In this paper, we probe the bonding mechanisms for an impacting particle on a substrate, as in the cold spray process, over a range of impact velocities using molecular dynamics simulations. For the model copper/copper system, we find that grain boundary-like amorphous phase interlocking and metallurgical bonding are dominant at low and medium impact velocities, respectively, while metallurgical bonding and mechanical interlocking are dominant at high impact velocities. In particular, features including substrate crater depth, particle flattening ratio, and jetting area are tracked with varying impact velocities to further enhance our understanding of the underlying bonding mechanisms and the grain refinement in and around the interface. Because our findings are based only on small particle simulations allowable in MD, size effects can preclude extrapolating the results to physical micron-sized particles used in actual cold spray.

在本文中，我们使用分子动力学模拟在一定范围内的冲击速度内探索了撞击粒子在基底上的键合机制，如在冷喷涂过程中。对于模型铜/铜系统，我们发现晶界状非晶相联锁和冶金结合分别在低冲击速度和中等冲击速度下占主导地位，而冶金结合和机械联锁在高冲击速度下占主导地位。特别是，包括衬底凹坑深度、颗粒扁平率和喷射面积在内的特征会以不同的冲击速度进行跟踪，以进一步增强我们对界面内和周围的潜在键合机制和晶粒细化的理解。因为我们的发现仅基于 MD 允许的小粒子模拟，