Lattice strain evolution during tensile and compressive loading of CP Ti

The micromechanics of textured Grade 1 commercially pure titanium are examined using neutron diffraction, self-consistent modelling and microscopy. It is found that twinning produces greater hardening than slip, that the residual lattice strains produced in the (0 0 0 2) are on the order of 0.001, and that both compression and tension twins are observed for both tensile and compression straining. The critical resolved shear stresses found are consistent with the macroscopic flow curves, lattice strains and textures produced, but are much lower than those found using uncorrected focused ion beam-milled micromechanical testing. The twins observed in axial compression were thicker than those found when compressing in the hoop direction, which is taken to imply that axial compression produced a greater number of twinning dislocations that could result in twin thickening. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.