Influence of gd addition on the structure and properties of Au-Ni and Au−Ni−Cr alloys

The influence of Gd additions on the microstructure and properties of Au-Ni and Au-Ni-Cr alloys are reported. The alloys remain single phase solid solution at Gd contents of −0.1wt%, but at contents τ 0.1%, two phases structures are formed, consisting of (Au) and a low melting point intermetallic compound containing Gd. Trace additions of Gd refine the grain size, increase strength and the recrystallization temperature, but without detriment to the good electric conductivity of these alloys. The wear life of potentiometer windings made of gold alloys containing Gd are at least one order of magnitude higher than those made in the Gd-free gold alloys. The design of gold alloys for precise electrical contact and resistance materials by conventional and microalloying is discussed.