电磁场法原位合成WC_p/W丝增强铁基复合材料

In-situ synthesis of WC_p/tungsten wire reinforced iron matrix composite under electromagnetic field

通过对钨丝和灰口铸铁熔体组成的体系施加电磁场,在1573 K时,熔体中的碳原子与钨原子能够原位反应合成碳化钨颗粒。结果表明:当电磁场频率小于4 kHz,得到碳化钨颗粒与钨丝混杂增强灰口铸铁基复合材料;当电磁场频率达到4 kHz时,得到碳化钨颗粒增强灰口铸铁基复合材料。电磁场除了加速熔体中的质量传递外,还有助于在钨丝周围形成一系列的Fe-W-C三元微区,该微区中钨的浓度较高,利于改善原位合成WC颗粒的动力学条件。但是,WC颗粒的间隙类似于一个过滤器,降低了元素的扩散速度。复合材料较好的耐磨性归因于WC颗粒的较高硬度以及颗粒的弥散分布。

Tungsten carbide（WC） particles were in-situ synthesized using tungsten wires and gray cast iron molten at 1573 K under electromagnetic field and WCp /tungsten wire reinforced iron matrix composite was fabricated.The experimental results indicate that the reinforcement formed in the composite depends on frequency of the electromagetic field,when the frequency of electromagnetic field is below 4 kHz,the composite is reinforced by both in-situ synthesized WCp and residual tungsten wires,when the frequency is 4 kHz,tungsten wires are completely reacted and the composite is reinforced by in-situ synthesized WCp.The electromagnetic field accelerates mass transfer process in the molten,contributes to quickly form local Fe-W-C ternary zones with high tungsten content around the tungsten wires and promotes the synthesis of WCp.However,the gaps of the inter-WCp particles play a role of a filter which hinders the diffusion of elements.The composite exhibits high wear resistance due to higher hardness WCp and its dispersive distribution in the matrix.