Properties of Low Karat Gold Alloys Part 1. Mechanical Properties of the Alloys Containing 5 mass% Pd

Abstract

As alternative alloys to Ag−Pd−Cu−Au system alloys, low karat gold alloys consisting of 47.25〜22.33mass% Au −30.70〜48.62mass%Ag−12〜19mass%Cu−2mass% Pt−5 mass% Pd − 2mass% Zn−1 mass% In−0.05 mass% Ir were made. The heat treatment effects, Vickers hardness, tensile 　strength, elongation, and fatigue strength were investigated for the specjmens made by centrifugal casting with a natural gas−oxygen torch. It was found from the results that all experimental alloys had potential for heat treatment. Within the components of the experimental alloys, Vickers hardness, tellsile strength, and fatigue strength increased with the decrease of the gold content, and were similar or much greater than those of commercially available Ag−Pd−Cu−Au system alloys. On the contrary, the elongation increased with the decrease of the gold content. We found that experimental alloys containing over 30 mass% gold content were favorable as alternatives tothe Ag−Pd−Cu−Au system alloys