Department of Mechanical Engineering, University of Tehran, Tehran, Iran.
Parallel tubular channel angular pressing (PTCAP) process is a novel recently developed severe plastic deformation technique for fabrication of ultrafine grained (UFG) metallic tubes. This new process consists of two half cycles and is affected by several parameters such as channel angles, deformation ratio and curvature angles. In this paper, the effects of these parameters on the plastic deformation behavior, imposed strain, strain homogeneity and the process load were investigated using finite element method (FEM). The results indicated that an increase in the channel angle leads to a decrease in the imposed strain at the end of both half cycles of PTCAP process. Investigation on the effects of the curvature angles showed that better strain homogeneity is achieved in lower curvature angles. Also, minimum required process load and the best strain homogeneity could be obtained in the curvature angle equal to zero. Study on the deformation ratio (K) revealed that the best and worse strain homogeneity could be achieved in K values equal to 0.6 and 1 respectively. From the point of view of better strain homogeneity and needing lower process loads, it could be concluded that lower K value (0.6 t0) leads to best strain homogeneity and lowest process load.