【摘要】 以Nb,Si粉为原料,采用放电等离子烧结(SPS)技术,原位合成了近理论密度的Nb/Nb5Si3复合材料。利用扫描电镜(SEM)、电子探针微区分析(EPMA)和X射线衍射(XRD)分析了材料的组织结构;通过对SPS过程中不同阶段试样的液淬分析,探讨了复合材料的结构形成机理。结果表明,制备的复合材料由Nb和原位合成的Nb5Si3两相组成,Nb以颗粒状均匀分布在Nb5Si3基体上;Nb5Si3是在Nb,Si颗粒的界面开始反应合成的,随着SPS过程的进行,界面反应不断发生,直至反应物中的Si粉完全转变为Nb5Si3。更多还原

【Abstract】 Taking Nb and Si elemental powders as raw materials,dense Nb/Nb5Si3 composites were successfully fabricated by a spark plasma sintering(SPS)technology.The microstructural features of the synthesized composites were analyzed by OM,SEM,XRD and EPMA.The formation mechanism of the composites was also investigated by a quenching test.The results show that the prepared composites consist of Nb and Nb5Si3 phases,and Nb particles uniformly distribute in the in-situ synthesized Nb5Si3 matrix.During the SPS process,an interfacial reaction occurs between Nb and Si particles to synthesize Nb5Si3 until reactant silicon has been completely reacted.更多还原