摘要
A metastableβTi alloy was additively manufactured by laser powder bed fusion(LPBF).Tensile testing along the build direction of the as-LPBF material(LPBF-0°)revealed signifcant work softening immediately following yielding with no uniform deformation.By contrast,substantial work hardening and uniform elongation well over 10%were achieved perpendicular to the build direction(LPBF-90°).Similar effects were obtained in the build direction after super transus heat treatment(LPBF-0°+HT)although the strength was slightly lowered.In addition,the yield drop phenomenon observed in both orientations of the as-LPBF materials disappeared after HT.The enhanced work hardening ability,and thus ductility,can be attributed to increased interactions of slip bands/slip bands owing to additional{112}<111>slip systems becoming operative in LPBF-0°+HT and LPBF-90°while LPBF-0°was dominated by{110}<111>only.The other variations after HT may be related to the coarsening of grain structure and removal of specifc substructures in the as-LPBF microstructure.
基金
supported by the Australian Research Council(No.DP190103557)
the University of Melbourne(No.ECRG20)。