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

Abstract

Abstract 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 σ 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 χ phase. The calculated lattice parameters of the intermetallic phase precipitated in the 3.0Si and 5.0Si alloys correlated well with those of Co 5 Cr 3 Si 2 phase.