Zheng Haiwei, Liu Jianbin, Muraishi Shinji
Department of Materials Science and Engineering, Tokyo Institute of Technology, Tokyo 152-8550, Japan.
Midea Group Co., Ltd., Foshan 528311, China.
Materials (Basel). 2024 Oct 18;17(20):5076. doi: 10.3390/ma17205076.
Stress-oriented precipitation and the resulting mechanical anisotropy have been widely studied over the decades. However, the local anisotropy of precipitates with specific orientations has been less thoroughly investigated. This study models the interaction between an edge dislocation source and {100} variants of Guinier-Preston (GP) zones in Al-Cu alloys using the parametric dislocation dynamics (PDD) method. Concentric geometrically necessary dislocation (GND) loops were employed to construct a line integral model for thin platelets. The simulations, conducted with our self-developed code based on Green's function method and Eshelby inclusion theory revealed distinct strengthening behavior along the strong and weak directions for 60° GP zones, demonstrating anisotropic strengthening from the perspective of elastic interactions. Furthermore, the optimal inclined arrangement of the GP zone array was determined through elastic energy calculations, and these results were corroborated by TEM observations.
几十年来，应力诱导析出及由此产生的力学各向异性已得到广泛研究。然而，具有特定取向的析出相的局部各向异性尚未得到充分研究。本研究采用参数化位错动力学（PDD）方法，对铝铜合金中刃型位错源与Guinier-Preston（GP）区{100}变体之间的相互作用进行了建模。采用同心几何必要位错（GND）环构建了薄片的线积分模型。利用我们基于格林函数法和埃舍尔比夹杂理论自行开发的代码进行的模拟显示，60°GP区在强弱方向上表现出明显的强化行为，从弹性相互作用的角度证明了各向异性强化。此外，通过弹性能计算确定了GP区阵列的最佳倾斜排列，TEM观察结果证实了这些结果。
