Doped gold alloy

Abstract

The invention relates to an alloy of gold of at least 14 carats, characterized in containing 10 to 20,000, preferably 100 to 1000 ppm Zn, 10 to 20,000, preferably 100 to 1000 ppm Ga, 10 to 20,000 preferably 100 to 1000 ppm Ta, 10 to 10,000, preferably 90 to 950 ppm Pt, and 10 to 5000, preferably 5 to 100 ppm Ru, a cast object made from said alloy, a method for production thereof and use thereof for production of jewelry by the lost wax method.

1 . A gold alloy of at least 14 carats, wherein it containing as dopants, by weight, from 10 to 20,000, preferably from 100 to 1000 ppm Zn, from 10 to 20,000, preferably from 100 to 1000 ppm Ga, from 10 to 20,000, preferably from 100 to 1000 ppm Ta, from 10 to 10,000, preferably from 90 to 950, ppm Pt and from 10 to 5000, preferably from 5 to 100 ppm Ru.  
   
   
       2 . The alloy as claimed in  claim 1 , which is a 14 carat alloy based on gold, silver and copper, selected from the group consisting of a yellow gold alloy having, expressed by weight, 58-59% Au, 24-28% Ag and 13-17% Cu, and a red gold alloy having, expressed by weight, 58-59% Au, 7-11% Ag and 30-34% Cu.  
   
   
       3 . The alloy as claimed in  claim 1 , which is an 18 carat alloy based on gold, silver and copper, selected from the group consisting of a yellow gold alloy having, expressed by weight, 75-76% Au, 10-14% Ag and 10-14% Cu, a pale yellow gold alloy having, expressed by weight, 75-76% Au, 14-18% Ag and 7-11% Cu, a pink gold alloy having, expressed by weight, 75-76% Au, 7-11% Ag and 14-18% Cu, and a red gold alloy having, expressed by weight, 75-76% Au, 2-6% Ag and 18-22% Cu.  
   
   
       4 . The alloy as claimed in  claim 1 , which is a 22 carat alloy based on gold, silver and copper, selected from the group consisting of a yellow gold alloy having, expressed by weight, 91-92% Au, 3-7% Ag and 1-5% Cu, and a red gold alloy having, expressed by weight, 91-92% Au, 0-2% Ag and 6-10% Cu.  
   
   
       5 . The alloy as claimed in  claim 1 , which is a fine gold alloy having, expressed by weight, 99-99.9% Au, 0-1% Cu, from 10 to 10,000 ppm Zn, from 10 to 10,000 ppm Ga, from 10 to 10,000 ppm Ta, from 10 to 10,000 ppm Pt and from 10 to 5000 ppm Ru.  
   
   
       6 . The alloy as claimed in  claim 1 , which is an 18 carat gray gold alloy having, expressed by weight, 75-76% Au, 8-12% Cu, 0-4% In and 11-15% Pd.  
   
   
       7 . The alloy as claimed in  claim 1 , which is a 14 carat gray gold alloy having, expressed by weight, 58-59% Au, 14-18% Ag, 12-16% Pd and 6-10% Cu.  
   
   
       8 . The alloy as claimed in  claim 1  which, instead of the specified Ta weight ratio, has an identical weight ratio of an element selected from the group consisting of Ti, Zr and Nb.  
   
   
       9 . A cast object comprising an alloy as claimed in  claim 1 .  
   
   
       10 . A method for manufacturing a gold alloy comprising: casting a gold alloy of at least 14 carats, containing as dopants, by weight, from 10 to 20,000, preferably from 100 to 1000 ppm Zn, from 10 to 20,000, preferably from 100 to 1000 ppm Ga, from 10 to 20,000, preferable from 100 to 1000 ppm Ta, from 10 to 10,000, preferably from 90 to 950, ppm Pt and from 10 to 5000, preferably from 5 to 100 ppm Ru either in a pure state or in an alloy state, under an inert atmosphere.  
   
   
       11 . The method as claimed in  claim 10 , wherein the alloy is formed by continuous casting.  
   
   
       12 . Use of an alloy as claimed in of  claim 1  in the manufacture of jewelry by investment casting.