Abstract
Fatigue tests in artificial saliva were carried out on variously heat-treated dental Ag-Pd-Cu-Au (12 mass% Au) type alloys. The effects of microstructures and artificial saliva on fatigue characteristics of dental Ag-Pd-Cu-Au type alloys are discussed, and fatigue fracture mechanism in artificial saliva is also analyzed. Fatigue strength in artificial saliva of the alloy after each heat treatment showed nealy the same result as that in air in the region showing a low cycle fatigue life. However, fatigue strength of aged alloy is, in particular, lower in artificial saliva than in air in high cycle fatigue life region. For the alloy contaning a large volume fraction of β phase, that is, for the aged alloy, corrosion may occur preferentially at the interface between the β phase and matrix. Then, the stress concentration at this site may be remarkable. Fatigue strength of the alloy in artificial saliva is reduced by the β phase.
