Modeling the non-Schmid crystallographic slip in MAX phases
Modeling the non-Schmid crystallographic slip in MAX phases
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DOI：
10.1016/j.ijplas.2022.103399
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发表时间：
2022-08
影响因子：
9.8
通讯作者：
U. Asim;Zhiqiang Zhan;M. Radovic;A. Srivastava
中科院分区：
文献类型：
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作者：
U. Asim;Zhiqiang Zhan;M. Radovic;A. Srivastava
我们提出了一个晶体塑性本构关系来描述实验观察到的一类通常被称为MAX相的三元碳化物和氮化物的非施密德晶体滑移。在本构关系中，我们假设滑移体系强度在MAX阶段的演化有两个分量——依赖于Taylor累积剪切应变的经典分量和依赖于滑移面法向应力的非施密德分量。利用非schmid晶体塑性本构关系，对Ti2AlC和Ti3AlC2两种MAX相单晶的微柱压缩进行了有限元模拟。有限元模拟不仅定量地预测了微柱在大范围晶体取向下的应力应变响应，而且对两种材料在实验中观察到的微柱的非均匀变形和变形形状进行了合理化。为了量化非施密德效应的作用，了解关键实验参数对两种MAX相微柱应力应变响应的影响，还进行了参数化研究。
We present a crystal plasticity constitutive relation for the description of experimentally observed non-Schmid crystallographic slip in a class of ternary carbides and nitrides commonly referred to as MAX phases. In the constitutive relation, we assume that the evolution of the slip system strength in MAX phases has two components – a classical component that depends on the Taylor cumulative shear strain and a non-Schmid component that depends on the stress normal to the slip plane. The non-Schmid crystal plasticity constitutive relation is then used to carry out finite element simulations of micropillar compression of single crystals of two MAX phases, Ti2AlC and Ti3AlC2. The finite element simulations not only quantitatively predict the stress – strain response of a wide range of crystallographic orientations of the micropillars but also rationalize the non-uniform deformation and the deformed shape of the micropillars observed in the experiments for the two materials. Parametric studies are also carried out to quantify the role of the non-Schmid effect and understand the effects of key experimental parameters on the stress – strain response of the micropillars of the two MAX phases.