Abstract
Fracture toughness of commercial Ag-Pd-Cu-Au dental alloy, where the precipitation of β phase was controlled systematically, was evaluated. The relationship between fracture toughness and volume fraction or size of precipitated β phase was quantitatively investigated in this study. Volume fraction and diameter of precipitated β phase increased as aging time and aging temperature increased. Fracture toughness of Ag-Pd-Cu-Au alloy decreased with increasing volume fraction of precipitated β phase under aging conditions when the diameter of precipitated β phase is constant. While the fracture toughness of Ag-Pd-Cu-Au alloy increases with the increasing diameter of precipitated β phase in under aged conditions when volume fraction of precipitated β phase is constant. The fracture toughness increases with increasing width of slip area observed on the side surface of the specimen. The fracture toughness increased with the degree of crack deflection.
