereto. The body  506  may include a first outer face  532  overlying the second face  524  of the insert  10  constructed to be complementary thereto, for example parallel thereto. However, in other embodiments of the invention the outer faces  530 ,  532  of the body  506  are not complementary to associated faces  522 ,  524  of the insert  10 . When the damping means is provided by a narrow slot-like feature  508  formed in the body  506  of the part  500 , the slot-like feature  508  may be defined in part by a first inner face  526  and a second inner face  528  which may be constructed to be complementary to each other, for example parallel to each other. In other embodiments the surfaces  526  and  528 ;  526  and  522 ; or  528  and  524  are mating surfaces but not parallel to each other. 
     Referring to  FIGS. 15-16 , in one embodiment of the invention the insert  10  may be an inlay wherein a first face  522  thereof is not enclosed by the body  506  of the part. The insert  10  may include a tang or tab  534  which may be bent downward as shown in  FIG. 15 . In one embodiment of the invention a wettable surface  536  may be provided that does not include a layer  520  including particles  514 , flakes, or fibers, or a wettable material such as graphite is provided over the tab  534 , so that the cast metal is bonded to the wettable surface  536  to attach the insert  10  to the body of the part but still allow for frictional damping on the non-bonded surfaces. A layer  520  including particles  514 , flakes, or fibers may underlie the portion of the second face  524  of the insert  10  not used to make the bent tab  534 . 
     In another embodiment the insert  10  includes a tab  534  which may be formed by machining a portion of the first face  522  of the insert  10  ( FIG. 16 ). The tab  534  may include a wettable surface  536  having cast metal bonded thereto to attach the insert  10  to the body of the part but still allow for friction damping by way of the non-bonded surfaces. A layer  520  including particles  514 , flakes, or fibers may underlie the entire second face  524  or a portion thereof. In other embodiments of the invention all surfaces including the tabs  534  may be non-wettable, for example by way of a coating  520  thereon, and features of the body portion  506  such as, but not limited to, a shoulder  537  may be used to hold the insert  10  in place. 
     Referring now to  FIG. 17 , one embodiment of the invention may include a part  500  having a body portion  506  and an insert  10  enclosed by the body part  506 . The insert  10  may include through holes formed therein so that a stake or post  540  extends into or through the insert  10 . 
     Referring to  FIG. 18 , which is a sectional view of  FIG. 17  taken along line  18 - 18 , in one embodiment of the invention a layer  520  including a plurality of particles  514 , flakes, or fibers (not shown) may be provided over at least a portion of the insert  10  to provide a frictional surface  502  and to prevent bonding thereto by cast metal. The insert  10  including the layer  520  may be placed in a casting mold and molten metal may be poured into the casting mold and solidified to form the post  540  extending through the insert  10 . An inner surface  542  defining the through hole of the insert  10  may be free of the layer  520  or may include a wettable material thereon so that the post  540  is bonded to the insert  10 . Alternatively, in another embodiment the post  504  may not be bonded the insert  10  at the inner surface  542 . The insert  10  may include a feature such as, but not limited to, a shoulder  505  and/or the post  540  may include a feature such as, but not limited to, a shoulder  537  to hold the insert in place. 
     Referring now to  FIG. 19 , in another embodiment, the insert may be provided as an inlay in a casting including a body portion  506  and may include a post  540  extending into or through the insert  10 . The insert  10  may be bonded to the post  540  to hold the insert in place and still allow for frictional damping. In one embodiment of the invention the insert  10  may include a recess defined by an inner surface  542  of the insert  10  and a post  540  may extend into the insert  10  but not extend through the insert  10 . In one embodiment the post  504  may not be bonded to the insert  10  at the inner surface  542 . The insert  10  may include a feature such as, but not limited to, a shoulder  505  and/or the post  540  may include a feature such as, but not limited to, a shoulder  537  to hold the insert in place. 
     Referring now to  FIG. 20 , in another embodiment of the invention, an insert  10  or substrate may be provided over an outer surface  530  of the body portion  506 . A layer  520  may or may not be provided between the insert  10  and the outer surface  530 . The insert  10  may be constructed and arranged with through holes formed therethrough or a recess therein so that cast metal may extend into or through the insert  10  to form a post  540  to hold the insert in position and still allow for frictional damping. The post  540  may or may not be bonded to the insert  10  as desired. The post  540  may extend through the insert  10  and join another portion of the body  506  if desired. 
     When the term “over,” “overlying,” “overlies,” “under,” “underlying,” or “underlies” is used herein to describe the relative position of a first layer or component with respect to a second layer or component such shall mean the first layer or component is directly on and in direct contact with the second layer or component or that additional layers or components may be interposed between the first layer or component and the second layer or component. 
     The above description of embodiments of the invention is merely exemplary in nature and, thus, variations thereof are not to be regarded as a departure from the spirit and scope of the invention.