On microstructural homogenization and mechanical properties optimization of biomedical Co-Cr-Mo alloy additively manufactured by using electron beam melting

摘要: Abstract The electron beam melting (EBM), a layer-by-layer additive manufacturing (AM) technique, has been recently utilized for fabricating metallic components with complex shape and geometry. However, the inhomogeneity in microstructures mechanical properties are main drawbacks constraining serviceability of EBM-built parts. In present study, we found remarkable microstructural along build direction Co-based alloy, owing to competitive grain growth subsequent isothermal γ-fcc → e-hcp phase transformation, which affects corresponding tensile significantly. Then, succeeded eliminating inhomogeneities, modifying structures refining sizes via comprehensive post-production heat treatment regimes, provides valuable implication improving reliabilities AM-built metals alloys. alloy can be selectively transformed into predominant e or γ by regime, grains were refined 1/10 initial repeated treatment. Finally, investigated fracture behaviors before after each strain-induced martensitic transformation is major deformation mode phase, meanwhile formation stripped at {111}γ habit planes contributed good combination strength ductility. Nevertheless, was deformed mainly (0001)e 2 ¯ 0 >e basal {1 1 00 }e prismatic slip systems, exhibiting very limited ductility strength. addition, act as secondary hardening factor samples consisting dual γ/e leading non-uniform behavior.