Finite Element Simulation And Application Of Equal Channel Angular Extrusion

In this dissertation, finite element modeling of Equal Channel Angular Extrusion (ECAE) was conducted using the DEFORM-3D code to obtain a better understanding of the plastic deformation behavior of T2-copper and pure aluminum during ECAE in terms of the values and distributions of stress, strain and strain rate. The results are as follows: 1. Friction conditions deeply affect the deformation behavior of the billet during ECAE. Low friction conditions carry out a partial filling, creating a "dead zone" in the outside corner of the die. On the other hand, high friction conditions assure a complete filling of the outside corner, but the "flash" is appeared at the head and the rear of the billet. 2. The variation tendency of effective stress is complied with the following laws: the effective stress curve rapidly reaches a peak point followed by a sudden drop. Afterwards, it rises to the maximum again and keeps for a time, and then falls down gradually. The stress state is compressive in the most part of the deformation zone, but the tensile stress is predicted on the top surface of the billet adjacent to the exit channel of the die,...