Experimental Study of the Deformation Mechanisms in Textured Alpha-titanium Alloy Sheets
Résumé
The initial microstructure, texture and deformation micromechanisms activated during uniaxial tensile tests of a T40 titanium alloy sheet is investigated experimentally. X-rays diffraction and transmission electron microscopy (TEM) in-situ tensile tests as well as post-mortem TEM observations were carried out. Texture measurements performed by X-rays diffraction indicate a typical strong cold rolling texture with basal poles (0001) tilted by+/-35 degrees from the normal direction towards the transverse direction. As the tensile tests performed along the transverse direction (TD) and the rolling direction (RD) revealed a strong anisotropy and a strain rate sensitivity of the pure titanium sheets, in-situ TEM tensile tests (under angles of 0 degrees and 90 degrees with respect to the RD) were carried out to understand the micromechanisms, which control the deformation depending on the loading direction. The dislocation glide systems were determined as a function of the grain orientations in the textured T40.