TiNi形状记忆合金低速冲击响应行为的研究

Study on low velocity impact response behavior of TiNi shape memory alloy

利用单摆冲击试验设备,对TiNi合金不同冲击能量及温度条件下的冲击响应行为进行了研究。冲击过程中的接触载荷由压力传感器及数字信号处理系统实时测量。根据接触载荷数据,可计算得到接触载荷与样品表面变形的关系。结果表明,同一冲击高度时,随温度升高马氏体TiNi合金的最大接触载荷增加,而接触时间降低;母相TiNi合金的最大接触载荷随冲击高度的增加会出现载荷平台段即伪弹变形段,处于平台段时母相TiNi合金吸收冲击能量,且不产生不可恢复的塑性变形,最大接触载荷降低,从而可减轻材料损伤。

The dynamic impact response behaviors of TiNi alloy at various impact energy and temperature were studied using the simple pendulum impact testing system. The contact force during impact process was measured by force sensor and data signal processing system in real time. Based on the achieved contact force data, the relation of the contact force and deformation depth of specimens can be obtained by calculation. The results show that the maximum contact force and contact time of martensitic TiNi alloy increased and decreased respectively with increasing temperature for a fixed impact height. The maximum contact force of parent phase TiNi alloy showed a plateau with increasing impact height, and the TiNi alloy left no permanent deformation but absorbed impact energy during plateau stage. The dynamic impact response behaviors of martensitic TiNi alloy were affected by its reverse martensitic transformation. During pseudoelastic deformation stage, the parent phase TiNi alloy can absorb impact energy, which reduce the maximum contact force and material damage.