Cold-rolling behavior of biomedical Ni-free Co-Cr-Mo alloys: Role of strain-induced ε martensite and its intersecting phenomena.

摘要: Ni-free Co-Cr-Mo alloys are some of the most difficult-to-work metallic materials used commonly in biomedical applications. Since difficulty plastically deforming them limits their use, an in-depth understanding plastic deformability is crucial importance for both academic and practical purposes. In this study, microstructural evolution a Co-29Cr-6Mo-0.2N (mass%) alloy during cold rolling was investigated. Further, its work-hardening behavior discussed while focusing on strain-induced face-centered cubic (fcc) γ→hexagonal close-packed (hcp) e martensitic transformation (SIMT). The planar dislocation slip subsequent SIMT occurred even initial stage deformation process owing to low stability γ-phase contributed work hardening behavior. However, amount SIMTed e-phase did not explain overall variation rolling. It found that intersecting e-plates enhanced local strain then produced fine domain-like microstructures at intersections. Consequently, degree reduced deformation, resulting exhibiting two-stage results obtained study suggest interaction between e-martensites, ultimately relaxation mechanism, significant importance; therefore, aspect should be addressed detail; atomic structures γ-matrix/e-martensite interfaces, phenomenon transfer slipping itself needed elucidated further increasing such alloys.