The influence of volumetric dilution on the strain induced γ → ɛ martensitic transformation in GTAW processed Co–Cr–Mo alloy

Mechanical properties of cobalt base alloys are greatly affected by strain induced martensitic transformation (SIT). The present study aims to investigate the influence of volumetric dilution on the SIT and work-hardening in GTAW processed Co–Cr–Mo alloy (Stellite 21) during wear test. The worn surfaces were studied by XRD, SEM and microhardness tester. The results showed that the development of SIT—ɛ phase was strongly influenced by iron content, whereas the work-hardening was less sensitive to dilution. The volume fraction of ɛ phase was increased by decrease in volumetric dilution.