The present study investigates the high-temperature shape memory effect (SME) in heterophase Ni_50.3Ti_32.2Hf_17.5 polycrystals with nanosized H-phase particles after stress-induced martensite (SIM) aging in tension and compression. SIM aging created the conditions for fully reversible two-way SME with a strain of up to 50% of the one-way shape memory strain. SIM aging altered the viscoelastic properties of material, in particular, the elastic moduli of austenite and martensite increased, as did internal friction. Increased interface mobility is suggested as the reason for internal friction growth.

中文翻译：

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Ni _50.3 Ti _32.2 Hf _17.5高温形状记忆合金中应力诱导的马氏体时效拉伸和压缩对B2-B19'马氏体相变的影响

本研究研究了应力诱发马氏体（SIM）在拉伸和压缩状态下老化后，具有纳米级H相颗粒的Ni _50.3 Ti _32.2 Hf _17.5多相Ni _50.3多晶的高温形状记忆效应（SME）。SIM老化为完全可逆的双向SME创造了条件，其应变高达单向形状记忆应变的50％。SIM时效改变了材料的粘弹性，特别是，奥氏体和马氏体的弹性模量增加了，内部摩擦也增加了。建议增加界面的流动性作为内部摩擦力增加的原因。