外加电磁场对原位合成WC机制的影响

Effect of Extra-Electromagnetic Field on the Mechanism of In-Situ Synthesis WC

以钨丝和灰口铸铁为原位反应的合成源,研究了在Fe-W-C三元体系中,有无电磁场作用对原位合成WC颗粒的影响,其结果表明:施加电磁场后,不但形成的WC颗粒数量增多,且颗粒的分散性增强,均呈现出反应、过渡、未反应的残余钨丝及基体四个区。未施加电磁场体系中,不但形成的颗粒少、分散性差,而且不存在过渡区。故电磁场的搅拌在半固态中的作用:利于形成一个区域更大的、富钨富碳的Fe-W-C的三元体系微区;确保了扩散通道的通畅,使扩散可持续进行;增强了微区的浓度起伏,这些因素均促进了WC颗粒的合成。

Applying tungsten wire and gray cast iron as reactive sources, this paper studies the effect of electromagnetic field on the in-situ synthesized WC in the Fe-W-C system. The results showed that, a larger number of WC particles were produced with uniformed dispersion after applying electromagnetic field.The obtained micro-structure includes reaction, transition, un-reactive tungsten wire and matrix zones. The number of WC particles is less by applying no electromagnetic field with less particle dispersion transition zone. The stirring functions of electromagnetic field under the semi-solid state：beneficial to form a more wider and rich tungsten and rich carbon Fe-W-C ternary micro-zone;ensuring the smooth flow freely of the diffusion channel and a sustainable development;enhancing concentration fluctuations in the micro region. These factors modifies the formation of WC particles.