The phase transformations in three different types of commercial dental alloys for porcelain bonding, a high-gold content alloy, a low-gold content alloy and a palladium-base alloy, were studied by measurement of electrical resistivity, X-ray diffraction and EPMA. Three distinguishable phase transformations and associated microstructural changes were observed in these alloys during the constant rate slow-cooling from 1000°C to room temperature. An ordered Ll2 type structure of (Pt0.67Pd0.33)3Sn or Pt2PdSn phase was induced at the grain boundary in the high-gold content alloy. Phase separation was found in the low-gold alloy. An fct structure of (Pd0.67Ag0.33)3(In0.6Sn0.4 based on Pd3In was formed as a blade-like precipitate within the grain interior of the palladium-base alloy.
All Science Journal Classification (ASJC) codes
- Ceramics and Composites