Finite element analysis of plastic deformation of CP-Ti by multi-pass equal channel angular extrusion at medium hot-working temperature

The plastic deformation of commercially pure (CP) titanium by multi-pass equal channel angular extrusion (ECAE), at medium hot-working temperature, was simulated using finite element method. The effect of ECAE deformation was to uniformly deform the middle billet by simple shear and to induce a side shift of un-deformed and un-moved billet-ends so as to preserve its original shape during deformation. Unlike the single ECAE pass, where the corner gap is important, it was the repetitive billet-end side-shift of less-deformed billet-ends which are responsible for the development of the non-uniformly deformed zone in the multi-pass ECAE processing via route A. The deformation zone was however little affected in the multi-pass EACE processing via route C, because of the alternate sense of billet-end side-shift. The simulation well predicted the inclination angles of elongated-grain in the multi-pass ECAE deformation.