Slip and twinning deformation mechanisms in titanium alloys in tension and compression

This proposal is part of the ongoing ERC PhD project “Size effect on the mechanical properties of polycrystalline materials in oxidizing and protective atmosphere”. The motivation of the project is to distinguish difference in strain distribution/grain orientation spread in “surface” grains and “core” grains of titanium-based materials and correlate these distributions to size effects in the presence of a free surface. Tensile and compression tests were already performed and surface EBSD characterisations were done to identify the anisotropic response of the material in tension (planar slip) versus compression (deformation twinning). Moreover, we propose an analysis of the effect of oxygen on the strain localisation and how it modifies the twinning behaviour of titanium. Our ambition is to extend and complement HR-EBSD and HR-DIC using SEM or LSCM with volumetric characterisations using a combination of diffraction contrast tomography (DCT) and topotomography (TT).