3D Finite Element Modeling of Molybdenum Equal Channel Angular Pressing

Equal-channel angular pressing (ECAP) is a manufacturing process in which a material is subjected to a severe plastic shear strain with negligible change in the cross-sectional dimensions of the work-piece. Due to the severe plastic deformation, the ECAP process was investigated experimentally mainly on ductile materials such as Cu-99% and Al-4%Cu. Application of ECAP to harder metals (such as CP-Ti or Mo) imposes several problems due to the elevated temperature involved, cracks that may appear in the material and the large forces required. Furthermore, several cycles of the ECAP are required to obtain a uniform residual strain field in the workpiece. To optimize and gain scientific insight into the ECAP process of a Mo workpiece, a combined experimental–numerical investigation was conducted. A three dimensional finite element analysis (FEA) that simulates an ECAP BC4 process of hard metal at elevated temperature was performed. Both quantitative (final simulated geometry was compared to the shape of the workpiece after ECAP) qualitative (hardness and grain size were compared to effective-strain) methods were used for FE results validation.