The replacement of Ni as well as the reduction of the Pd content is the major focus of ongoing research work on white gold alloys all over the world. Several alternative alloy systems, based on Mn, Fe or Pt, for example, have already been proposed and reviewed in recent years. The present paper reports on the development of a new alloy system which has not yet been investigated. The results have been worked out in a research project funded by the European Commission, in cooperation with several industrial partners. The compositions and properties of the newly developed alloys will be discussed and compared to those of the already-known alternatives. In particular, the new alloys possess excellent corrosion resistance in combination with promising color properties, which are superior to the known alternatives. Due to the new alloy constituents, however, the alloys also possess an increased reactivity with atmosphere, crucibles and investment material. First results of on-field tests at the industrial partners will be reported and will allow for a judgment of whether the advantages of the new alloys can be expected to level off the efforts related with the increased demands for treatment of the material.

Author: Dr. Jörg Fischer-Bühner, Dieter Ott