Abstract Surface integrity is the permanent pursuit of industries for decades, and microstructure is a key factor controlling physical and mechanical properties of machined surfaces. During machining, a complicated non-uniform distribution of deformation fields will be applied to machined surfaces, as a result, microstructure evolution will be significantly influenced. In this study, a coupled finite element (FE) and cellular automata (CA) approach is used to characterize and predict microstructure evolution during high-speed machining oxygen-free high-conductivity (OFHC) copper, where a unique material model is presented to describe both constitutive behaviors and microstructure evolution, and a mixed mechanism of continuous dynamic recrystallization (cDRX) and discontinuous dynamic recrystallization (dDRX) is adopted to show grain refinement and grain growth procedure under gradient distributed fields of strains, strain rates and temperatures in machined surfaces. A similar gradient distribution of grain sizes is obtained through both simulation and experimental results, which validates the predictive model and presents an in-depth understanding of microstructure evolution process during surface formation, and it shows the primary factors influencing the grain size distribution in sub-surface are cDRX-induced grain refinement and dDRX-induced grain growth. Moreover, the gradient distribution of microstructures in refined sub-surfaces could be used to explain mechanisms of sub-surface damage in the future.

中文翻译：

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通过耦合FE和CA方法预测由高速加工引起的加工表面的微观结构梯度分布

摘要 表面完整性是工业界几十年来的永恒追求，而微观结构是控制加工表面物理机械性能的关键因素。在加工过程中，加工表面会产生复杂的不均匀分布的变形场，从而显着影响微观结构的演变。在这项研究中，耦合有限元 (FE) 和元胞自动机 (CA) 方法用于表征和预测高速加工无氧高电导 (OFHC) 铜期间的微观结构演变，其中提出了独特的材料模型以描述本构行为和微观结构演化，采用连续动态再结晶（cDRX）和不连续动态再结晶（dDRX）的混合机制来显示加工表面应变、应变速率和温度梯度分布场下的晶粒细化和晶粒生长过程。通过模拟和实验结果得到了相似的晶粒尺寸梯度分布，验证了预测模型，深入了解了表面形成过程中的微观结构演化过程，揭示了影响亚层晶粒尺寸分布的主要因素。表面是 cDRX 诱导的晶粒细化和 dDRX 诱导的晶粒生长。此外，精细亚表面微结构的梯度分布可用于解释未来亚表面损伤的机制。