多晶镍钛形状记忆合金相变伪弹性特性的研究

利用四光束云纹干涉法对多晶镍钛形状记忆合金拉伸过程中的马氏体与奥氏体相互相转变以及相界面传播的现象进行了研究.从云纹图可看到,形状记忆合金发生相变时,奥氏体与马氏体的分布以及两相的界面附近的位移场分布.利用材料试验机(MTS Sintech 10/D)获得多晶镍钛形状记忆合金的应力-应变特性;通过云纹图能够发现多晶镍钛形状记忆合金拉伸过程中马氏体的发生、生长和传播规律.结果表明,云纹干涉法可以用来研究形状记忆合金的相变,且结果直观、可靠。

Study on Superelastic Characteristic of Polycrystal NiTi Shape Memory Alloys

The mutual transformation of martensite and austensite and propagation of their interface are studied with four-beam moire interferometry during the process of uniaxial tension of polycrystal NiTi shape memory alloys(SMA). The distribution of Austensite and Martensite as well as the displacement distribution nearby the interface is observed from the moire photograph when the SMA is transformed. The stress-strain characteristic of polycrystal NiTi SMA is got by the materials testing system (Sintech 10/D).The generation,nucleation and propagation of transformation band of NiTi polycrystal can be found from the moire photograph. It makes known that the moire interferometry may be used to study the transformation of SMA and the results are perceived directly and reliable.