Abstract
A fatigue test was carried out on heat-treated dental Ag-Pd-Cu-Au(12mass%Au)alloys in air. The effect of microstructure on fatigue characteristics was investigated. In the water quenched alloys, the fatigue strength increased with increasing solutionizing temperature in the low-cycle fatigue region. While the fatigue strength decreased with increasing solutionizing temperature in the high-cycle fatigue region. In aged alloys, the fatigue strength increased due to precipitation strengthening caused by the precipitation of the β phase in the low-cycle fatigue region, while the fatigue strength markedly decreased due to the precipitated β phase, which led to a fracture site in the high-cycle fatigue regions. The fatigue strength of the alloy with a large volume fraction of the α1 phase was excellent due to the work hardening of α1 phase in the high-cycle fatigue region. However, the volume fraction of the β phase should be taken into account in order to improve the absolute value of fatigue strength.
