| 摘要 |
PURPOSE:To obtain the titled German silver having high resistance to stress corrosion cracking and satisfactory die castability by specifying the composition of an alloy obtd. by adding Al, Sn and Si to Cu, Zn and Ni as principal components. CONSTITUTION:This German silver for die casting consists of, by weight, 25- 40% Zn, 5-20% Ni, 0.2-2% Si, 0.2-2% Sn, <=2% Al and the balance Cu with impurities. The German silver has high resistance to stress corrosion cracking, a low m.p. and satisfactory die castability and prolongs the life of dies. When the German silver is melted, it flows well, has a high rate of charge, and gives a product free from defects such as blow holes. In the composition of the German silver, Zn prevents a rise in the m.p., Ni provides resistance to stress corrosion cracking, and Si is effective in deoxidation and in reducing the m.p. and improving the flowability. Sn improves the chargeability, and Al produces the same effects as Si and improves the quality of a product.
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