Infiltration behavior of copper melt into porous graphite and saturation improvement by WC particles doping

In graphite/copper composites, the intrinsic non-wettability of graphite and copper makes it difficult for the copper melt to realize effective infiltration into the porous graphite matrix. The resulted void defects have reduced the final performance of the composites. It is of great significance to improve the saturation of copper melt in the graphite skeleton, which requires a well understanding of the infiltration behavior of copper melt. In this paper, a two-phase flow finite element model was developed, and verified by previous published experimental data. Effects of the external pressure on the infiltration behavior has been studied, and then an optimization method based on WC particle doping was proposed. Results indicated that effective transfer of displacement pressure at the liquid flow front can reduce the void defects of composite materials. WC doping has reduced the capillary resistance, and effectively improved the copper saturation in the infiltration process from 80.4% to 90.7%. This work provided a new method to reduce the void defects of composites, which may be helpful for the development of high performance copper/graphite composites.