| 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. |
