Segal Vladimir
Engineered Performance Materials, 2874 Laurel Ridge Ln, Howell, MI 48843, USA.
Materials (Basel). 2018 Jul 10;11(7):1175. doi: 10.3390/ma11071175.
In this review, severe plastic deformation (SPD) is considered as a materials processing technology. The deformation mode is the principal characteristic differentiating SPD techniques from common forming operations. For large plastic strains, deformation mode depends on the distribution of strain rates between continuum slip lines and can be varied from pure shear to simple shear. A scalar, invariant, and dimensionless coefficient of deformation mode is introduced as a normalized speed of rigid rotation. On this basis, simple shear provides the optimal mode for structure modification and grain refinement, whereas pure shear is “ideal” for forming operations. Special experiments and SPD practice confirm this conclusion. Various techniques of SPD are classified and described in accordance with simple shear realization or approximation. It is shown that correct analyses of the processing mechanics and technological parameters are essential for the comparison of SPD techniques and the development of effective industrial technologies.
在本综述中，严重塑性变形（SPD）被视为一种材料加工技术。变形模式是区分SPD技术与普通成型操作的主要特征。对于大塑性应变，变形模式取决于连续滑移线之间的应变速率分布，并且可以从纯剪切变化到简单剪切。引入了一个标量、不变且无量纲的变形模式系数作为刚体旋转的归一化速度。在此基础上，简单剪切为结构改性和晶粒细化提供了最佳模式，而纯剪切对于成型操作是“理想的”。特殊实验和SPD实践证实了这一结论。根据简单剪切的实现或近似情况对各种SPD技术进行了分类和描述。结果表明，对加工力学和工艺参数进行正确分析对于比较SPD技术和开发有效的工业技术至关重要。
