Methods of fabricating reduced weight components

Methods of fabricating reduced weight components for apparatuses include providing a plurality of layers from a component core including a relatively lightweight material to an outer layer including a relatively heavyweight material heavier in weight than the relatively lightweight material, the plurality of layers having increasingly higher proportions of the relatively heavyweight material than the relatively lightweight material from the component core to the outer layer; and diffusion bonding the plurality of layers and the outer layer by consolidation of the layers.

FIELD

Illustrative embodiments of the disclosure generally relate to aircraft and racing vehicles and other apparatuses which are subject to strict weight requirements. More particularly, illustrative embodiments of the disclosure relate to methods of fabricating reduced weight components while retaining contact wear resistance of the components for apparatuses which are subject to strict weight requirements by exploiting differences in the weights of materials used to fabricate the components.

BACKGROUND

The background description provided herein is solely for the purpose of generally presenting the context of the illustrative embodiments of the disclosure. Aspects of the background description are neither expressly nor impliedly admitted as prior art against the claimed subject matter.

Aircraft and vehicles, particularly those used in military and racing applications, are frequently subjected to strict weight requirements to maximize their capability to carry personnel, equipment and ordinance, as well as compete in the sport of racing. In some of these applications, for example, reducing the weight of a helicopter by just a few pounds may contribute to the carrying capacity of the helicopter. In such applications, therefore, it may be desirable to reduce the weight of as many components as possible of the aircraft, vehicle or other apparatus in order to reduce the weight of the apparatus to within or below the mandated weight restriction guidelines.

Reduction in weight of the components in vehicles which are subject to strict weight requirements may be necessary to optimize weight, strength and wear resistance of the components, particularly components such as gears which generate and transmit power. Due to its inherent strength and high melting point, titanium may be particularly applicable as the body or core of these components. However, titanium has low contact resistance and is vulnerable to immediate wear and galling. Thus, the use of a composite including titanium and some wear-resistant material such as steel alloys which modifies the surface of the titanium may be necessary to achieve this optimization.

Combining titanium and steel may theoretically be accomplished by soldering or brazing, mechanical fastening, thermal spraying, or by some form of cladding. However, due to component shape, differential thermal expansion, type of application loading or access to the attachment process, cladding is a viable option to facilitate application of the typically steel alloy wear-resistant material to the typically titanium core of the component.

In developing a lightweight composite material which is suitable for power transmission and heavy dynamic fluctuating stresses in the components, the juncture of the steel and titanium may undergo significant stress concentrations due to the differences in crystal lattice structures, microstructures, differential thermal expansion, and differential modulii of elasticity between these materials. Moreover, brittle intermetallics may be generated with the fusing of steel and titanium. Also, the typically steel contacting surfaces of these components will be exposed to another condition new to the industry. Gear teeth mesh, also known as gear contact ratio, is notoriously limited in gear applications. In such applications, it is difficult to ensure maximum surface area and evenly stress-distributed contact between gear teeth of meshing gears. By utilizing the less-rigid characteristics of titanium, it may be possible to a limited extent for mating gear teeth to better conform to each other through material deformation under load. Thus, this may require the steel surface of the gear teeth to deform and conform as well.

Accordingly, methods of fabricating reduced weight components while retaining contact wear resistance of the components, particularly power transmission components, for apparatuses which are subject to strict weight requirements by exploiting differences in the weights of materials used to fabricate the components may be desirable.

SUMMARY

Illustrative embodiments of the disclosure are generally directed to methods of fabricating reduced weight components while retaining contact wear resistance of the components for apparatuses which are subject to strict weight requirements by exploiting differences in the weights of materials used to fabricate the components. The methods may include providing a plurality of layers from a component core including a relatively lightweight material to an outer layer including a relatively heavyweight material heavier in weight than the relatively lightweight material, the plurality of layers having increasingly higher proportions of the relatively heavyweight material than the relatively lightweight material from the component core to the outer layer; and diffusion bonding the plurality of layers and the outer layer by consolidation of the layers.

A slightly modified illustrative embodiment of the methods may include obtaining a component core including a first material; forming a base layer including a mixture having the first material and a second material heavier in weight than the first material on the component core, the base layer having a higher proportion of the first material than the second material; forming at least one mixed layer including a mixture of the first material and the second material on the base layer, the at least one mixed layer having a higher proportion of the second material than the base layer; forming a final layer including the second material on the at least one mixed layer; and consolidating the base layer, the at least one mixed layer and the final layer to diffusion bond the layers.

Another slightly modified illustrative embodiment of the methods may include obtaining a component shaft including a relatively lightweight material; placing a stabilizing structure on the component shaft; placing a can over the stabilizing structure; forming a base layer including a mixture having the relatively lightweight material and a relatively heavyweight material heavier in weight than the relatively lightweight material on the component shaft and the stabilizing structure, the base layer having a higher proportion of the relatively lightweight material than the relatively heavyweight material; forming at least one mixed layer including a mixture of the relatively lightweight material and the relatively heavyweight material on the base layer, the at least one mixed layer having a higher proportion of the relatively heavyweight material than the base layer; forming an outer layer including the relatively heavyweight material on the at least one mixed layer; diffusion bonding the base layer, the at least one mixed layer and the outer layer by consolidation of the layers; and cutting component features in the base layer, the at least one mixed layer and the outer layer.

DETAILED DESCRIPTION

Illustrative embodiments of the disclosure are generally directed to methods of fabricating reduced weight components while retaining contact wear resistance of the components for apparatuses which are subject to strict weight requirements by exploiting differences in the weights of materials used to fabricate the components. The methods may include cladding of steel to a titanium alloy by loosely thermal spraying the powdered steel or steel alloy onto the titanium by way of a series of gradient layers, the particles of which are barrier-protected from direct contact. The powder may be thermally sprayed in a loosely-packed manner to fit various irregularly-shaped components and enhance the efficiency of the HIP-processed diffusion bonding. The methods may include the use of semi-consolidated sub parts such as shafts, spiral bevel pinions, roller bearing components and the like which are fabricated of a relatively lightweight material such as titanium and sprayed over with a relatively heavyweight material such as steel or steel alloy to enhance diffusion bonding.

Direct bonding of titanium and steel may generate brittle Ti3Fe compounds. Therefore, diffusion bonding which includes gradient layering of titanium and steel powder particles and the use of barrier particles between the titanium body or core and the steel or steel alloy contact surfaces of the component may be necessary to prevent direct contact of the steel with the titanium. The barrier particles may include a titanium or steel particle core with a particle coating of a neutral metal such as niobium (Nb), rhenium (Re) and/or vanadium (V), for example and without limitation. The particle coating may be applied to the particle core using CVD (chemical vapor deposition), electroplating or other suitable deposition processes known by those skilled in the art. Gradient layering of the titanium and steel along with the barrier particles may prevent stress concentrations due to the differences in crystal lattice structures, microstructures, differential thermal expansion, and differential modulii of elasticity between titanium and steel. The gradient-layered titanium and steel powder particles may be thermally-sprayed as loosely as possible to enhance diffusion bonding.

The methods of the disclosure may be broadly classified as two procedures, both of which may utilize a method of hermetically sealing the thermally- and loosely-sprayed powdered steel or steel alloy and/or thermally-sprayed composite and subjecting it to Hot Isostatic Press (HIP) processing for consolidation. In the first procedure, a sacrificial metal blank or mold may be formed as a final component mirror image. Into this mold, steel powder particles may be thermally sprayed, with the first spray being that which will be the working surface of the final finished component. In this procedure, there must be access to the mold surface for the spray gun to apply the layers.

In the second procedure, the reverse process may be utilized. Thus, the shape or size of the final component may be such that it is impossible to spray into a mirror or reverse image mold. Therefore, a center core of titanium (which may be porous for ease of diffusion bonding) may be utilized as a base upon which the steel is sprayed through the layered gradient system. The last layer of spray may be the steel which becomes the working surface of the final finished component.

Referring initially toFIG. 1of the drawings, an exemplary spur gear1which is fabricated according to an illustrative embodiment of the methods of fabricating reduced weight components is illustrated. The spur gear1may be a component of a gearbox (not illustrated) which is used in the transmission of a helicopter or other aircraft or an auto racing or other vehicle, for example and without limitation. The spur gear1may include an annular gear body or core2through which extends a drive shaft opening3. Gear teeth4are provided in the outer surface of the gear core2. As will be hereinafter further described, the gear core2is fabricated of a relatively lightweight material such as titanium or titanium-aluminum alloy, for example and without limitation. The gear teeth4are formed at least in part of a material which has higher wear resistance than the lower-weight material of which the gear core2is made and may be heavier in weight than the material of the gear core2. The relatively heavyweight material imparts substantial wear resistance to the gear teeth4.

The relatively lightweight material of the gear core2substantially reduces the weight of the spur gear1over the weights of gears fabricated using conventional methods and materials. In some embodiments, the gear core2may be fabricated of titanium or titanium-aluminum alloy whereas the gear teeth4may be formed at least in part of steel or steel alloy, for example and without limitation, to enhance the contact and wear resistance of the gear teeth4while optimizing the overall weight of the spur gear1particularly for applications in which the spurgear1is subject to strict weight requirements. Additional gears and other components such as bearings of the gearbox may be fabricated according to the methods of fabricating reduced weight components to substantially reduce the overall weight of the helicopter or other aircraft. Together, the lighter-weight components reduce the weight of the aircraft to within or below the mandated weight restriction guidelines for the aircraft, particularly in the case of aircraft which are subject to strict weight requirements such as in military and other applications.

Referring next toFIGS. 2-11of the drawings, sequential fabrication of the spur gear1according to an illustrative embodiment of the methods of fabricating reduced weight components is illustrated. As illustrated inFIG. 2, a sacrificial gear mold or blank6is provided. In some embodiments, the sacrificial gear blank6may include an elongated bar stock of material such as C1018 steel, for example and without limitation. In other embodiments, alternative materials for the sacrificial gear blank6may be used according to different applications of the methods. The sacrificial gear blank6may have a front blank surface6aand a rear blank surface6b.

As illustrated inFIG. 3, a reverse image mold may be fabricated by forming a reverse image of the gear teeth4(FIG. 1) which will ultimately be formed in the gear core2. The reverse image of the gear teeth may be cut in the front blank surface6a, forming multiple gear teeth undercuts10. The gear teeth undercuts10may be made in the front blank surface6ausing conventional machining techniques known by those skilled in the art. Each gear teeth undercut10has undercut surfaces11.

As illustrated inFIG. 4, an outer layer14may be applied over the undercut surfaces11of the gear teeth undercuts10and the portions of the front blank surface6awhich remain between the gear teeth undercuts10. In some embodiments, the outer layer14may be applied over the undercut surfaces11and the remaining portions of the front blank surface6aby spraying a particulate material of which the outer layer14will be made on the undercut surfaces11and the remaining portions of the front blank surface6aas loosely as possible using conventional thermal spraying techniques known by those skilled in the art. The outer layer14may include a mixture having the relatively heavyweight material and at least one relatively lightweight material of which the gear core2will be made, with a higher proportion of the relatively heavyweight material than the lightweight material. In some embodiments, the outer layer14may include a mixture of about 95% by weight alloy steel and about 5% by weight titanium alloy, for example and without limitation. In some embodiments, hard surface particles such as carbide may be added to the powder particles of the relatively heavyweight material to enhance surface wear resistance.

As illustrated inFIG. 5, at least one barrier layer or mixed layer16may be applied over the outer layer14. In some embodiments, the mixed layer(s)16may be applied over the outer layer14by loosely spraying the particulate mixed layer material on the outer layer14using conventional thermal spraying techniques. The mixed layer16may include a mixture having the relatively heavyweight material of which the contact surfaces of the gear1will be made and at least one relatively lightweight material of which the gear core2will be made. One or more of the mixed layers16closest to the outer layer14may have a higher proportion of the relatively heavyweight material than the relatively lightweight material, with a higher proportion of the relatively lightweight material than is provided in the outer layer14. Successive mixed layers16may have gradually progressively higher proportions of the relatively lightweight material than preceding mixed layers16which are closer to the outer layer14. In some embodiments, the outer layer14and the transitional mixed layer or layers16may have a total thickness of about 50,000-100,000s of an inch. A base layer17may in like manner be applied over the outermost mixed layer16. The base layer17may include the relatively lightweight material of which the gear core2will be made without the relatively heavyweight material.

As illustrated inFIG. 6, a barrier plate or “fence”30may be placed in spaced-apart relationship to the base layer17. The spacing between the fence30and the base layer17may correspond to the radial thickness of the gear core2. A powder layer18may next be applied over the base layer17. The powder layer18may overfill each layered gear teeth undercut10and the layered remaining portions of the front blank surface6aas well as the space between the fence30and the base layer17. In some embodiments, the powder layer18may be applied over the base layer17by spraying the particulate transition layer material on the base layer17using conventional thermal spraying techniques or by filling the required volume between the base layer17and the fence30with powder or porous solid. The powder layer18may include the relatively lightweight material of which the gear core2will be made. In some embodiments, the powder layer18may include a titanium/aluminum/vanadium alloy such as Ti6Al-4V containing 90% Ti, 6% aluminum and 4% vanadium, for example and without limitation.

As illustrated inFIG. 7, a can20may be applied over the powder layer18. In some embodiments, the can20may include a steel plate, for example and without limitation. As illustrated inFIG. 8, the can20may be hermetically sealed against the powder layer18such as by welding22, for example and without limitation. In some embodiments, the fence30(FIG. 6) may remain in place as the can20.

As illustrated inFIG. 9, the sacrificial gear blank6, the layers14,16,17, the powder layer18and the can20may be subjected to HIP (Hot Isostatic Press) processing24. The HIP processing24may be carried out in a standard or conventional HIP furnace known by those skilled in the art. Non-limiting exemplary process parameters for the HIP processing24may include HIP temperatures of typically from about 1700 to 2100 degrees F. and HIP pressures of from about 15,000 to about 30,000 psi applied to the can20. The HIP pressure may be applied using argon or other inert gas as is known by those skilled in the art. Accordingly, the HIP processing24presses the can20against the powder layer18, removing voids in the powder layer18and forming the gear core2(FIG. 10) of the gear1which is substantially free of voids and is metallurgically fused to the outer layer14, the mixed layer(s)16, the base layer17and the sacrificial gear blank6. After the HIP processing24is completed, the can20may be removed from the underlying gear core2using machine cutting tools or other suitable techniques known by those skilled in the art. In some embodiments, the can20may be thermally sprayed and consolidated using mechanical forces or impacting according to the knowledge of those skilled in the art prior to HIP processing.

As illustrated inFIGS. 10 and 11, the gear teeth4(FIG. 11) may be cut in rear blank surface6bof the sacrificial gear blank6using conventional machining techniques known by those skilled in the art. The gear teeth4correspond to the reverse image of the gear teeth undercuts10which were previously made in the front blank surface6a(FIG. 3). Accordingly, the base layer17and the mixed layer(s)16may together form a transition layer12between the gear core2and the outer layer14, which forms the contact surface of the gear teeth4.

After fabrication is completed, the gear1may be subjected to post-processing. Post-processing of the gear1may include heat treatment at about 1500 degrees F., followed by quenching and machining or grinding of the precise gear dimensions into the gear teeth4according to the knowledge of those skilled in the art. The relatively lightweight material composition of the gear core2dramatically reduces the weight of the gear1, whereas the relatively heavyweight material composition of the gear teeth4enhances the wear resistance characteristics of the gear teeth4.

Referring next toFIGS. 11A and 11Bof the drawings, a sectional view of a portion of a gear1fabricated according to the illustrative embodiment of the methods of fabricating reduced weight components ofFIGS. 1-11is illustrated. The transition layer12between the gear core2and the outer layer14may have an undulating cross-sectional profile with transition layer crests12awhich extend into the respective gear teeth4and transition layer troughs12bbetween the transition layer crests12a. A tooth root5extends between each pair of adjacent gear teeth4. As illustrated inFIG. 11B, in some embodiments, the transition layer crests12aof the transition layer12may protrude beyond the tooth roots5between the adjacent gear teeth4. The methods may be used to fabricate gears1in which up to 50% or more of the volume of the gear1is fabricated of titanium and/or other relatively lightweight material. The gear roots5may be undercut and shaped to follow lines of stress applied to the gear teeth4and may accord with flexural and torsional loading on the gear1.

The gear core2of the gear1can be attached to a gear shaft (not illustrated) using mechanical fastening or Hot Isostatic Press (HIP) cladding, for example and without limitation, according to the knowledge of those skilled in the art. As illustrated inFIG. 11B, in an exemplary mechanical fastening application, a threaded mount opening32may be provided in the gear core2. A threaded fastener (not illustrated) may threadably engage the threaded mount opening32and a registering mount opening (not illustrated) in the gear shaft to secure the gear1on the gear shaft.

In HIP cladding methods, the joining surfaces of the gear core2and the gear shaft may be machined to form a suitable interface. HIP processing may be carried out under high argon pressure (˜15,000 psi) at temperatures of over 1700 degrees F. Alternative techniques known by those skilled in the art may be used to secure the gear core2of the gear1to the gear shaft.

Referring next toFIG. 11Cof the drawings, in some implementations of the methods of fabricating reduced weight components, the mixed layer16(FIGS. 6-11) may include hybrid particles26each having a particle core27and a particle coating28on the particle core27. In some applications, the particle core27may include the relatively lightweight material such as titanium or titanium-aluminum alloy, for example and without limitation, which is used to fabricate the gear core2. In some applications, the particle core27may include the relatively heavyweight material such as steel, for example and without limitation, which is used to fabricate the base layer17. The particle coating28may include niobium (Ni), Vanadium (V) and/or Rhenium (Re), for example and without limitation. The particle coating28may be deposited on the particle core27using any of a variety of deposition techniques which are suitable for the purpose, including but not limited to chemical vapor deposition (CVD) and electroplating. Accordingly, the hybrid particles26may prevent or minimize direct contact and joining of the relatively heavyweight particles (typically steel) with the relatively lightweight particles (typically titanium) in the outer layer14, the mixed layer16and the base layer17, and thus, the undesired generation of brittle Ti3Fe inter-metallic compounds.

Referring next toFIG. 12of the drawings, a flow diagram of a method of fabricating a reduced weight gear such as the spur gear1inFIG. 1, for example and without limitation, according to an illustrative embodiment of the methods of fabricating reduced weight components is generally indicated by reference numeral100. In block102, a sacrificial gear blank is provided. The sacrificial gear blank may have a front blank surface and a rear blank surface. In block104, a reverse image of the gear teeth which will ultimately be formed in the gear is undercut in the front gear surface of the sacrificial gear blank to form a reverse image mold. In block106, an outer layer may be applied to the surfaces of the undercuts and the portions of the front blank surface which remain between the undercuts using thermal spraying or other suitable technique. The outer layer may include the relatively heavyweight material which will ultimately form the contact surfaces of the gear teeth.

In block108, at least one mixed layer may be applied over the outer layer using thermal spraying or other suitable technique. The mixed layer may include a mixture of the relatively heavyweight material and at least one relatively lightweight material of which the gear core will be made. One or more of the mixed layers closest to the outer layer may have a higher proportion of the relatively heavyweight material than the relatively lightweight material. Successive mixed layers may have gradually progressively higher proportions of the relatively lightweight material than preceding mixed layers. In some embodiments, one or more of the mixed layers may include hybrid particles. In block110, a base layer may be applied over the outermost mixed layer. The base layer may include the relatively lightweight material of which the gear core will be made without the relatively heavyweight material.

In block112, a barrier plate or “fence” may be placed in spaced-apart relationship to the base layer. In block114, the space between the fence and the base layer may be filled with a porous solid material or a powder layer which is applied over the base layer and confined by the barrier plate or fence. The powder layer may include the relatively lightweight material of which the gear core will be made. In block116, the can may be hermetically sealed against the powder layer such as by welding, for example and without limitation.

In block118, the gear core may be formed from the porous solid material or powder layer by subjecting the sacrificial gear blank, the outer layer, the mixed layer(s), the base layer and the powder layer to HIP processing in which the can is pressed against and eliminates voids in the powder layer. In some embodiments, the can may be thermally sprayed and consolidated using mechanical forces or impacting according to the knowledge of those skilled in the art prior to HIP processing. In block120, the sacrificial gear blank is cut away to the outer layer. Accordingly, the outer layer, the mixed layer(s) and the base layer form the gear teeth with the outer layer remaining exposed as the contact surfaces of the gear teeth. The gear teeth correspond to a reverse image of the gear teeth undercuts which were made in the gear blank in block104. In block122, the gear may be subjected to post-processing steps such as heat-treatment, quenching and machining or grinding, for example and without limitation, according to methods which are known by those skilled in the art.

It will be appreciated by those skilled in the art that the methods of fabricating reduced weight components as heretofore described with respect to fabrication of the spur gear1inFIGS. 1-12can be used to fabricate a variety of components of aircraft, vehicles or other apparatuses which are subjected to strict weight requirements. The methods may be used to fabricate reduced weight components in multiple locations and mechanisms within an aircraft, vehicle or other apparatus as part of a comprehensive strategy to reduce the overall weight of the apparatus to within or even beyond the weight restriction guidelines for the apparatus.

Referring next toFIGS. 13-15Aof the drawings, sequential fabrication of roller bearings40for a roller bearing assembly36(FIG. 13) according to an illustrative embodiment of the methods of fabricating reduced weight components is illustrated. As illustrated inFIG. 13, the roller bearing assembly36may include an annular outer race37and a cylindrical inner race38inside the outer race37. Multiple roller bearings40are disposed between the outer race37and the inner race38. The roller bearing assembly36used in the transmission of a helicopter or other aircraft or an auto racing or other vehicle, for example and without limitation.

As illustrated inFIG. 14, a roller bearing core44is provided. In some embodiments, the roller bearing core44may include an elongated bar stock of a relatively lightweight material such as titanium, for example and without limitation. A non-limiting example of a material which is suitable for the roller bearing core44may include a titanium/aluminum/vanadium alloy such as Ti6Al-4V containing 90% Ti, 6% aluminum and 4% vanadium.

As illustrated inFIG. 15, the roller bearings40are cut from the roller bearing core44typically using conventional machining techniques known by those skilled in the art. The adjacent roller bearings40may remain connected to each other in end-to-end relationship.

As illustrated inFIG. 15A, a base layer54may initially be applied over the race contact surface41of each roller bearing40. In some embodiments, the base layer54may be applied over the race contact surface41by loosely spraying a particulate material of which the base layer54will be made on the race contact surface41using conventional thermal spraying techniques known by those skilled in the art. The base layer54may include a mixture having the relatively lightweight material of which the roller bearing core44(FIG. 14) is made and at least one relatively heavyweight material, with a higher proportion of the relatively lightweight material than the relatively heavyweight material. In some embodiments, the base layer54may include a mixture of about 95% by weight titanium and about 5% by weight 52100 steel, for example and without limitation.

As further illustrated inFIG. 15A, at least one mixed layer56may be applied over the base layer54. In some embodiments, the mixed layer56may be applied over the base layer54by loosely spraying the particulate mixed layer material on the base layer54using conventional thermal spraying techniques. The mixed layer56may include a mixture having the relatively lightweight material of which the roller bearing core44is made and at least one relatively heavyweight material. One or more of the mixed layers56closest to the base layer54may have a higher proportion of the relatively lightweight material than the relatively heavyweight material. Successive mixed layers56may have gradually progressively higher proportions of the relatively heavyweight material than preceding mixed layers56which are closer to the base layer54. In some embodiments, one or more of the mixed layers56may include hybrid particles26(FIG. 11C). In some non-limiting embodiments, the base layer54and the transitional mixed layer or layers56may have a total thickness of up to about 100,000s of an inch. An outer layer57may in like manner be applied over the outermost mixed layer56. The outer layer57may include the relatively heavyweight material without the relatively lightweight material to increase the contact resistance of the race contact surface41of each finished roller bearing40.

As illustrated inFIG. 15, the sprayed roller bearings40may be placed in a can46having a can interior47. In some embodiments, the can46may include a sealed steel tube, for example and without limitation. A filler powder50may next be applied over the outer layer57(FIG. 15A) on the roller bearings40. The filler powder50may fill the can interior47between the interior surface of the can46and the roller bearings40. In some embodiments, the filler powder50may be applied over the outer layer57using conventional thermal spraying techniques. In some embodiments, the filler powder50may include mild steel powder, for example and without limitation. After application of the filler powder50, the can46may be hermetically sealed such as by welding, for example and without limitation, according to the knowledge of those skilled in the art.

The roller bearings40may next be subjected to HIP (Hot Isostatic Press) processing. The HIP processing may be carried out in a standard or conventional HIP furnace known by those skilled in the art. Exemplary process parameters for the HIP processing may include HIP temperatures of typically from about 1700 to 2100 degrees F. and HIP pressures of from about 15,000 to about 30,000 psi applied to the can46. The HIP pressure may be applied to the can46using argon or other inert gas as is known by those skilled in the art. Accordingly, the HIP processing presses the can46against the filler powder50, the outer layer57, the mixed layer(s)56, the base layer54and the roller bearing core44. After the HIP processing is completed, the can46and filler powder50may be removed from the roller bearings40using machine cutting tools or other suitable machining techniques known by those skilled in the art. In some embodiments, the can may be thermally sprayed and consolidated using mechanical forces or impacting according to the knowledge of those skilled in the art prior to HIP processing.

After fabrication is completed, the roller bearings40may be subjected to post-processing. Post-processing of the roller bearings40may include heat treatment at about 1500 degrees F., followed by quenching and machining or grinding of the precise dimensions into the roller bearings40according to the knowledge of those skilled in the art. The relatively lightweight material composition of the roller bearings40dramatically reduces the weight of the roller bearings40, whereas the relatively heavyweight material composition of the outer layer57(FIG. 15A) enhances the wear resistance characteristics of the roller bearings40.

Referring next toFIGS. 16-19Aof the drawings, sequential fabrication of the outer race37of the roller bearing assembly36(FIG. 13) according to an illustrative embodiment of the methods of fabricating reduced weight components is illustrated. As illustrated inFIG. 16, a tubular outer race core60having a core wall61traversed by a core bore62is provided. The outer race core60may be a relatively lightweight material such as titanium, for example and without limitation. A non-limiting example of a material which is suitable for the outer race core60may include a titanium/aluminum/vanadium alloy such as Ti6Al-4V containing 90% Ti, 6% aluminum and 4% vanadium.

As illustrated inFIG. 17, multiple outer races37may be cut from the outer race core60typically using conventional machining techniques. The adjacent outer races37may remain connected to each other in end-to-end relationship.

As illustrated inFIGS. 18 and 19A, a base layer54may initially be applied over the contact surfaces37aof each outer race37. In some embodiments, the base layer54may be applied over the contact surfaces37aby loosely spraying a particulate material of which the base layer54will be made on the contact surfaces37ausing conventional thermal spraying techniques known by those skilled in the art, as illustrated inFIG. 18, as the connected outer races37are typically rotated to facilitate uniform application. The base layer54may include a mixture having the relatively lightweight material of which the outer race core60(FIG. 16) is made and at least one relatively heavyweight material, with a higher proportion of the relatively lightweight material than the relatively heavyweight material. In some embodiments, the base layer54may include a mixture of about 95% by weight titanium and about 5% by weight 52100 steel, for example and without limitation.

As further illustrated inFIG. 19A, at least one mixed layer56may be applied over the base layer54. In some embodiments, the mixed layer56may be applied over the base layer54by loosely spraying the particulate mixed layer material on the base layer54using conventional thermal spraying techniques, as illustrated inFIG. 18. The mixed layer56may include a mixture having the relatively lightweight material of which the roller bearing core44is made and at least one relatively heavyweight material. One or more of the mixed layers56closest to the base layer54may have a higher proportion of the relatively lightweight material than the relatively heavyweight material. Successive mixed layers56may have gradually progressively higher proportions of the relatively heavyweight material than preceding mixed layers56which are closer to the base layer54. In some embodiments, one or more of the mixed layers56may include hybrid particles26(FIG. 11C). In some non-limiting embodiments, the base layer54and the transition layer or layers56may have a total thickness of up to about 100,000s of an inch. An outer layer57may in like manner be applied over the outermost mixed layer56. The outer layer57may include the relatively heavyweight material without the relatively lightweight material to increase the contact resistance of the contact surface37aof each outer race37.

As illustrated inFIG. 19, the sprayed outer races37may be placed in a can70having a can interior71. In some embodiments, the can70may include an annular can interior71between two concentric inner and outer sealed steel tubes70aand70b, respectively. A filler powder74may next be applied over the outer layer57on the outer races37. The filler powder74may fill the can interior71between the interior surface of the can70and the outer races37. In some embodiments, the filler powder74may be applied over the outer layer57using conventional thermal spraying techniques. In some embodiments, the filler powder74may include mild steel powder, for example and without limitation. After application of the filler powder74, the can interior71of the can70may be hermetically sealed such as by welding, for example and without limitation.

The outer races37may next be subjected to HIP (Hot Isostatic Press) processing. The HIP processing may be carried out in a standard or conventional HIP furnace known by those skilled in the art. Exemplary process parameters for the HIP processing may include HIP temperatures of typically from about 1700 to 2100 degrees F. and HIP pressures of from about 15,000 to about 30,000 psi applied to the can70. The HIP pressure may be applied to the can46using argon or other inert gas as is known by those skilled in the art. Accordingly, the HIP processing presses the can70against the filler powder74, the outer layer57, the mixed layer(s)56, the base layer54and the roller bearing core44. After the HIP processing is completed, the can70may be removed from the outer races37using machine cutting tools or other suitable techniques known by those skilled in the art. In some embodiments, the can may be thermally sprayed and consolidated using mechanical forces or impacting according to the knowledge of those skilled in the art prior to HIP processing.

After fabrication is completed, the outer races37may be subjected to post-processing. Post-processing of the outer races37may include heat treatment at about 1500 degrees F., followed by quenching and machining or grinding of the precise dimensions into the outer races37according to the knowledge of those skilled in the art. The relatively lightweight material composition of the outer races37dramatically reduces the weight of the outer races37, whereas the relatively heavyweight material composition of the outer layer57enhances the wear resistance characteristics of the outer races37in the roller bearing assembly36(FIG. 13).

Referring next toFIGS. 20 and 20Aof the drawings, sequential fabrication of the inner race38of the roller bearing assembly36(FIG. 13) according to an illustrative embodiment of the methods of fabricating reduced weight components is illustrated. Accordingly, multiple inner races38may be cut from the core wall77of a tubular inner race core76typically using conventional machining techniques. The adjacent inner races38may remain connected to each other in end-to-end relationship.

As illustrated inFIG. 20A, a base layer54, at least one mixed layer56and an outer layer57may be sequentially applied to the contact surfaces38aof each inner race38. Deposition of the base layer54, the mixed layer(s) and the outer layer57on the contact surfaces38aand post-processing of the inner race38may be carried out using the same materials and techniques which were heretofore described with respect to fabrication of the outer races37inFIGS. 16-19A. The relatively lightweight material composition of the inner races38dramatically reduces the weight of the inner races38, whereas the relatively heavyweight material composition of the outer layer57enhances the wear resistance characteristics of the inner races38in the roller bearing assembly36(FIG. 13).

Referring next toFIGS. 21-25of the drawings, an exemplary pinion gear101which is fabricated according to an illustrative embodiment of the methods of fabricating reduced weight components is illustrated. The pinion gear101may include an annular gear core102provided on an elongated gear shaft108. Gear teeth104are provided in the outer surface of the gear core102. As will be hereinafter further described, the gear core102is fabricated of a relatively lightweight material such as titanium or titanium-aluminum alloy, for example and without limitation. The gear teeth104are formed at least in part of a material which has higher wear resistance than the relatively lightweight material of which the gear core102is made and may be heavier in weight than the material of the gear core102. The relatively heavyweight material imparts substantial wear resistance to the gear teeth104.

Referring next toFIGS. 22-25of the drawings, sequential fabrication of the pinion gear101according to an illustrative embodiment of the methods of fabricating reduced weight components is illustrated. As illustrated inFIG. 22, a gear core106is provided. In some embodiments, the gear core106may include an elongated bar stock of a relatively lightweight material such as titanium, for example and without limitation. In other embodiments, alternative materials for the gear core106may be used according to different applications of the methods. The gear core106may have a front core surface106aand a rear core surface106b.

As illustrated inFIG. 23, gear teeth undercuts110and preliminary gear teeth104awhich will ultimately form the gear teeth104(FIG. 1) in the gear core102are cut in the front core surface106ato form a reverse image mold for spraying. The gear teeth undercuts110and preliminary gear teeth104amay be made in the front core surface106ausing conventional machining techniques known by those skilled in the art. Each gear teeth undercut110has undercut surfaces111. Preliminary gear teeth104amay extend between adjacent gear teeth undercuts110.

As illustrated inFIG. 24, applied layers119are applied over the undercut surfaces111of the gear teeth undercuts110and the preliminary gear teeth104a. As illustrated inFIG. 24A, the applied layers119may include a base layer114which is applied over the undercut surfaces111of the gear teeth undercuts110and the preliminary gear teeth104a, at least one mixed layer116which is applied over the base layer114and an outer layer117which is applied over the mixed layer(s)116. In some embodiments, the applied layers119may be applied by loosely spraying a particulate material using conventional thermal spraying techniques known by those skilled in the art. The base layer114may include a mixture having the relatively lightweight material of which the gear core106is made and at least one relatively heavyweight material of which the outer layer117will be made, with a higher proportion of the relatively lightweight material than the relatively heavyweight material. In some embodiments, the base layer114may include titanium, for example and without limitation.

The mixed layer(s)116may be applied over the base layer114by loosely spraying the particulate mixed layer material on the base layer114using conventional thermal spraying techniques. The mixed layer(s)116may include a mixture having the relatively lightweight material of which the gear core106is made and at least one relatively heavyweight material of which the outer layer117will be made. One or more of the mixed layers116closest to the base layer114may have a higher proportion of the relatively lightweight material than the relatively heavyweight material, with a higher proportion of the relatively lightweight material than is provided in the base layer114. Successive mixed layers116may have gradually progressively higher proportions of the relatively heavyweight material than preceding mixed layers116which are closer to the base layer114. In some embodiments, one or more of the mixed layers116may include hybrid particles26(FIG. 11C). In some non-limiting embodiments, the base layer114and the mixed layer(s)116may have a total thickness of up to about 100,000s of an inch. The outer layer117may in like manner be applied over the outermost mixed layer(s)116. The outer layer117may include the relatively heavyweight material without the relatively lightweight material.

As illustrated inFIG. 25, a can120may be placed over the outer layer117of the applied layers119. In some embodiments, the can120may include a steel plate, for example and without limitation. The can120may be hermetically sealed against the applied layers119such as by welding, for example and without limitation, according to the knowledge of those skilled in the art.

The gear core106with the can120in place may be subjected to HIP (Hot Isostatic Press) processing. Exemplary process parameters for the HIP processing24may include HIP temperatures of typically from about 1700 to 2100 degrees F. and HIP pressures of from about 15,000 to about 30,000 psi applied to the can120. The HIP pressure may be applied to the can120using argon or other inert gas as is known by those skilled in the art. Accordingly, the HIP processing presses the can120against the applied layers119, removing voids in the applied layers119and forming the gear teeth104which are substantially free of voids and metallurgically fused to the gear core106. After the HIP processing is completed, the can20may be removed from the underlying gear teeth104using machine cutting tools or other suitable techniques known by those skilled in the art. In some embodiments, the can120may be thermally sprayed and consolidated using mechanical forces or impacting according to the knowledge of those skilled in the art prior to HIP processing.

After fabrication is completed, the pinion gear101may be subjected to post-processing. Post-processing of the pinion gear101may include heat treatment at about 1500 degrees F., followed by quenching and machining or grinding of the precise gear dimensions into the gear teeth104according to the knowledge of those skilled in the art.

Referring next toFIGS. 26-32of the drawings, fabrication of a pinion gear201(FIG. 31) according to an alternative illustrative embodiment of the methods of fabricating reduced weight components is illustrated. The pinion gear201fabricated according to the method illustrated inFIGS. 26-32may include a stabilizing shell, stiffener, skeletal framework or structure280which enhances the torsional resistance or rigidity of the gear teeth204in the gear core202of the finished pinion gear201. As illustrated inFIG. 26, a gear shaft208is provided. The gear shaft208may include a relatively lightweight material such as titanium, for example and without limitation. The stabilizing structure280may be placed on the gear shaft208. The stabilizing structure280may be fabricated of a relatively heavyweight material having a higher torsional resistance than that of the relatively lightweight material of the gear shaft208. In some embodiments, the stabilizing structure280may include steel, for example and without limitation. Accordingly, the stabilizing structure280may be particularly advantageous in structurally enhancing titanium alloy as the relatively lightweight material since titanium alloy has roughly one-half the rigidity of steel.

The stabilizing structure280may have any structure or design which will strengthen or enhance the torsional resistance of the gear teeth204in the gear core202of the finished pinion gear201. Accordingly, as illustrated inFIGS. 26 and 27, in some embodiments, the stabilizing structure280may include at least one stabilizing disk282. In the example illustrated inFIGS. 26-32, the stabilizing structure280includes a pair of stabilizing disks282which may be placed on the gear shaft208in spaced-apart relationship to each other. Each stabilizing disk282may include a disk body283through which extends a shaft opening284that accommodates the gear shaft208. Disk teeth285may extend from an outer surface of the disk body283. The disk teeth285may generally correspond in position and number to the gear teeth204which will be fabricated in the gear core202of the finished pinion gear201.

As illustrated inFIG. 28, a can220may next be placed over the stabilizing structure280. In some embodiments, a can221may also be placed over the exposed portion of the gear shaft208. In some embodiments, the can220,221may include a steel plate, for example and without limitation. In some embodiments, the can220may be thermally sprayed and consolidated using mechanical forces or impacting according to the knowledge of those skilled in the art.

As illustrated inFIGS. 29, 30 and 33, applied layers219(FIG. 33) may next be sequentially applied between the can220and the stabilizing disks282of the stabilizing structure280. As illustrated inFIG. 33, the applied layers219may include a base layer214which is applied over the gear shaft208and the disk teeth285of the stabilizing disk282, at least one mixed layer216which is applied over the base layer214and an outer layer217which is applied over the mixed layer(s)216. In some embodiments, the applied layers219may include a powder layer218which may include the relatively heavyweight material of which the outer layer217is made. In some embodiments, the applied layers219may be applied loosely spraying a particulate material using conventional thermal spraying techniques known by those skilled in the art. The base layer214may include a mixture having the relatively lightweight material of which the gear shaft208is made and at least one relatively heavyweight material of which the outer layer217will be made, with a higher proportion of the relatively lightweight material than the relatively heavyweight material. In some embodiments, the base layer214may include titanium, for example and without limitation.

The mixed layer(s)216may be applied over the base layer214by loosely spraying the particulate mixed layer material on the base layer214using conventional thermal spraying techniques. The mixed layer(s)216may include a mixture having the relatively lightweight material of which the gear shaft208is made and at least one relatively heavyweight material of which the outer layer217will be made. One or more of the mixed layers216closest to the base layer214may have a higher proportion of the relatively lightweight material than the relatively heavyweight material, with a higher proportion of the relatively heavyweight material than is provided in the base layer214. Successive mixed layers216may have gradually progressively higher proportions of the relatively heavyweight material than preceding mixed layers216which are closer to the base layer214. In some embodiments, one or more of the mixed layers216may include hybrid particles26(FIG. 11C). In some non-limiting embodiments, the base layer214and the mixed layer(s)216may have a total thickness of up to about 100,000s of an inch. The outer layer217may in like manner be applied over the outermost mixed layer(s)216. The outer layer217may include the relatively heavyweight material without the relatively lightweight material.

After application of the applied layers219, the can220may be hermetically sealed against the applied layers219such as by welding, for example and without limitation. The applied layers219with the can220in place may be subjected to HIP (Hot Isostatic Press) processing. Exemplary process parameters for the HIP processing may include HIP temperatures of typically from about 1700 to 2100 degrees F. and HIP pressures of from about 15,000 to about 30,000 psi applied to the can220. The HIP pressure may be applied to the can220using argon or other inert gas as is known by those skilled in the art. Accordingly, the HIP processing presses the can220against the applied layers219, removing voids in the applied layers219. After the HIP processing is completed, the can220may be removed from the applied layers219using machine cutting tools or other suitable techniques known by those skilled in the art. The consolidated powder layer218may be cut away, leaving the outer layer217of the remaining consolidated applied layers219exposed on the surfaces of the gear teeth204.

After fabrication is completed, the pinion gear201may be subjected to post-processing. Post-processing of the pinion gear201may include heat treatment at about 1500 degrees F., followed by quenching and machining or grinding of the precise gear dimensions into the gear teeth204according to the knowledge of those skilled in the art. As illustrated inFIGS. 31 and 32, the disk teeth285(FIG. 27) of the stabilizing disks282underlie and define the pattern of the gear teeth204in the gear core202. In application of the pinion gear201, the stabilizing disks282reduce elastic bending of the gear teeth285whereas the relatively heavyweight material of the outer layer217of the applied layers219enhances the contact resistance and bending strength of the gear teeth204.

The methods which were heretofore described with respect toFIGS. 1-33of the drawings illustrate non-limiting examples of reduced weight components which can be fabricated using methods of fabricating reduced weight components according to the disclosure.FIGS. 34-36, which will be hereinafter described, generally illustrate methods which can be used to fabricate a wide variety of reduced weight components according to the disclosure.

Referring next toFIG. 34of the drawings, an illustrative embodiment of the methods of fabricating reduced weight components is generally indicated by reference numeral300. The method300may be used to fabricate components which generally have a central bore or opening that may accommodate a shaft on which the component is mounted, for example and without limitation. Non-limiting examples of components which can be fabricated according to the method300include gears such as ring gears, spur gears, pinion gears, worm gears and planetary ring gears or flywheels.

At block302, a sacrificial component blank having a blank surface is provided. In some embodiments, the sacrificial component blank may include steel, for example and without limitation. At block304, a reverse image of component features is undercut in the blank surface of the sacrificial component blank. At block306, an outer layer may be applied to the undercut blank surface. The outer layer may include a relatively heavyweight material or a mixture having the relatively heavyweight material and at least one relatively lightweight material of which the component body or core will be made, with a higher proportion of the relatively heavyweight material than the relatively lightweight material. In some embodiments, the outer layer may include steel, a mixture of steel and titanium, for example and without limitation.

At block308, at least one mixed layer is applied over the outer layer. The mixed layer may include a mixture having the relatively heavyweight material of which the final contact surfaces (the outer layer) of the component will be made (typically steel or steel alloy) and at least one relatively lightweight material of which the component core will be made (typically titanium). One or more of the mixed layers closest to the outer layer may have a higher proportion of the relatively heavyweight material than the relatively lightweight material, with a higher proportion of the relatively lightweight material than is provided in the outer layer. Successive mixed layers may have gradually progressively higher proportions of the relatively lightweight material than preceding mixed layers which are closer to the outer layer. In some embodiments, the mixed layer may include hybrid particles each having a particle core and a particle coating on the particle core, as was heretofore described with respect toFIG. 11C.

At block310, a base layer may be applied over the mixed layer or layers. The base layer may include the relatively lightweight material of which the component core will be made without the relatively heavyweight material. In some embodiments, the base layer may include titanium, for example and without limitation. The outer layer, the mixed layer(s) and the base layer may be loosely applied sequentially by thermal spraying or other techniques which are known by those skilled in the art and suitable for the purpose.

At block312, a can may be positioned over the base layer. In some embodiments, the can may be thermally sprayed over the base layer and consolidated using mechanical forces or impacting according to the knowledge of those skilled in the art. At block314, a powder layer may be applied over the base layer. The powder layer may include the relatively lightweight material which will form the component core. In some embodiments, the powder layer may include a titanium/aluminum/vanadium alloy, for example and without limitation. The powder layer may be applied by loose thermal spraying or other techniques which are known by those skilled in the art and suitable for the purpose.

At block316, the can may be hermetically sealed. At block318, a component core may be formed by consolidating the powder layer. In some embodiments, consolidation of the powder layer to form the component core may be carried out using HIP (Hot Isostatic Press) processing. In other embodiments, consolidation of the powder layer may be carried out using alternative processes which are known by those skilled in the art and suitable for the purpose. At block320, the sacrificial component blank may be cut away from the base layer. The outer layer which was applied at block306forms the contact surface of the component. At block322, post-processing may be carried out. Post-processing may include heat treatment quenching and machining or grinding of precise dimensions of the component features according to the knowledge of those skilled in the art. The relatively lightweight material composition of the component core dramatically reduces the weight of the component, whereas the relatively heavyweight material composition of the now exposed outer layer on the component features enhances the wear resistance characteristics of the component features.

Referring next toFIG. 35of the drawings, a flow diagram of a slightly modified illustrative embodiment of the methods of fabricating reduced weight components is generally indicated by reference numeral400. The method400may be used to fabricate solid components which generally lack a central bore or other opening. Non-limiting examples of components which can be fabricated according to the method400include U-joints, roller bearings, races, fasteners, camshafts, crankshafts, linkages, connectors, splined shafts, suspension components, couplings, engine valve components, pump components and shafts.

At block402, a component core having a core surface is provided. The component core may include a relatively lightweight material such as titanium, for example and without limitation. At block404, component features may be undercut in the core surface of the component core. At block406, a base layer may be applied over the undercut core surface. The base layer may include a mixture having the relatively lightweight material of which the component core is made and at least one relatively heavyweight material of which the final layer of the component features will be made, with a higher proportion of the relatively lightweight material than the relatively heavyweight material. In some embodiments, the base layer may include a mixture of a relatively lightweight material such as titanium and a relatively heavyweight material such as steel, for example and without limitation.

At block408, at least one mixed layer is applied over the base layer. The mixed layer may include a mixture having the relatively lightweight material of which the component core is made and at least one relatively heavyweight material of which the component surface will be made. One or more of the mixed layers closest to the base layer may have a higher proportion of the relatively lightweight material than the relatively heavyweight material. Successive mixed layers may have gradually progressively higher proportions of the relatively heavyweight material than preceding mixed layers which are closer to the base layer. In some embodiments, the mixed layer may include hybrid particles each having a particle core and a particle coating on the particle core, as was heretofore described with respect toFIG. 11C.

At block410, an outer layer may be applied over the mixed layer or layers. The outer layer may include the relatively heavyweight material without the relatively lightweight material. In some embodiments, the outer layer may include steel, for example and without limitation. The base layer, the mixed layer(s) and the outer layer may be applied by loose thermal spraying or other techniques which are known by those skilled in the art and suitable for the purpose.

At block412, a can may be positioned over the outer layer and hermetically sealed. In some embodiments, the can may be thermally sprayed and consolidated using mechanical forces or impacting according to the knowledge of those skilled in the art. At block414, the base layer, the mixed layer(s) and the outer layer may be consolidated. In some embodiments, consolidation of the layers may be carried out using HIP (Hot Isostatic Press) processing. In other embodiments, consolidation of the layers may be carried out using alternative processes which are known by those skilled in the art and suitable for the purpose. At block416, post-processing may be carried out. Post-processing may include heat treatment quenching and machining or grinding of precise dimensions of the component features according to the knowledge of those skilled in the art. The relatively lightweight material composition of the component dramatically reduces the weight of the component, whereas the relatively heavyweight material composition of the outer layer on the component features enhances the wear resistance characteristics of the component features.

Referring next toFIG. 36of the drawings, a flow diagram of a slight modification of an illustrative embodiment of the methods of fabricating reduced weight components is generally indicated by reference numeral500. The method500may be used to fabricate solid components which generally lack a central bore or other opening and require a stabilizing structure to stabilize or reduce elastic bending of component features such as gear teeth or splines, for example and without limitation.

At block502, a component shaft is provided. The component shaft may include a relatively lightweight material such as titanium, for example and without limitation. At block504, a stabilizing structure is placed on the component shaft. The stabilizing structure may include a relatively heavyweight material which is characterized by structural rigidity such as steel or steel alloy, for example and without limitation. At block506, a can may be placed over the stabilizing structure. In some embodiments, the can may be thermally sprayed and consolidated using mechanical forces or impacting according to the knowledge of those skilled in the art. At block508, a base layer may be applied over the stabilizing structure and the component shaft. The base layer may include a mixture having a relatively lightweight material and at least one relatively heavyweight material of which the final layer of the component features will be made, with a higher proportion of the relatively lightweight material than the relatively heavyweight material. In some embodiments, the base layer may include a mixture of a relatively lightweight material such as titanium and a relatively heavyweight material such as steel, for example and without limitation with a higher proportion of the relatively lightweight material.

At block510, at least one mixed layer is applied over the base layer. The mixed layer may include a mixture having the relatively lightweight material of which the component blank is made and at least one relatively heavyweight material of which the outer layer on the component features will be made. One or more of the mixed layers closest to the base layer may have a higher proportion of the relatively lightweight material than the relatively heavyweight material, with a higher proportion of the relatively heavyweight material than is provided in the base layer. Successive mixed layers may have gradually progressively higher proportions of the relatively heavyweight material than preceding mixed layers which are closer to the base layer. In some embodiments, the mixed layer may include hybrid particles each having a particle core and a particle coating on the particle core, as was heretofore described with respect toFIG. 11C.

At block512, an outer layer may be applied over the mixed layer or layers. The outer layer may include the relatively heavyweight material without the relatively lightweight material. In some embodiments, the outer layer may include steel, for example and without limitation. The base layer, the mixed layer(s) and the outer layer may be applied by loose thermal spraying or other techniques which are known by those skilled in the art and suitable for the purpose.

At block514, a powder layer may be applied over the outer layer. The powder layer may include the relatively heavyweight material of which the outer layer512is made. At block516, the base layer, the mixed layer(s), the outer layer and the powdered layer may be consolidated. In some embodiments, consolidation of the layers may be carried out using HIP (Hot Isostatic Press) processing. In other embodiments, consolidation of the layers may be carried out using alternative processes which are known by those skilled in the art and suitable for the purpose. At block518, the component features may be cut in the consolidated powder layer and outer layer with the outer layer remaining in place over the component features. At block520, post-processing may be carried out. Post-processing may include heat treatment quenching and machining or grinding of precise dimensions of the component features according to the knowledge of those skilled in the art. The relatively lightweight material composition of the component dramatically reduces the weight of the component, whereas the relatively heavyweight material composition of the outer layer on the component features enhances the wear resistance characteristics of the component features.

While illustrative embodiments of the disclosure have been described above, it will be recognized and understood that various modifications can be made and the appended claims are intended to cover all such modifications which may fall within the spirit and scope of the disclosure.