Micro-compression of high oxygen doped single-crystal titanium along different orientations

To explore the deformation mechanism of alpha-Ti with high oxygen doping, micro-pillars of single crystal with orientations of near 0 degrees, 45 degrees, and 90 degrees inclined to c-axis were fabricated via focused ion beam (FIB) milling from a high oxygen content commercial purity Ti (CP-Ti). The micro-pillars were loaded under quasi-static compression. Post-mortem analysis reveals that only prismatic slip activated for 45 degrees and 90 degrees oriented samples with their critical resolved shear stress (CRSS) values of about 457 MPa and 596 MPa, and only {10-11} < c+a > the first order pyramidal slip activated on the 0 degrees sample with a CRSS of around 1019 MPa. The results suggest that the oxygen addition remarkably reduces the CRSS ratio between non-prismatic and prismatic slips of alpha-Ti. In addition, the results indicate that the Schmid law may not be applicable for alpha-Ti single crystal at micro-size level.