Forged aluminum alloy spiral parts and method of fabrication thereof

Abstract

Spiral parts, such as orbiting and fixed scroll plates having involute wraps, for use in scroll compressors, the parts having low coefficient of thermal expansion and high tensile strength and Young's modulus, are formed by combining a self-lubricating power into aluminum raw material powder prior to compression and forging. As an alternative to and in conjunction with the foregoing, temperatures during preform heating and in the die for forging are controlled to be in respective ranges of 300.degree. to 500.degree. C. and 150.degree. to 500.degree. C. Aluminum alloy fine powder preferably has a particle diameter no larger than 350 .mu.m. The self-lubricating powder preferably forms 1 to 25% of the mix by volume, and contains at least one member selected from the group consisting of graphite, BN, and MoS.sub.2. The aluminum raw material powder may contain at least one element selected from the group consisting of Cu, Mg, and Si, or a kind of compound particles from the group consisting of oxides, nitrides, borides, and carbides of Fe, Al, Mg, Ti, Zr, and Si.

Dependencies are inferred from the claim text.