| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a copper alloy superior in machinability achieved by adding Si to a Cu-Zn based alloy, and superior particularly in mechanical properties and castability, in which crystal grains can be refined reliably; and a cast formed of the copper alloy. <P>SOLUTION: The copper alloy has a composition including≥69 and≤88 mass% of Cu;≥2 and≤3.8 mass% of Si;≥0.001 and≤0.5 mass% of P;≥1 and≤100 mass ppm of S;≥10 and≤2,000 mass ppm of Zr,≥5 and≤2,000 mass ppm of Mg; and the balance of Zn and unavoidable impurities, and the mass ratio of Zr to Mg, that is, Zr/Mg satisfies a relation: 0.05≤Zr/Mg≤5.0. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
