Nb-Ni-Ti系低Ni侧1000℃相平衡研究  

Phase Equilibria of the Low-Ni Side in Nb-Ni-Ti System at 1000 °C

作　　者：李志超[1] 李洪晓[1] 任玉平[1] 蒋敏[1] 秦高梧[1] 

机构地区：[1]东北大学材料各向异性与织构教育部重点实验室,辽宁沈阳110819

出　　处：《稀有金属材料与工程》2017年第7期1875-1880,共6页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(50971037);辽宁省高校重点实验室支持计划(LS2010062)

摘　　要：利用SEM、EPMA、XRD、DSC对Nb-Ni-Ti系低Ni侧1000℃的液相相关相平衡进行了研究。结果表明,1000℃时,在Nb-Ni-Ti系低Ni侧存在着一个可与(Nb,bTi)连续固溶体和TiNi化合物相平衡的液相区;该液相区源自Ti-Ni二元系,延伸至Nb含量3.7%(原子分数)。而二元化合物TiNi在1000℃时则可以溶解约8.0%Nb。1000℃时,Nb-Ni-Ti系低Ni侧等温截面相图中存在2个三相区Liquid+(Nb,bTi)+TiNi和(Nb,bTi)+TiNi+XB,XB是成分为34.0Nb-44.9Ni-21.1Ti的六方结构化合物;这2个三相区之间则是宽阔的(Nb,bTi)+TiNi两相区。在该两相区内,连续固溶体(Nb,bTi)中的Ni含量变化不大、约为3%,Ti含量的变化范围为6.6%~39.9%。而3.7%Nb的溶入未能使二元化合物Ti_2Ni相的稳定存在温度提高到1000℃。The phase equilibria related to the liquid phase at 1000 °C in low-Ni side of the Nb-Ni-Ti system were investigated by SEM, EPMA, XRD and DSC. The results show that there is a liquid phase filed which could be in equilibrium with the continuous solid solution（Nb,？Ti） and compound Ti Ni in the low-Ni side of the Nb-Ni-Ti system at 1000 °C. The liquid phase field originates from binary Ti-Ni system and extends to 3.7%Nb（atomic fraction）. The solid solubility of Nb in the compound Ti Ni is about 8.0%. At 1000 °C, there are two three-phase fields including Liquid＋（Nb, ？Ti）＋Ti Ni and（Nb, ？Ti）＋Ti Ni＋XB in the Nb-Ni-Ti system, where XB is a hexagonal compound with the composition of 34.0Nb-44.9Ni-21.1Ti（atomic fraction, %）. A broad two-phase field（Nb, ？Ti）＋Ti Ni exists between the two three-phase fields. In this two-phase field, the Ni content in the continuous solid solution（Nb, ？Ti） is about 3%, but the Ti content varies from 6.6% to 39.9%. The thermo-stability of the compound Ti2 Ni has been improved by the solution of Nb atoms, but the Ti2 Ni with 3.7%Nb could not exist at 1000 °C.

关 键 词：Nb-Ni-Ti系 液相区 固溶度 相平衡 

分 类 号：TG146.416[一般工业技术—材料科学与工程]