Recovery Behavior of Fe-Based Shape Memory Alloys under Different Restraints
Recovery Behavior of Fe-Based Shape Memory Alloys under Different Restraints
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DOI：
10.3390/app10103441
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发表时间：
2020-05-01
影响因子：
2.7
通讯作者：
Kim, Do-Hyung
中科院分区：
文献类型：
--
作者：
Hong, Ki-Nam;Yeon, Yeong-Mo;Kim, Do-Hyung
本文介绍了铁基形状记忆合金（Fe-SMA）在不同约束条件下的回复行为的评价实验结果。为了研究，生产了三种类型的Fe-SMA（FSMA-A、FSMA-B、FSMA-C）。作为直接拉伸试验的结果，FSMA-A试样的屈服强度比FSMA-B和FSMA-C的强度高近34%。在自由约束条件下，当预应变为0.04，加热温度为200 ℃时，激活后FSMA-A、FSMA-B和FSMA-C试样的恢复应变分别为0.00956、0.01445和0.01977。在刚性约束条件下，当预应变为0.04，加热温度为200 ℃时，激活后FSMA-A、FSMA-B、FSMA-C试样的最终回复应力分别为518、391和401 MPa。在刚性约束条件下，预应变对最终回复应力的影响不明显，而最终回复应力随加热温度的升高而增大。冷却过程中，当Fe-SMA受到约束时，回复应力比刚性约束时低50%。因此，为了形成大的回复应力，在加热期间必须约束Fe-SMA。根据试验结果提出了Fe-SMA管接头有效围压的计算方法。
This paper presents the experimental results of an evaluation of the recovery behavior of Fe-based shape memory alloys (Fe-SMAs) under different restraints. For the study, three types of Fe-SMA (FSMA-A, FSMA-B, FSMA-C) were produced. As a result of the direct tensile test, the yield strength of the FSMA-A specimen was nearly 34% higher than the strength of FSMA-B and FSMA-C. Under free restraint, the recovery strains are 0.00956, 0.01445, and 0.01977 for FSMA-A, FSMA-B and FSMA-C specimens, respectively, after activation when the pre-strain is 0.04, and the heating temperature 200 degrees C. Under rigid restraint, the final recovery stresses are 518, 391 and 401 MPa for FSMA-A, FSMA-B, FSMA-C specimens after activation when a pre-strain of 0.04 and heating temperature 200 degrees C. Additionally, under the rigid restraint, the effect of pre-strain on the final recovery stress was insignificant, whereas the final recovery stress increased as the heating temperature increased. When Fe-SMA was constrained during cooling, the recovery stress is 50% lower than under rigid restraint. Hence, in order to develop a large recovery stress, Fe-SMA must be constrained during heating. In addition, a method for calculating the effective confining stress of the Fe-SMA coupler for pipe joining was proposed based on the experimental results.