Microstructure and hardness of Co-Cr-Ti alloys for dental castings

Effect of adding titanium on the microstructure and hardness of as-cast Co-Cr base dental alloys have been investigated with the purpose to determine the region of their optimal characteristics. Twelve samples of Co-Cr-Ti alloys with increasing titanium content (4 to 12 at.%), which were prepared by arc-melting technique in argon atmosphere, revealed similar two-phases dendritic microstructure. It consist of dendrites and interdendritic region, which differ in crystal structures (fcc, hcp) and slightly in compositions. The hardness of alloys increases significantly with titanium and chromium content. The as-cast alloys with smaller titanium content (samples 3 to 5) have promising features for dental applications, because their hardness values are in good agreement with that of similar commercial dental alloys.