Veterans Administration Cooperative Studies Project No. 147/242. Part VII: The mechanical properties of metal ceramic alloys as cast and after simulated porcelain firing.

Comparison of mechanical properties of seven metal ceramic alloys in as-cast and heat-treated conditions resulted in significant differences. Tested alloys included one Au-Pd (control), three palladium-based, and three nickel-based alloys. Mechanical properties included strength, elongation, modulus, and microhardness. Twenty-four tensile bars were cast for each alloy. Twelve of the 24 bars for each alloy were randomly selected for heat treatment by the Ceramco technique. After heat treatment the Au-Pd alloy became stronger and harder and showed an increased elongation. The effects of heat treatment on the strength of the palladium-based alloys were variable, showing a decrease in hardness and an increase in elongation. The nickel-based alloys were weakened by the heat treatment and showed a decrease in hardness and an increase in elongation. Heat treatment did not significantly affect the modulus of any of the tested alloys.