Fabrication of SiC/Al Functionally Graded Materials Via Filtration Extrusion

Abstract

Functionally graded materials (FGMs) have broad application prospects owing to their outstanding material properties. Herein, a filtration extrusion device is designed, and low‐content SiC/Al composites are used to explore the feasibility of applying filtration extrusion techniques to the fabrication of FGMs. The results suggest that the extrusion force increases monotonically with an increase in the filtration extrusion ratio. Furthermore, the filtration extrusion process can be divided into two stages based on the change trend of extrusion pressure: at stage 1, extrusion force is small and increases slowly. At stage 2, the extrusion force increases significantly and rapidly. During the filtration extrusion process, the larger the initial content, the lower the extrusion temperature, the smaller the hole‐separation mold area ratio, the faster the increase in the extrusion force, and the greater the maximum extrusion force during the extrusion process. Based on filtration extrusion experiments for various extrusion distances, it is found that the transition from the nonflow to the flow influence zone is primarily responsible for the enrichment and gradient distribution of SiC particles. The SiC particles are distributed in a gradient, and the content of SiC particles near the separation mold is higher than that on the other side.