Forged Metal Powder Gears.

A powder metallurgy PM forging technology for production of critical Army automotive gears was established. The variables investigated during the program included powder compositions, forging temperature, die temperature, preform configuration, press type and a combined wrought-PM process composite for producing forged gears. The selected process employed 4600 prealloyed powder and sintering and forging temperatures of 2200F. A simplified preform configuration involving 3 dimensional metal flow in a closed die system was used to produce forged pinions. An extrude-forge process was employed to produce the gears. The properties of the PM forged material were shown to be comparable to wrought material of similar composition. Cost analysis indicated that the process was capable of providing significant cost reductions achieved through material savings and reduction or elimination of machining operations.