Computer Simulation Of Grain Orientation In Pure Ti Processed By Equal Channel Angular Pressing

Deformation occurs in the given slip systems and twin systems for pure Ti processed by equal channel angular pressing(ECAP) which effecting on physical properties and mechanical properties of pure Ti due to preferred orientation. Pure Ti was successfully processed by ECAP up to two passes with a die of 90° via route C at room temperature. Based on the crystal plasticity finite element model and the commercial software ABAQUS, the texture evolution simulation was carried out successfully for pure Ti processed by the single-pass and two passes ECAP with channel angle of 90°. X-ray diffraction(XRD) was employed to investigate the texture of pure Ti after ECAP. The experimental and simulated texture data were converted into polar figures and orientation distribution function(ODF) using the MTEX tool in Matlab software.Combining simulation and experiment to analyze grain orientation changes on the ECAPed pure Ti, the main results are as follows: The initial texture of pure Ti disappears gradually and prismatic texture and pyramidal texture form after ECAP. The simulated polar figures after single-pass ECAP are basically consistent with the experimental results, expect in polar density which was caused by not taking friction and twinning into consideration in the simulation process on the basis of the reasonable constitutive equation. Pyramidal texture gradually disappears, prismatic texture counterclockwise rotates to parallel to pure shear deformation texture, and new basic texture forms during the simulation process of two passes ECAP. However, experimental results show only the prismatic texture having a large polar density forms. The difference attributes to that the grain shape has not been considered in Taylor model. Finally Schmid factor of the ECAP deformation texture for pure Ti main slip system was calculated, it is concluded that with the increase of deformation path, deformation texture during tensile deformation makes in the number of slip system close to the soft orientation increasing, more conducive to the occurrence of plastic deformation.