The FEM Simulation Of The Liquid Infiltration-Extrusion Process For Composites

The liquid infiltration-extrusion technology, as a new forming method which includes the liquid forging and the solid extrusion, has been developed in recent years. The process in essence is that after liquid metal is infiltrated into the fiber perform under pressure, high pressure is directly applied to it so that the melted metal is to be crystallized and solidified under pressure, and then undergoes large plastic deformation at the liquid-solid state or the state just solidified. By means of this technology, shape products of metal-matrix composites can be formed in the single process.In this paper, the temperature fields during liquid infiltration extrusion of composites are simulated with the FEM, the seepage fields of liquid metal are simulated with the FDM. Both the temperature fields and the seepage fields are coupled, the temperature variation curves, infiltration front process curves and velocity variation curves with time are obtained. The results indicate that the fiber radius, infiltration pressure, liquid metal viscosity coefficient and the volume fraction of perform affect the infiltration velocity of liquid metal and the infiltration process. The temperature fields, stress-strain fields for the forming process are simulated with the rigid-viscoplastic direct coupled FEM. During the temperature fields, the results indicate that the processing parameters such as the extrusion velocity, casting temperature, perform preheating temperature, die preheating temperature and so on are important for the temperature fields besides the dwell time. They are must be in concordance each other to the deforming zone is in the quasi-solid state, and the stable semi-solid extrusion is implemented. During the deforming fields, the hyperbolic sine thermo-rigid-viscoplastic FEM model is selected according to the forming feature of the process, and the variations of the stress-strain fields are studied. Both the influences of the die degree for the deforming and the metal flow and the influencing factors of the deforming force are studied in this paper. The simulation results conform with the test results, which certificate the model. The liquid infiltration-extrusion process is simulated lively by the superiority and powerful nonlinear solution function of the FEM software, the perfect contours and curves are obtained.In this paper, the numerical simulation problem of the liquid infiltration extrusion technology that includes high pressure infiltration, heat conduction, solidification and large deformation is solved successfully, which provides theoretic basis for the parameters optimization and the application of the process.