Papers by Keyword: Powder Metal

Abstract: In casting of hyper-eutectic Al-Si alloys, primary Si grains often grow, which deteriorates mechanical properties of the castings. In this study, an attempt was made to obtain hyper-eutectic Al-Si alloy parts without coarse primary Si grains by taking another route of sinter-forging. The sinter-forging taken up here is semisolid one. In this sinter-forging, a green compact billet of hyper-eutectic Al-25mass% Si alloy powder is rapidly resistance-heated into a semisolid state to promote the sintering and then upset-forged into a disc shape, and the performance was examined by paying special attention to the behavior of primary Si grains in the relation to the resistance heating condition.

Abstract: New P/M lubricant formulations implement micron-sized (“micronized”) cellulose particles (MCP) to create MCP-enhanced lubricants. Surprising increases in green strength, up to 70% for iron and even higher for stainless steel are obtained with standard transverse rupture bars shapes made with 0.75 wt-% additive concentrations in iron (MPIF F-0000) and 316L stainless steel powders in comparison with the same parts made under the same conditions with industry standard lubricantbinders of zinc stearate, ethylene-bis-stearamide (EBS), and oxidized polyolefin (OP) wax. Two specific forms of new MCP materials are used in these tests: micronized cotton fibers (MCF), and micronized starch particles (MSP). The findings support expectations of significantly increased process yields for green parts and related production cost savings.