等离子加热反应合成TiB_2-TiC-Fe_2Ti复合材料

TiB_2-TiC-Fe_2Ti composite synthesized by plasma heating reaction

以Ti、B4C和Fe粉为原料,采用等离子束加热反应合成TiB2-TiC-Fe2Ti复合材料,分析了其物相、组织结构、显微硬度和断口形貌等。结果表明:反应生成物中物相主要有TiB2、TiC和Fe2Ti,同时含有少量的Fe3C。各物相以不同的形态均匀分布,TiB2呈现六边形和长条形,TiC近似球形,Fe2Ti作为粘结相存在于TiB2和TiC相之间,促进了各相之间的结合。等离子束加热具有高加热及冷却速率,降低了晶粒生长时间,有利于获得细小的组织。随着电流增加,单位时间内输入坯体热量增多,TiB2和TiC充分长大,各相之间结合更加紧密。

TiB2-TiC-Fe2Ti composites were prepared by plasma heating synthesis with Ti,B4 C and Fe powders as the raw materials.The phase constitution,microstructure,micro-hardness and fracture morphology of TiB2-TiCFe2Ti were investigated.The experimental results show that the reaction products are composed of TiB2,TiC,Fe2 Ti and a small amount of Fe3 C.The TiB2,TiC and Fe2 Ti phases distribute homogeneously and present in different shapes,in which TiB2 phases are in hexagonal or rectangular shapes and TiC in spherical ones,while Fe2 Ti phases existing in the gaps between TiC and TiB2 phases promote the combination of phases.As the heating rate and the cooling rate of plasma beam are fast,the time of the grain growth would decrease and the fine structures can be obtained.With the increasing current,the heat will be higher to promote the growing of TiB2 and TiC,which would bond to each other tightly.