The role of mechanical loading in bcc-hcp phase transition: tension-compression asymmetry and twin formation
The role of mechanical loading in bcc-hcp phase transition: tension-compression asymmetry and twin formation
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DOI：
10.1016/j.actamat.2022.118377
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发表时间：
2022-09
期刊：
影响因子：
9.4
通讯作者：
Amir Hassan Zahiri;Eduardo Vitral;Jamie Ombogo;M. Lotfpour;Lei Cao
中科院分区：
文献类型：
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作者：
Amir Hassan Zahiri;Eduardo Vitral;Jamie Ombogo;M. Lotfpour;Lei Cao
随着温度或压力的变化，许多体心立方（bcc）材料会发生马氏体bcc-hcp相变，这种相变会产生富含孪晶的马氏体组织。机械载荷也已知对马氏体相变具有巨大影响。在这项工作中，我们将原子模拟与理论计算相结合，研究机械载荷对马氏体微观结构的影响。变形梯度和相变应变的计算表明，{10 1 <$1}相变孪晶和{10 1 <$2}相变孪晶在相反的加载方向上更容易产生。此外，体心立方相中的初始{112}孪晶在相变之后转变为{11 2 <$2}和{11 2 <$1}孪晶。结果揭示了机械加载在特定相变孪晶形成中的关键作用，这可以提供一种新的策略，使用设计的热机械加工工程孪晶微结构。
In response to temperature or pressure changes, many body-centered cubic (bcc) materials undergo martensitic bcc-hcp phase transformation, which is known to produce rich martensite microstructure with internal twins. Mechanical loading is also known to have a huge impact on martensitic phase transformation. In this work, we integrate atomistic simulations with theoretical calculations to investigate the effect of mechanical loading on the martensite microstructure. The calculations of deformation gradients and transformation strains reveal that the {10 1¯ 1} transformation twins and {10 1¯ 2} transformation twins are favored by opposite loading directions. Furthermore, the initial {112} twin in the bcc phase is transformed into {11 2¯ 2} and {11 2¯ 1} twins after the phase transformation. The results reveal the critical role of mechanical loading in the formation of the specific transformation twinning, which could offer a novel strategy to engineer twin microstructure using designed thermomechanical processing.