The fundamental evolution mechanisms of many important phenomena accompanying explosive welding of metal foils remain a subject of open discussion, due to the extreme difficulties of in-situ observations. In this work, a comprehensive study combined SPH (smoothed particles hydrodynamics) simulation and advanced characterization was performed to investigate the interfacial evolutions, nano-mechanical properties, and the associated governing mechanisms in Cu foil/Fe welding system. Based on the simulation results, a detailed evolution model of the wave formation was given, and a new explanation for the vortex formation was proposed. The microstructure analyses revealed that the grain structures adjacent to the joining interface were dramatically changed, where two different morphologies of equiaxed and columnar grains were detected at Fe and Cu side, respectively, and the vortex area was built of ultra-fine equiaxed nanometer grains. These microstructure changes were correlated very well with the nano-mechanical properties, and the perplexing evolution processes can be explained by dynamic recovery and recrystallization accompanied by different degrees of crystal growth and deformation. The predicted widths of recrystallization layer and hardened layer agree well with the experimental results, suggesting that the SPH simulation allows predicting the microstructure evolution during the high speed impact welding process in a quantitative way.

由于现场观察的极端困难，伴随金属箔爆炸焊接而发生的许多重要现象的基本演变机理仍然是公开讨论的主题。在这项工作中，进行了结合SPH（光滑颗粒流体动力学）模拟和高级表征的综合研究，以研究Cu箔/ Fe焊接系统中的界面演变，纳米机械性能以及相关的控制机制。在仿真结果的基础上，给出了详细的波形成演化模型，并提出了涡旋形成的新解释。显微组织分析表明，连接界面附近的晶粒结构发生了巨大变化，在Fe和Cu侧检测到两种等轴和柱状晶粒的形态，旋涡区域分别由超细等轴纳米晶粒构成。这些微观结构的变化与纳米机械性能具有很好的相关性，并且复杂的演化过程可以用动态恢复和再结晶以及不同程度的晶体生长和变形来解释。预测的再结晶层和硬化层的宽度与实验结果吻合得很好，这表明SPH模拟可以定量地预测高速冲击焊接过程中的组织演变。复杂的演化过程可以通过动态恢复和再结晶以及不同程度的晶体生长和变形来解释。预测的再结晶层和硬化层的宽度与实验结果吻合得很好，这表明SPH模拟可以定量地预测高速冲击焊接过程中的组织演变。复杂的演化过程可以通过动态恢复和再结晶以及不同程度的晶体生长和变形来解释。预测的再结晶层和硬化层的宽度与实验结果吻合得很好，这表明SPH模拟可以定量地预测高速冲击焊接过程中的组织演变。