Research of Metal Flow Behavior during Extrusion with Active Friction

Using numerical simulation and experiment, the metal flow behavior mechanical mechanisms in the extrusion process with active friction were investigated. The characteristic variables, second invariant of the stress deviator J ₂ and the Lode’s coefficient μ were employed to partition the deformation region. It is shown that no metal flow interface occurred at the container bottom in the extrusion with active friction and the dead zone disappeared completely. The strain types of the material in the plastic deformation area decreased from three types into a single type of tension, and the homogeneity of metal deformation as well as metal flow was greatly improved. It was also indicted that the active friction was beneficial to the extrusion process and the promotion of product quality. After contrasting the result of experiment and the simulation, the displacement and the load were well correlated on both values and trends.