In situ SR-CT experiment of Al–SiC microwave rapid sintering: Formation and regulation of rapid densification

Abstract

SiC reinforced Al (SiC/Al) composites have outstanding advantages in different fields including aerospace. However, the current mechanical and chemical properties of Al–SiC composites are still not up to expectations because of the problems such as wettability, interface reaction, sintering time and SiC size and distribution. Microwave rapid sintering has a promising prospect for the preparation of high performance Al–SiC, however, the lack of process observation leads to the unclear relationship of energy, microstructure and material properties. Therefore microwave rapid sintering of Al–SiC has not been fully explored and applied. In the present paper, the whole process of Al–SiC microstructure evolution was observed accurately by in situ SR-CT experiment during microwave rapid sintering process. Based on the joint analysis of energy-structure-performance, it was found that the spherical SiC located at the neck of Al particles in the microwave field effectively increased the diffusion rate of Al–SiC samples, which inhibited the growth of grains and the densification process was basically completed in a short time. It was revealed that a region with high electric field strength and uniform distribution formed due to SiC with different structural characteristics, thus achieved the rapid densification of the Al–SiC in microwave sintering. The formation and regulation mechanism of rapid densification of Al–SiC during microwave rapid sintering were researched by the relationship between energy-structure and performance, which would provid more understanding for the preparation of high-performance Al–SiC based on microwave rapid sintering technology, and provide the possibility for the preparation of more functional materials.