Al ALLOY CAST IMPELLER FOR COMPRESSOR AND PROCESS FOR PRODUCING SAME

摘要

Provided is an aluminum alloy cast impeller for compressors that shows stable high-temperature strength at operating temperatures of about 200° C., and that has excellent productivity. The Al alloy cast impeller for compressors is configured to include a boss part, a plurality of blade parts, and a disc part. The Al alloy cast impeller for compressors is formed of an Al alloy cast that contains Cu: 1.4 to 3.2 mass % (hereinafter, “%”), Mg: 1.0 to 2.0%, Ni: 0.5 to 2.0%, Fe: 0.5 to 2.0%, and Ti: 0.01 to 0.35%. The boss part, the blade parts, and the disc part have secondary dendrite arm spacings of 20 to 50 μm, 10 to 35 μm, and 5 to 25 μm, respectively, and satisfy the relationship Amax>Bmax>Cmax, where Amax, Bmax, and Cmax are the maximum values of the secondary dendrite arm spacings of the boss part, the blade parts, and the disc part, respectively. The Al alloy cast impeller for compressors has a 0.2% proof stress value of 260 MPa or more at 200° C. A method for producing the aluminum alloy cast impeller for compressors is also disclosed.

主权项

1. An Al alloy cast impeller for compressors comprising a boss part, a plurality of blade parts, and a disc part,
wherein the Al alloy casting comprises an Al alloy that contains Cu: 1.4 to 3.2 mass %, Mg: 1.0 to 2.0 mass %, Ni: 0.5 to 2.0 mass %, Fe: 0.5 to 2.0 mass %, and Ti: 0.01 to 0.35 mass %, the balance of Al and unavoidable impurities, wherein the boss part has a secondary dendrite arm spacing of 20 to 50 μm, the blade parts have a secondary dendrite arm spacing of 10 to 35 μm, and the disc part has a secondary dendrite arm spacing of 5 to 25 μm, wherein the boss part, the blade parts, and the disc part satisfy the relationship Amax>Bmax>Cmax, where Amax is the maximum value of the secondary dendrite arm spacing of the boss part, Bmax is the maximum value of the secondary dendrite arm spacing of the blade parts, and Cmax is the maximum value of the secondary dendrite arm spacing of the disc part, and wherein the Al alloy cast impeller for compressors has a 0.2% proof stress value of 260 MPa or more at 200° C.