Abstract: A method of fabricating clutch races for one-way clutch mechanisms includes compacting and sintering a ferrous-based powder metal to near-net shape to produce a core density of between about 6.8 to 7.6 g/cc and a race surface that is near-net shape. The cam surface is cold worked in a manner that locally increases the density at the surface to develop a highly densified layer of essentially fully densified material and with a final surface finish that, after heat treatment, is ready to use in a one-way clutch application without further working. Both the inner and outer clutch races of one-way clutch mechanisms can be formed in this fashion and yield races that exhibit excellent strength, toughness, fatigue strength and wear resistance.

Abstract: An iron-based sintered powder metal article for cam lobe and other high temperature, high wear applications requiring excellent net-shape stability during sintering comprises a powder metal mixture consisting essentially of, by weight, 0.5-3.0% Mo, b-6.5% Cr, 1-5% V, and the balance Fe and impurities. These articles also have a carburized case having 0.7-1.2% C by weight. Following carburization of the case, the articles are quenched to form a martensitic matrix having a network of disbursed carbides of Cr and V. The resulting sintered articles have good mechanical strength and wear resistance and possess excellent machineability and dimensional stability.

Abstract: The invention provides a method and apparatus for densifying the teeth of a powder metal preform gear. The die includes an aperture for receiving a body of the gear and a plurality of grooves for receiving the teeth of the gear. The grooves have a length and a variable width along the length. The grooves narrow tangentially relative to the aperture. The powder metal preform gear is urged through the die and the teeth are plastically and elastically deformed at a relatively narrow portion of the groove. After passing through the narrow portion of the groove and being compressed, the teeth can at least partially recover. The grooves defined by the die can be helical for forming a helical groove.

Abstract: The invention provides a method and apparatus for densifying the teeth of a powder metal preform gear. The die includes an aperture for receiving a body of the gear and a plurality of grooves for receiving the teeth of the gear. The grooves have a length and a variable width along the length. The grooves narrow tangentially relative to the aperture. The powder metal preform gear is urged through the die and the teeth are plastically and elastically deformed at a relatively narrow portion of the groove. After passing through the narrow portion of the groove and being compressed, the teeth can at least partially recover. The grooves defined by the die can be helical for forming a helical groove.

Abstract: A ferrous sintered valve seat material is made of mixed powders comprising a sinter-hardenable phase and a finely dispersed carbide phase. The powder mixture comprises a sinter-hardening prealloyed powder forming 75 to 90 wt. % of the mixture and a tool steel powder with finely dispersed carbides forming 5 to 25% of the mixture. Machinability additives of MnS, CaF2 or MoS2 types are added in an amount of 1 to 5 wt. %. Improved thermal conductivity is obtained by infiltrating the compact with Cu up to 25 wt. %.

Abstract: An iron-based sintered powder metal mixture for valve guides, valve seat inserts and other high temperature, high wear applications requiring excellent net-shape stability during sintering comprises a powder metal mixture consisting essentially of 0.5-2.0 wt. % of fine, soluble graphite which goes into solution in the elemental iron matrix, 0.5-2.5 wt. % stable graphite which remains as free graphite in the sintered structure, 0.5-3.0 MoS2, which reacts with 1.0-5.0 wt. % copper to drive a sintering reaction at relatively low sintering temperatures of between 1030—1150° C. The resulting sintered particles have good mechanical strength and wear resistance and possess excellent machineability and dimensional stability.

Abstract: A ferrous sintered valve seat material is made of mixed powders comprising a sinter-hardenable phase and a finely dispersed carbide phase. The powder mixture comprises a sinter-hardening prealloyed powder forming 75 to 90 wt. % of the mixture and a tool steel powder with finely dispersed carbides forming 5 to 25% of the mixture. Machinability additives of MnS, CaF2 or MoS2types are added in an amount of 1 to 5 wt. %. Improved thermal conductivity is obtained by infiltrating the compact with Cu up to 25 wt. %.