Practical scheme for predicting twin interface nucleations in single-crystalline Ni-Mn-Ga alloys under coupled magnetic and mechanical loading conditions
Practical scheme for predicting twin interface nucleations in single-crystalline Ni-Mn-Ga alloys under coupled magnetic and mechanical loading conditions
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DOI：
10.1016/j.jmmm.2020.166650
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发表时间：
2020-06
影响因子：
2.7
通讯作者：
Jiong Wang;P. Du
中科院分区：
文献类型：
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作者：
Jiong Wang;P. Du
本文研究了Ni-Mn-Ga单晶样品在磁力耦合作用下的孪晶界面形核现象。首先，提出了一些本构假设，并制定了单晶Ni-Mn-Ga样品的磁-机械控制系统。然后，通过分析一些物理量的连接条件，可以计算任意“虚拟孪晶界面”上的位形力。从控制系统中孪晶界面的运动准则出发，提出了一种在宏观水平上预测孪晶界面形核的实用方案，并将其集成到求解控制系统的迭代数值算法中。为了说明该方案的有效性，一些典型的例子进行了研究。基于数值模拟结果，分析了作用在虚拟孪晶界面上的位形力的演化特性。从而确定了孪晶界面形核的临界载荷状态和优先位置。预测的样品的磁-机械响应与实验结果吻合较好。此外，在不同的加载阶段，样品的配置和样品中的相关物理量的分布可以被模拟。
In this paper, the phenomenon of twin interface nucleations in single-crystalline Ni-Mn-Ga samples under coupled magnetic and mechanical loading conditions is studied. First, some constitutive assumptions are proposed and the magneto-mechanical governing system for a single-crystalline Ni-Mn-Ga sample is formulated. Then, by analyzing the connection conditions of some physical quantities, the configurational forces on any ‘fictitious twin interfaces’ can be calculated. Further from the twin interface movement criteria in the governing system, a practical scheme for predicting twin interface nucleations at the macroscopic level is proposed, which is integrated into an iterative numerical algorithm for solving the governing system. To show the efficiency of this scheme, some typical examples are studied. Based on the numerical simulation results, the evolution properties of the configurational forces on the fictitious twin interfaces are analyzed. Then, the critical loading states and the preferred positions for the nucleations of twin interfaces can be determined. The predicted magneto-mechanical response of the sample can fit the experimental results well. Furthermore, the configurations of the sample and the distributions of the associated physical quantities in the sample during the different loading stages can be simulated.