Analysis of plastic deformation and residual elastic strain in a titanium alloy using synchrotron x-ray diffraction

This paper presents the results of a study of elastoplastic deformation of titanium alloy Ti-6Al-4V subjected to four point bending prior to residual elastic strain measurements by high energy synchrotron diffraction. Both white-beam and monochromatic x-rays were used at the SRS Station 16.3 in order to record diffraction patterns as a function of beam position across the sample. This allowed the comparison between the two techniques to be readily made. Residual (elastic) strain was calculated as a function of position across the sample, based on different reflections of hcp titanium. Inelastic bending analysis was used to extract the plastic strains. The results demonstrate that (i) the level of plastic deformation can be deduced from the x-ray diffraction profile, (ii) the asymmetry of the material response to plastic deformation in tension and compression can be identified and (iii) differences in the behaviour of different grain groups can be seen. © 2005 IOP Publishing Ltd.