W和W-Mo对等离子烧结Nb/Nb5Si3复合材料显微组织的影响

Effects of W and W-Mo Additions on Microstructures of Nb/Nb5Si3 in Situ Composites by Spark Plasma Sintering

摘要:

利用等离子烧结（SPS）技术，对Nb-20Si，Nb-20Si-10W和Nb-20Si-10W-10Mo试样进行了烧结，主要研究了W和W-Mo对Nb/Nb5Si3复合材料显微组织的影响。利用扫描电镜（SEM）观察显微组织，X射线衍射仪（XRD）分析相组成，电子探针微观分析（EPMA）进行成分分析。结果表明：烧结样品相对密度达到99.59%；W可以很好地固溶在Nb/Nb5Si3复合材料中，且显微组织没有变化；W-Mo固溶后显微组织有明显变化，出现了单质Nb相，W和Mo复合固溶的Nb相固溶体，并且有部分Nb固

Abstract:

Nb-20Si, Nb-20Si-10W and Nb-20Si-10W-10Mo samples were prepared by a spark plasma sintering (SPS), the effects of W and W-Mo additions on the microstructure of Nb/Nb5Si3 composites were mainly investigated. The microstructures were examined by scanning electron microscope (SEM). X-ray diffraction (XRD) was used for phase identification of the samples. The compositions were analyzed by electron-probe micro-analysis (EPMA). Results indicate that Nb/Nb5Si3 composites up to 99.59% of theoretical density are fabricated. W can be perfect solid-solutioned in Nb/Nb5Si3 composites, and the microstructure of Nb/Nb5Si3 composites is not changed, but the microstructure of Nb/Nb5Si3 composites is obviously changed after addition of W-Mo, Nb monophase, the solid solution of W and Mo in Nb, and the solid solution of partial Nb in W appear, but the solid solution phenomena of Nb5Si3 is not detected.