铜基形状记忆合金异常相变内耗的研究

文章研究了Cu-Al-Ni-Mn-Ti多晶形状记忆合金的异常相变内耗。实验结果和理论分析表明,合金的高温相变内耗峰在测量频率较低、马氏体片较多及升温速度较大的情况下,分解为一个"正峰"和一个"倒峰",这种现象是由于2种正、负耗散弹性模量的马氏体变体间相互作用引起的;具有负弹性模量的形状记忆合金能够稳定存在的条件,是需要从环境吸收热量引起熵的增加。

Study on anomalous internal friction during phase transformation of Cu-based shape memory alloys

The anomalous internal friction during phase transformation in a Cu-Al-Ni-Mn-Ti polycrystalline shape memory alloy is studied in the paper.The experimental results and theoretical analysis show that the high-temperature internal friction peak is evolved into an "ordinary peak" and an "inverted peak" in the alloy in the case of lower frequencies,more martensite plates and higher heating rates,which arise from the interaction between two types of martensitic variants with positive and negative loss elastic modulus.A necessary criterion for the stability of the shape memory alloy with negative loss elastic modulus requires the absorption of heat from surroundings,thus causing an increment of entropy.