| 摘要 |
<p>A method is provided for method for making a gold alloy, including the steps of: (a) forming a master alloy consisting essentially of constituents of said gold alloy and inevitable impurities (e.g. an AgCu alloy, AgCuZn alloy, CuZn alloy or AgZn alloy optionally containing one or more incidental ingredients selected from Ni, Fe and Si.) ; and (b) melting together the master alloy and gold to form the desired gold alloy; wherein the step of forming the master alloy includes adding boron as a compound selecting from the group consisting of alkyl boron compounds, boron hydrides, boron halides metal borohydrides metal borohalides, and mixtures thereof. The boron compound may be added to the master alloy in the gas, liquid or solid phase, and in the latter embodiment to minimize evaporation of the boron on contact with the precursor alloy melt, the boron compound may be wrapped in a metal foil formed from constituents of the precious metal alloy or master alloy. The cast precious metal allo y or master alloy has been found to have a reduced number of hard spots when compared to conventional casting methods.</p> |
