Muraishi Shinji
Materials Science and Engineering, Tokyo Institute of Technology, Tokyo 152-8552, Japan.
Materials (Basel). 2021 Oct 4;14(19):5811. doi: 10.3390/ma14195811.
The fine misfit precipitates in age-hardenable aluminum alloys have important roles due to their excellent age-hardening ability, by their interaction with dislocations. The present study focused on the internal stress field of plate-shaped misfitting precipitates to evaluate their roles in dislocation overcoming the precipitates by means of micromechanics based on Green's function method. The stress field of misfit precipitates on {001} and {111} habit planes were reproduced by homogeneous misfit strain (eigenstrain) of the precipitate (Eshelby inclusion method), and the dislocation motion vector on the primary slip plane was predicted by the force acted on the dislocation by the Peach-Koehler formula. According to simulation results, the dislocation interaction strongly depends on the stress field and geometry of misfit precipitates; repulsive and attractive forces are operated on the dislocations lying on the primary slip plane when the dislocation approaches the misfit precipitates. The hardening ability of different orientations of precipitation variants was discussed in terms of interaction force acted on the dislocation.
时效硬化铝合金中的细小不匹配析出相因其出色的时效硬化能力以及与位错的相互作用而具有重要作用。本研究聚焦于板状不匹配析出相的内应力场，通过基于格林函数法的微观力学来评估它们在位错克服析出相过程中的作用。通过析出相的均匀错配应变（本征应变）（埃舍尔比夹杂法）再现了{001}和{111}惯习面上不匹配析出相的应力场，并根据皮奇 - 科勒公式由作用在位错上的力预测了主滑移面上的位错运动矢量。根据模拟结果，位错相互作用强烈依赖于不匹配析出相的应力场和几何形状；当位错接近不匹配析出相时，主滑移面上的位错会受到排斥力和吸引力的作用。从作用在位错上的相互作用力角度讨论了不同取向析出变体的硬化能力。
