抄録
The average weight of powder metallurgy (PM) parts per car was 6.6kg in 1995 in Japan. This report describes tasks for increasing the average weight and the state of development of raw powders as it relates to those tasks. (1) To improve basic properties of parts, new powders for control of microstructure of PM material by alloying and heat-treatment, , and densification by new compacting and sintering methods are continuing to be developed. (2) For higher value-added PM parts, pre-mixed segregation-free powders have been developed. (2)-1 New raw powders to stabilize feeding into the cavity of the forming die and a new compacting technique are expected, and will contribute to improved stability of PM part quality and dimensional accuracy. (2)-2 Powder with AC magnetic properties is under development to add functional performance to PM parts. (3) To reduce production costs by improving productivity, powders which will make it possible to omit machining, heat-treatment, and similar processes after sintering are being developed.
