3D FEM Simulation of Multipass ECAP Ti-50.8%Ni at Various Temperatures

Abstract

Equal channel angular pressing (ECAP) is widely studied for its potential to produce ultra-fine grained (UFG) structure in TiNi shape memory alloys (SMA). In the present work, the effect of multipass ECAP parameters on the deformation behavior and strain distribution was investigated, at various deformation temperatures through different planes in the ECAPed billet. Three-dimensional (3D) geometric model with corner angle 120◦ was designed by finite element method (FEM) software for ECAPing Ti-50.8%Ni by route Bc in DEFORM-3D software. Two methods were used to quantify deformation homogeneity through various planes in the processed billet, including strain standard deviation (SSD) and inhomogenity index (Ci). The simulation results demonstrate that by increasing ECAP passes, the cumulative average strain can increase and obtain UFG structure, but heterogeneity still exist across planes. In addition, temperature has a remarkable effect on homogeneity distribution .As well as Ci exhibits good results for multipass ECAP at various deformation temperature compared to SSD value.