Research on the numerical simulation of liquid-infiltration-extrusion process for composites based on the rigid-viscoplastic FEM

As a new forming method, the liquid-infiltration-extrusion process has become one of the most important methods for forming discontinuously fiber or particle reinforced composites developed in recent years. This forming process combines the merits of the liquid metal infiltration and semi-solid extrusion. However, the simulation is complicated as the forming process involving the solidification under pressure and large deformation. The process is simulated based on the coupled thermal-mechanical rigid-viscoplastic FEM against the typical problems in the process simulation in this paper. The distribution for the stress, strain, extrusion velocity and temperature in the forming processes were gained from the simulation. In addition, the effects of process parameters such as die preheating, pouring temperature, infiltration time and forming speed on deformation process were investigated. It was concluded that the friction coefficient, die semi-angle and initial process parameters were the most primary variables which affect the deformation process. Long pressure-keeping time, large friction coefficient and small forming die semi-angle all can lead to great deformation force. The numerical simulation results have a good agreement with their experimental ones. Hence, the process parameters can be selected rationally to improve the quality of forming products based on the results.