Nano-Twinned (NT) Cu under shock loading parallel to twin planes was investigated via nonequilibrium molecular dynamics (NEMD) simulations, with particular attention to the shock response and intrinsic deformation mechanism. During the shock compression process, a novel multi-stage phase transformation (MPT) scenario, i.e., from FCC phase to BCC phase and then to HCP phase, happens due to shock-enhanced twin boundary (TB) sliding. Both increasing the compressive strain caused by shock and decreasing the twin lamellae in the NT Cu can promote the MPT, with which the yield strength retains but the spallation strength increases. The critical shock pressure triggering the MPT depends exponentially on lamellae twin thickness (T). These new results have great potentials for improving the impact resistance of metals by tailoring their internal nanostructures.

通过非平衡分子动力学 (NEMD) 模拟研究了平行于孪晶面的冲击载荷下的纳米孪晶 (NT) Cu，特别注意冲击响应和固有变形机制。在冲击压缩过程中，由于冲击增强孪晶边界 (TB) 滑动，发生了一种新的多阶段相变 (MPT) 情景，即从 FCC 阶段到 BCC 阶段，然后到 HCP 阶段。增加冲击引起的压缩应变和减少 NT Cu 中的孪晶层都可以促进 MPT，从而保持屈服强度但增加散裂强度。触发 MPT 的临界冲击压力以指数方式取决于薄片孪晶厚度 ( T）。这些新结果在通过调整金属内部纳米结构来提高金属的抗冲击性方面具有巨大的潜力。