Ti对SPS烧结Nb/Nb5Si3复合材料组织和性能的影响

以Nb、Si和Ti粉末为原料,采用放电等离子烧结(SPS)技术对Nb-20Si、Nb-20Si-5Ti、Nb-20Si-15Ti和Nb-20Si-24Ti材料进行原位合成。利用扫描电镜(SEM)、电子探针微区分析(EPMA)和X射线衍射(XRD)等手段对材料的组织结构进行分析,探讨Ti对复合材料组织和性能的影响规律。结果表明,Ti元素的加入使得复合材料中Nb5Si3相转变成(Nb,Ti)5Si3,随着Ti加入量的增加,组织中出现了单质的Ti相,当Ti含量达到24%时,组织中还会出现Nb3Si相;同时Ti的加入会降低复合材料的硬度,提高其高温抗氧化性能。

Effects of Ti Addition on Microstructure and Properties of Nb/Nb5Si3 in situ Composites by Spark Plasma Sintering

The microstructure and properties of Nb/Nb5Si3 in situ composites prepared from Nb-20Si, Nb-20Si-5Ti, Nb-20Si-15Ti and Nb-20Si-24Ti by the spark plasma sintering (SPS) technique. The microstructures of the synthesized composites were analyzed by SEM, XRD and electron probe microscopy (EPMA). The effects of Ti addition on the microstructure and properties of Nb/Nb5Si3 in situ composites were studied. The result show that the main phase of the composites changes from Nb/Nb5Si3 to Nb/(Nb, Ti)5Si3 due to the Ti addition. The pure Ti phase and Nb3Si phase are found in the composites when the Ti content reaches to 24%. With the content of Ti increasing, the hardness of Nb/Nb5Si3 in-situ composites would be decreased, but the high temperature oxidation property would be increased