致密WC增强铁基表面复合材料的原位制备与形成机理

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

利用铸渗复合-热处理工艺制备致密碳化钨增强铁基表面复合材料,研究了不同保温时间下复合材料的物相组成与微观组织.结果表明,不同保温时间下,复合材料表面均有致密碳化钨层生成,反应层厚度最大为148μm.致密碳化钨层的显微硬度随保温时间无明显变化,均明显高于铁基体.铁基表面致密碳化钨的形成主要依赖于Fe-C-W体系中碳和钨原子的扩散与原位反应.

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.