论文标题
单轴冲击或坡道压缩的滑动诱导旋转的运动学
Kinematics of slip-induced rotation for uniaxial shock or ramp compression
论文作者
论文摘要
当金属样品塑性变形时，其潜在的晶体结构通常必须旋转才能符合其宏观边界条件。动态压缩群落在利用X射线衍射测量的晶格旋转测量中的兴趣越来越大，以推断哪些可塑性机制的组合在单轴上休克或坡道压缩的晶体中可操作，从而以最大的极端压力和应变速率为材料科学提供了信息。但是，并非广泛理解的是，将旋转与滑移活动联系起来的几种现有模型从根本上不适用于平面压缩方案。我们提出了具有真正的单轴菌株的单晶的分子动力学模拟，并表明传统材料科学中使用的Schmid和Taylor分析无法预测随之而来的晶格旋转。我们提出了一个基于弹性塑料分解的简单替代框架，该框架成功地恢复了这些单晶的观察到的旋转，并可以进一步用于识别手术滑移系统以及在理想的单层和双层滑移情况下对它们的活动量。
When a metallic specimen is plastically deformed, its underlying crystal structure must often rotate in order to comply with its macroscopic boundary conditions. There is growing interest within the dynamic compression community in exploiting x-ray diffraction measurements of lattice rotation to infer which combinations of plasticity mechanisms are operative in uniaxially shock- or ramp-compressed crystals, thus informing materials science at the greatest extremes of pressure and strain rate. However, it is not widely appreciated that several of the existing models linking rotation to slip activity are fundamentally inapplicable to a planar compression scenario. We present molecular dynamics simulations of single crystals suffering true uniaxial strain, and show that the Schmid and Taylor analyses used in traditional materials science fail to predict the ensuing lattice rotation. We propose a simple alternative framework based on the elastoplastic decomposition that successfully recovers the observed rotation for these single crystals, and can further be used to identify the operative slip systems and the amount of activity upon them in the idealized cases of single and double slip.
