Characterization of intermetallic phase in as-cast Si-doped Co-Cr-Mo alloys

This research aims to investigate the effects of Si concentrations on the microstructure and formation of the intermetallic phase of Co-Cr-Mo-xSi alloys. The Si concentration (x) was varied between 0.1, 0.5, 1.0, 3.0 and 5.0 wt%. The microstructure and intermetallic phase of the solution heat-treated Co-Cr-Mo alloys were characterized using SEM-EDX, XRD and TEM. The microstructure analysis revealed that Si concentration played a role in the evolution of intermetallic phase precipitating in Co-Cr-Mo alloys. Two types of intermetallic phased were found in the Si-doped Co-Cr-Mo alloys. The sigma phase was identified in the alloys containing Si between 0.1-1.0 wt% while the increase in Si (3.0-5.0Si) contributed to the formation of the. phase. The calculated lattice parameters of the intermetallic phase precipitated in the 3.0Si and 5.0Si alloys correlated well with those of Co5Cr3Si2 phase.