Powder-Extrusion of Rapidly-Solidified Aluminum Alloy Powder and The Applications

P/M Al alloy, made from incorporating rapidly-solidified Al alloy powders and then hot working, for example extrusion or forging, possesses properties such as low thermal expansion coefficient, excellent wear resistance and high strength. Therefore, in Japan, technologies for powder-extrusion and powder-forging of Al alloy powders have been developed over ten years, and applied to many components, such as rotors and vanes of compressors for car air conditioners, orbital scrolls of compressors for room air conditioners, cylinder liners of motor cycle engines, and so on. In this report the applications, such as rotors and vances, are presented, and the industrial technologies for near-net-shape extrusion with good dimensional accuracy and without cracks or defects are described. Moreover, cylinder liners made of particle-dispersed composites with fine alumina and graphite, which have recently been manufactured in mass production, are discussed in detail.