Nb-Ni-Ti系L(βTi,Nb)+TiNi共晶相平衡研究

Phase equilibria of eutectic transformation L(βTi,Nb)+TiNi in Nb-Ni-Ti system

采用合金平衡组织结构分析法结合热分析,研究了Nb-Ni-Ti系L(βTi,Nb)+TiNi共晶相平衡.结果表明,随着温度的降低,处于液相L、(βTi,Nb)和TiNi相三相平衡时的(βTi,Nb)相中Ni含量(摩尔分数)几乎不变,约为3.5%;而Nb的摩尔分数逐渐降低,从1 050℃时的62.6%,降为1 000℃时的54.1%;但TiNi相的成分变化不大.L+(βTi,Nb)+TiNi三相区也随温度的降低逐渐远离Nb-TiNi连线.并且随着Nb的溶入,Ti2Ni相的熔化温度也得以提高.

The phase equilibria related with eutectic transformation L(β Ti,Nb)+TiNi of Nb-Ni-Ti system have been investigated through the equilibrated alloy method and DSC.It has been shown that,the three-phase field L+(β Ti,Nb)+TiNi shifted away from the Nb-TiNi tie-line with the decrease of the temperature;the Ni content(mole fraction)in(β Ti,Nb) was almost the same ~3.5%;but the mole fraction of Nb decreased as temperature dropped,from 62.6% at 1 050 ℃ to 54.1% at 1 000 ℃.The composition of TiNi phase varied little with temperature.The melt temperature of Ti2Ni increased with the solution of Nb atoms.