MAGNESIUM-ALLOY MEMBER, COMPRESSOR FOR USE IN AIR CONDITIONER, AND METHOD FOR MANUFACTURING MAGNESIUM-ALLOY MEMBER

摘要

The present invention provides a magnesium alloy member and a method for manufacturing a magnesium alloy member capable of achieving a mechanical strength and a high-temperature fatigue strength sufficient to apply them to mechanical parts of a compressor for automotive air conditioners. The invention also provides a compressor for air conditioners using, as a mechanical part thereof, a magnesium alloy equipped with a necessary mechanical strength and high-temperature fatigue strength. More specifically, a magnesium alloy member is formed by subjecting a cast material of a magnesium alloy containing, on the basis of mass%, from 0.3% to 10% calcium (Ca), from 0.2% to 15% aluminum (Al), and from 0.05% to 1.5% manganese (Mn), and containing calcium (Ca) and aluminum (Al) at a calcium/aluminum mass ratio of from 0.6 to 1.7, with the balance being magnesium (Mg) and inevitable impurities to plastic working (extrusion processing) at from 250°C to 500°C. This makes it possible to obtain a magnesium alloy member having a room-temperature 0.2% proof stress of 300 MPa or more and a 150°C fatigue strength of 100 MPa or greater. The magnesium alloy member used for the formation of mechanical parts of a compressor for automotive air conditioners contributes to a reduction in the weight of the compressor.