In-situ preparation and formation mechanism of dense WC reinforced iron-based composite layer

Densetungsten carbide reinforced iron-based surface layer were prepared via casting-infiltration and heat treatment process. The microstructure of samples obtained by different heating time was researched.The results showed that dense tungsten carbide layer was generated on the surface.The thickness of the layer was increased with the heating time; the maximum thickness reached 148 μm. The micro-hardness of the layer was significantly higher thanthe iron matrix and it didn't change a lot with the varying heating time.The formation of dense tungsten carbide layer depended on the diffusion and the interaction in-situ of C and W atoms in the Fe-C-W system.