Study on Microstructure of Fe-VC Surface Composites Synthesized by Cast-sintering Technique
Using the metal powder mixture containing V, Cr, C, Fe, Ni elements as raw material, Fe-based composites reinforced with VC particles was obtained on the surface of the castings by cast-sintering technique. The microstructure of the composites was analyzed by SEM, XRD. The mechanism of VC produced by in-situ synthesis was studied by thermodynamics principles. The results show that the reactions occurred in the compound material layer include the decomposition of ferrovanadium powder, the in-situ generating of reinforcing particles and the densification of microstructure during cast-sintering process. The reinforcing particles which are with regular shape and uniform distribution have a good bonding with the matrix; Metallurgical bonding can be obtained between the compound material layer and the matrix, and accompanied with diffusion; The thermodynamic calculation results on the in-situ reaction show that the possible reaction products produced by in-situ synthesis at 1 773 K are V8C7, which are consistent with the XRD result.