摘要
采用DSC、SEM等方法,研究了时效温度对马氏体相变及其逆相变温度、相变滞后、平均相变焓以及微观组织的影响。结果表明:在300～400℃,NiTiNb9合金存在一个敏感时效温度,在这个敏感温度区间处理,其相变温度会发生突变,而在这个敏感温度之前或之后的温度区间,NiTiNb9合金的相组成基本保持不变。微观组织分析表明,NiTiNb9合金在时效过程中析出的一些细小的β-Nb相颗粒,会形成应力场抑制马氏体的形核和长大,从而使得马氏体相变温度降低;与此同时,由于Nb元素的扩散,部分Nb将取代基体相中的Ni位置,引起基体中Ni/Ti原子比的微小变化,从而使马氏体相变温度发生变化。
Based on DSC, SEM, the influences of aging temperature on martensite transformation and its inverse transformation temperature, phase hysteresis, phase change enthalpy and microstructure were investigated. The results show that NiTiNb9 alloy occurs sensitively among some aging treatment temperatures by 300-400℃. When treating the alloy at this sensitive temperature region, the phase transformation temperature will take place great grads, but before or after the sensitive region, the phase composition of NiTiNb9 alloy keeps steady basically. The analysis of microstructure indicates that some particles of 13-Nb phase are precipitated during ageing treatment, which can form stress field to inhibit the formation and increasing of Martensite phase, which reduces martensite transformation temperature further. Meanwhile, part of Nb atoms can replace Ni atoms in matrix phases for the spreading of [3-Nb phase, and then cause subtle change of Ni/Ti atomic ratio in matrix, and Martensite transformation temperature will be altered.
出处
《热加工工艺》
CSCD
北大核心
2013年第12期164-168,共5页
Hot Working Technology
基金
记忆合金管接头应用研究项目支持(KZ26090310)
