| 摘要 |
A low-carat, corrosion-resistant gold alloy is provided whose outer layer does not become blackened after casting. The alloy is used as a casting alloy for tooth replacement and for jewellery products, or as a contact alloy for use in electrical apparatus. It is composed essentially of gold, palladium and silver, indium being present instead of copper, which is contained in conventional alloys of this type, and zinc or tin components, which are necessary as deoxidising agents, being present. Copper components have hitherto been regarded as desirable in view of the castability and the mechanical strength of the alloy, but this resulted in the surface or outer layer of the alloy being blackened, which made it necessary to wash off the blackened oxide films using a sharp acidic detergent, in particular, for aesthetic considerations. The indium provided instead of copper provides the necessary mechanical properties and, at the same time, an aesthetically attractive silver to grey surface, and makes the washing with sharp acids superfluous.
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