Numerical Analysis on the Density Uniformity for SiCp/2024Al in the Extrusion Process

Many factors can influence the density uniformity of the SiC particle reinforced aluminum matrix composites, including the material preparation method and the material processing technology. The influence factors on the density uniformity of SiCp/2024Al in the extrusion process were studied in the present investigation. Those factors contain the extrusion ratio, the extrusion velocity, the temperature and the friction coefficient. The flow stress of this material under different temperatures and strain velocities was tested by heat physical simulation experiments. As a result, the true stress-strain curve was obtained and the phenomenological constitutive equation was established, and the FEM simulation was used for the extrusion process. The velocity gradient computed by the numerical simulation was used to describe the density uniformity. The density uniformity caused by different extrusion process parameters was compared and analyzed. The results showed that the density uniformity was improved obviously by the optimization of extrusion process parameters. At last, the real extrusion process test was organized to verify the numerical simulation results and the most suitable characteristic parameters of the extrusion mold and the process was finally determined.