Characteristic of intermetallic phases in cast dental CoCrMo alloy

Abstract

Abstract Apart from chromium and molybdenum, casting alloys of cobalt usually contain also up to 0.35 % of carbon. With significant content of carbon, presence of carbide-forming alloying elements results in creating carbide phases. These alloys are characterised by dendritic structure of solid solution of chromium and molybdenum in cobalt with interdendritically precipitated carbides. Because of high chromium content, dominating are M23C6-type carbides, but chromium-rich carbides can be also of M7C3 and M3C2-types. The other elements in the alloy result in creating M6C and MC-type carbides. In the case of low carbon content, creating carbides and forming intermetallic phases based on the alloying elements and cobalt become limited. The presented research was aimed at characterising structure of the cobalt-based dental alloy containing trace quantity of carbon. Characterised were intermetallic phases hardening the alloy. Microscopic examinations using light microscopy, SEM and TEM were carried out. Chemical microanalysis of the precipitates using X-ray analyser EDS was performed, as well as phase analysis using selected area electron diffraction