摘要
采用差示扫描量热法研究了时效处理对N iTi形状记忆合金加热相变过程的影响规律。结果表明:当时效温度低于T0(特征转折温度)时,相变温度(AS和Af)随时效温度的升高而升高;当时效温度高于T0时,相变温度随时效温度的升高而下降。对于AS,当时效15m in时,T0=500℃,当时效30m in时,T0=400℃;对于Af,T0均为400℃。在300℃、400℃和500℃时效15m in,加热相变过程为M→R和R→P两阶段,在600℃和700℃时效15m in时,加热相变过程为M→P一阶段;当时效时间延长至30m in时,加热相变过程由M→R和R→P两阶段相变过程变为M→P一阶段。时效温度为500℃和700℃时,体积转变率与温度关系曲线的斜率较大。
Effects of ageing on heating transformation of NiTi shape memory alloys were investigated by DSC analysis method. The results show that the transformation temperature As and Af increase as the ageing temperature increasing when the ageing temperature is lower than TO ,while the transformation temperature As and Af decrease as the ageing temperature increasing when the ageing temperature is higher than T0. T0 is related with ageing time：for As, T0 is 500℃ when ageing time is 15min ,and 400℃ with 30min. For Af, TO is always 400℃. Heating transformation of M→R and R→ P occur when the ageing is conducted at 300℃ ,400℃ and 500℃ for 15min ,while the transformation of M→P occurs as the ageing goes at 600℃ and 700℃for 15min. The transformation of M→R and R→P are replaced by M→P as the ageing time increasing to 30min. There is maximum value of df（ P）/dT when ageing at 500℃ and 700℃.
出处
《金属热处理》
EI
CAS
CSCD
北大核心
2005年第10期46-49,共4页
Heat Treatment of Metals
基金
南宁市科技开发计划
