Investigation of the martensite variant reorientation of the single crystal Ni-Mn-Ga alloy via training processes and a modification with a silicone rubber
Investigation of the martensite variant reorientation of the single crystal Ni-Mn-Ga alloy via training processes and a modification with a silicone rubber
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DOI：
10.1016/j.matchemphys.2023.127390
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发表时间：
2023-01-23
影响因子：
4.6
通讯作者：
Hosoda, Hideki
中科院分区：
文献类型：
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作者：
Chiu, Wan-Ting;Goto, Akihito;Hosoda, Hideki
Ni-Mn-Ga合金的形状变化可以通过控制温度、应力和/或磁场来驱动，被认为是机器人和智能医疗设备等未来技术应用的有前途的材料。单晶 (SC) Ni49Mn30Ga21 (at.%) 合金具有 7 调制 (7M) 马氏体相，采用浮区 (FZ) 技术制备。对 SC Ni-Mn-Ga 合金进行了基础热分析、物相识别、晶体取向测定、磁性能、力学性能和微观结构观察。在通过引入某些压缩应力循环进行训练过程之前，在磁化强度-磁场 (M-H) 曲线中没有观察到马氏体变体重新取向 (MVR)。在训练过程中，明显发现MVR开始时的压力逐渐减轻。经过一些特定的训练程序后，实现了明显的 MVR。这可能归因于 SC Ni-Mn-Ga 合金孪晶边界处的钉扎效应较小。此外，向SC Ni-Mn-Ga合金引入外部磁场后，出现了明显的形状变化。进一步发现，通过将 SC Ni-Mn-Ga 合金与硅橡胶集成，可以限制所施加的 MVR。
The shape changes of the Ni-Mn-Ga alloys, which could be driven via a manipulation of temperature, stress, and/ or magnetic-field, are considered as promising materials for the application of future technologies, such as robots and smart medical devices. The single crystal (SC) Ni49Mn30Ga21 (at.%) alloy, which possessed a 7-modulated (7M) martensite phase, was prepared by a floating-zone (FZ) technique. The fundamental thermal analysis, phase identification, crystallographic orientation determination, magnetic properties, mechanical properties, and microstructure observations were carried out for the evaluations of the SC Ni-Mn-Ga alloy. Prior to the training processes via an introduction of certain compressive stress cycles, no martensite variant reorientation (MVR) could be observed in the magnetization-magnetic field (M-H) curves. During the training processes, it was obviously found that the stress for the commencement of the MVR was reduced gradually. An apparent MVR was thereafter realized after some specific training procedures. This could be attributed to the less pinning effect at the twin boundaries of the SC Ni-Mn-Ga alloy. In addition, obvious shape changes were revealed after the introduction of an external magnetic field to the SC Ni-Mn-Ga alloy. It was further found that the imposed MVR could be constrained by integrating the SC Ni-Mn-Ga alloy with a silicone rubber.