Abstract Laser surface re-melted Al–Al2Cu eutectic alloy with α-Al and θ-Al2Cu nanoscale lamellae exhibits high strength and good plasticity at room temperature, implying that the nanoscale θ-Al2Cu lamellae plastically co-deform with α-Al. Microscopy characterization reveal that plastic deformation of θ-Al2Cu lamellae is accommodated by localized shear on unusual slip planes of {121}Al2Cu. Herein, we elucidate interface-mediated deformation mechanisms of nanoscale Al–Al2Cu eutectics and investigate the structure and properties of the {001}Al‖{001}Al2Cu interface using atomistic simulations. Simulation results reveal that the interface is composed of two sets of misfit dislocations with the displacement shift complete vectors as Burgers vectors. We then conduct simple shear simulations to explore shear response and corresponding mechanisms of the Al–Al2Cu interface, and reveal that interfacial shear is accomplished through the gliding of misfit dislocations on the interface. Plasticity of nanoscale θ-Al2Cu lamellae is examined to be associated with localized shears on {121}Al2Cu planes, which are ascribed to the continuity of slip systems across Al–Al2Cu interfaces and accumulated lattice dislocations at interfaces.

中文翻译：

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纳米级Al-Al2Cu共晶的界面介导塑性

摘要 激光表面重熔 Al-Al2Cu 共晶合金与 α-Al 和 θ-Al2Cu 纳米片层在室温下表现出高强度和良好的塑性，表明纳米级 θ-Al2Cu 片层与 α-Al 发生塑性共变形。显微表征表明 θ-Al2Cu 薄片的塑性变形是由 {121}Al2Cu 的异常滑移平面上的局部剪切调节的。在此，我们阐明了纳米级 Al-Al2Cu 共晶的界面介导变形机制，并使用原子模拟研究了 {001}Al‖{001}Al2Cu 界面的结构和性质。仿真结果表明，界面由两组错配位错组成，位移位移完全向量为伯格斯向量。然后我们进行简单的剪切模拟来探索 Al-Al2Cu 界面的剪切响应和相应机制，并揭示界面剪切是通过界面上错配位错的滑动来实现的。纳米级 θ-Al2Cu 薄片的可塑性经检验与 {121}Al2Cu 平面上的局部剪切有关，这归因于跨越 Al-Al2Cu 界面的滑移系统的连续性和界面处累积的晶格位错。