Experimental investigations of large strain deformation processes such as cutting and sliding have primarily involved analysis of process-level variables such as deformation forces and surface finish. Using high speed in situ imaging coupled with finite element simulations, we show that these processes exhibit a rich variety of complex plastic flows. Detailed investigations of one such flow mode, termed sinuous flow and widely prevalent in ductile metals, are presented. Sinuous flow involves unsteady local deformation in the form of repeated material folding arising from grain-level heterogeneity. The microstructural basis of this flow, along with quantitative replication of its kinematics, is demonstrated using finite element simulations. Sinuous flow is ubiquitous in that it occurs in different deformation configurations and in other ductile material systems, like some polymers, which are devoid of any grain-structure. Being associated with a range of deleterious effects, methods for disrupting sinuous flow using surface coatings and kinematic constraints are demonstrated. Implications for our general understanding of machining processes are discussed.

对切​​削和滑动等大应变变形过程的实验研究主要涉及对变形力和表面光洁度等过程级变量的分析。使用高速原位成像结合有限元模拟，我们表明这些过程表现出丰富多样的复杂塑性流动。介绍了一种此类流动模式的详细研究，称为正弦流动并在延性金属中广泛流行。蜿蜒流涉及不稳定的局部变形，这种变形以由晶粒级非均质性引起的重复材料折叠的形式出现。这种流动的微观结构基础及其运动学的定量复制，通过有限元模拟得到了证明。正弦流动无处不在，因为它发生在不同的变形配置和其他延展性材料系统中，如某些聚合物，它们没有任何颗粒结构。与一系列有害影响有关，演示了使用表面涂层和运动学约束破坏正弦流动的方法。讨论了对我们对加工过程的一般理解的影响。