热处理对NiTi形状记忆合金的相变的影响

Influence of Heat Treatment on Phase Transformation of NiTi Shape Memory Alloys

摘要: 对含Ti 50.8%的NiTi形状记忆合金在300℃、400℃、500℃保温不同时间进行时效处理,然后通过差示扫描量热仪DSC对其相变温度点进行测定,发现经时效处理调节后,A_f最大可下降20~30℃左右,而M_s变化不大。通过不同时效温度和保温时间的DSC曲线比较,得出热处理对其相变温度点的影响规律,即在300~500℃时效处理时,保温时间越短,A_f降低越明显,在相同保温时间时,保温温度越低,A_f降低越明显。

Abstract: 50.8%Ti-Ni shape memory alloys are heat treated at different temperatures for different times and the temperature of transformation is measured with DSC.The A_f of NiTi shape memory alloys decreased around 20℃ to 30℃and the M_s of the alloys changed little through heat treatment.The influence of heat treatment on the phase transformation of NiTi shape memory alloys is discussed by comparing the DSC curves.It is indicated that when aged at 300℃-500℃,the shorter the holding time,the lower the A_f,in the same time,the lower holding temperature leads lower A_f.