An abnormal two-way shape memory effect in a rapidly solidified Ni51Ti49 alloy induced by low temperature constrained aging

作者：Li, Y. Y.; Yao, X. Y.; Cao, S.; Ma, X.; Zeng, C. Y.; Zhang, X. P.^*

来源：Scripta Materialia, 2018, 149: 117-120.

DOI：10.1016/j.scriptamat.2018.02.016

• NiTi alloy
• Two-way shape memory effect
• Constrained aging
• Stress field
• Ni4Ti3 precipitate

An abnormal two-way shape memory effect (TWSME) is found in a rapidly solidified Ni51Ti49 alloy strip undergoing constrained aging treatment at relatively low temperatures (e.g., approximately below 385 degrees C for aging time of 1 h), which embodies the bending of the strip toward constrained position during martensitic transformation on cooling, showing stark difference from normal TWSME. The abnormal TWSME of the alloy is caused by weaker coherent stress field produced by ultrafine nano-sized Ni4Ti3 precipitates than the residual stress field, whereas the latter dominates martensitic transformation and leads to bending with the direction opposite to that of normal TWSME.

• 出版日期2018-5
• 单位华南理工大学