材料的应变率强化与磨削加工中的尺寸效应

根据对磨粒接触区材料应变、应变率的分析，以及剪切区热量分配的简化公式，考虑金属材料的应变率效应对磨削过程的影响，指出磨削中的尺寸效应在一定程度上与材料的应变率强化效应有关，认为尺寸效应是应变硬化、应变率强化所造成的热软化，以及材料缺陷等多种因素共同作用的结果，在某些条件下，应变率效应将起主要作用。磨削速度与未变形切屑厚度的乘积是决策 剪切变形机制的重要参数。该乘积值超过临界值，有可能形成失稳剪切。

Strain Rate Strengtheningof Workpiece Materialand the Size Effect Involved in Grinding

According to the analysis on strain and strain rate of contact zone material for an individual grain , combined with a simplified expression of the percentage coefficient of heat transfer in shear band ,the effect of high strain rate of contact zone material on metal grinding process is investigated . It is proposed that the strain rate effect of the contact zone material has a very important influence on the size effect involved in grinding. The size effect is a combined behavior caused by several mechanisms including the strain rate effect. Under certain conditions , the strain rate effect may play main role.