Effects of casting temperature on some properties of Co-Cr-Mo dental casting alloys.

The castability of three Co-Cr-Mo-C alloys, taken as the percentage of a grid pattern that was filled by metal, increased almost linearly from less than 10% to nearly 100% when the casting temperature was increased by 150 degrees C. The surface finish became poor only at the highest applied casting temperature (1635 degrees C). The ductility was significantly reduced by increasing the volume fraction of eutectic hard particles containing carbides. These particles cracked in a direction vertical to the stress in tensile tests, initiating a brittle failure. They also affected the work-hardening rate, and their volume fraction increased with the content of C and Cr.