Abstract
Various heat treatments were carried out on dental Au-Ag-Pd-Cu alloy.Tensile tests and dynamic fracture toughness tests were then carried out on the heat-treated alloys.The influence of heat-treatment conditions on tensile and impact fracture characteristics were then investigated based on the test results.Tensile strength and 0.2% proof stress increased with increased solutionizing temperature.Tensile strength and 0.2% proof stress increased with increased aging temperature in aged materials.On the contrary, elongation decreased with increased solutionizing temperature in as-solutionized materials.Dynamic fracture toughness value tended to increase with increased solutionizing temperature except in some cases similar to the trend in strength values.Increased strength contributes more markedly to dynamic fracture toughness compared to the loss due to decreased ductility.The dynamic fracture toughness value was greater in as-solutionized materials than in aged materials.Heat-treatment with a solutionizing temperature of 1073K was judged to provide superior results when strength, toughness and ductility were taken into account.In as-solutionized materials, the heat treatment process where air cooling was performed after solutionizing was superior because the cooling process was more convenient and aging process can be omitted.
