[Changes in the metallic phase at the metal-ceramic margin of baked alloys of nonprecious metals].

Five base metal alloys were investigated to determine if phase changes in the alloy microstructure occurred as a result of the porcelain baking procedure. It was found that during the oxidation treatments concentration changes in the alloy surface led to a depletion of certain elements in four of the alloys investigated. It was also found that phase changes could occur in a region 20 micrometers wide next to the alloy surface. Phase changes and alloying element depletion occurs as a result of the oxidation treatments prior to the fusion of porcelain and not as a result of or during porcelain fusion.