The present invention relates to a method for manufacturing a sintered bearing having a bearing surface that forms a bearing gap with a shaft to be supported, in its inner periphery. This manufacturing method includes: a compacting step P2 of compacting a base powder containing a diffusion alloyed powder 11 prepared by partially diffusing a copper powder in an iron powder as a main material, a low-melting-point metal powder 14, and a solid lubricant to obtain a green compact, and a sintering step P3 of sintering the green compact 4 to obtain a sintered compact 4.

It has been found that duplex monolithic parts can be manufactured in high volume at low cost by using powder metal technology to mold and sinter an inner component of the part into an outer component of the part. This technique reduces the cost of manufacturing intricate metal products by taking advantage of the attributes of powder metal technology in making the inner component of the part. The outer component of the part can be wrought machined, stamped or forged, or made by double press double sinter or forging a powder metal component of the part. In any case, this technique can beneficially be used in making a wide variety of toroid parts, such as gears, clutches, sprags, bearing races, one-way diodes, and the like.

A functionally graded carbide body (400) can include a group 5 metal carbide substrate having a bulk composition region (410) that contains at least 70 wt % of a rhombohedral -phase carbide. A -phase-rich region (420) having a -phase-rich composition can be at a surface (430) of the substrate, and a phase composition gradient region (440) can transition from the -phase-rich composition region at the surface to the bulk composition region at a gradient depth (450) below the surface.

A functionally graded carbide body (400) can include a group 5 metal carbide substrate having a bulk composition region (410) that contains at least 70 wt % of a rhombohedral -phase carbide. A -phase-rich region (420) having a -phase-rich composition can be at a surface (430) of the substrate, and a phase composition gradient region (440) can transition from the -phase-rich composition region at the surface to the bulk composition region at a gradient depth (450) below the surface.

It has been found that metal parts having rough surfaces can be manufactured by (1) compacting a metal powder under high pressure in a mold to make a green part, wherein at least one face of the mold is roughened by electrical discharge machining to have an R.sub.a of 10 to 200 micro-inches, as measured with a profilometer having a stylus tip, (2) heating the green metal part to a temperature of at least 1500 F. to sinter the green metal part to produce the metal part having at least one rough surface, wherein the rough surface has an R.sub.a which is within the range of 10 to 200 micro-inches, as measured with a profilometer having a chisel tip, and (3) optionally, buffing, classifying, deburring and/or washing the metal part. This method can be beneficially used in manufacturing clutch plates, pressure plates, and cam shaft sprockets.

It has been found that metal parts having rough surfaces can be manufactured by (1) compacting a metal powder under high pressure in a mold to make a green part, wherein at least one face of the mold is roughened by electrical discharge machining to have an R.sub.a of 10 to 200 micro-inches, as measured with a profilometer having a stylus tip, (2) heating the green metal part to a temperature of at least 1500 F. to sinter the green metal part to produce the metal part having at least one rough surface, wherein the rough surface has an R.sub.a which is within the range of 10 to 200 micro-inches, as measured with a profilometer having a chisel tip, and (3) optionally, buffing, classifying, deburring and/or washing the metal part. This method can be beneficially used in manufacturing clutch plates, pressure plates, and cam shaft sprockets.

A method of fabricating an article includes providing an arrangement of loose nanowires and bonding the loose nanowires in the presence of carbon together into a unitary cellular structure.

A method of fabricating an article includes providing an arrangement of loose nanowires and bonding the loose nanowires in the presence of carbon together into a unitary cellular structure.

The present invention provides a low cost pre-alloyed iron based powder which has high compressibility, capable of rendering a compacted and sintered component high green density, (GD), and high sintered density, (SD). Also, a method or process for producing components, especially gears, including compaction of powder mixture containing the pre-alloyed iron-based powder, sintering of the compacted component, Low Pressure carburizing, (LPC), High Pressure Gas Quenching, (HPGQ), and tempering, is provided. In one embodiment, the process includes high temperature sintering. Other aspects of the present invention include a powder mixture containing the pre-alloyed iron based powder and components produced by the new process from the powder mixture. Such carburized components exhibit a hard surface combined with a softer and tougher core, necessary properties for e.g. automotive gears subjected to harsh environment.

The present invention provides a low cost pre-alloyed iron based powder which has high compressibility, capable of rendering a compacted and sintered component high green density, (GD), and high sintered density, (SD). Also, a method or process for producing components, especially gears, including compaction of powder mixture containing the pre-alloyed iron-based powder, sintering of the compacted component, Low Pressure carburizing, (LPC), High Pressure Gas Quenching, (HPGQ), and tempering, is provided. In one embodiment, the process includes high temperature sintering. Other aspects of the present invention include a powder mixture containing the pre-alloyed iron based powder and components produced by the new process from the powder mixture. Such carburized components exhibit a hard surface combined with a softer and tougher core, necessary properties for e.g. automotive gears subjected to harsh environment.