关键词: 界面反应, 反应区, 反应动力学, 原子扩散

Abstract: The microstructure of the reaction zone and the reaction kinetics of sintered α-SiC/Fe-20Cr alloy
annealed at 900℃ to 1150℃ were studied by using XRD, EMPA, SEM. The reaction zone can be divided into two sections of the SiC
reaction zone and the metal reaction zone, according to the morphology and element distributions of the reaction zone of SiC/Fe-20Cr. The SiC reaction zone has
high Fe and Si, but low Cr concentration, and it is composed of the bright matrix of Fe₃Si, Cr₇C₃ and Cr₃Si, and randomly distributed graphite
precipitates. The metal reaction zone is a uniform region of (Cr,Fe)₇C₃, possessing very high Cr content. It is believed that the interface reaction is
controlled by the atom diffusion through the reaction zone, and the reaction rate constant K is equal to 1.9×10^-4exp((-235×10³)/RT)m²·s^-1. The metal reaction zone hinders the interface reaction
by inhibiting the diffusion of Fe atoms from the alloy towards the SiC reaction zone. The effect of the metal reaction zone can be improved with the increase of
Cr content of the Fe-Cr alloys.

Key words: interface reaction, reaction zone, reaction kinetics, atom diffusion