Featured with various excellent mechanical properties, the high strength Al-Zn-Mg-Cu alloys (7xxx series) have become one of the most widely-used metal materials. During the hot processing of 7xxx alloys, the high stacking fault energy and alloying element concentration can lead to the simultaneous occurrence of several physical mechanisms including the dynamic recovery (DRV), dynamic recrystallization (DRX), dynamic precipitation (DPN), and their interactions. Such complex microstructural mechanisms are difficult to be characterized and modeled in both of the experimental and theoretical aspects. In present work, aiming at 7055 alloy subjected to uniaxial hot compression, the systematic experiment investigation is first conducted to reveal hot deformation behaviors. Based on experimental analysis, a unified crystal plastic (CP) model, incorporating the DRX and DPN, is proposed by combining the viscoplastic self-consistent (VPSC) framework. In the unified model, the DRX and DPN behaviors are described by a physical based continuous dynamic recrystallization (CDRX) model and the classical Kampmann-Wagner numerical (KWN) model, respectively, and the effect of DPN on CDRX is specially modeled. After identifying the model parameters, the unified model can reasonably capture the essential features of DPN, DRX, and mechanical response under different deformation temperatures. Therefore, this study offers an innovative modeling approach for the dynamic evolution of several physical processes, facilitating the further understanding for the hot deformation behaviors of aluminum alloys.

中文翻译：

---

Al-Zn-Mg-Cu 合金热变形过程中的动态析出和再结晶行为：实验和建模


高强度Al-Zn-Mg-Cu合金（7xxx系列）具有各种优异的力学性能，已成为应用最广泛的金属材料之一。在7xxx合金的热加工过程中，高堆垛层错能和合金元素浓度会导致动态回复（DRV）、动态再结晶（DRX）、动态析出（DPN）等多种物理机制同时发生，及其相互作用。这种复杂的微观结构机制很难在实验和理论方面进行表征和建模。在本工作中，首先针对单轴热压缩的7055合金进行了系统的实验研究，以揭示热变形行为。基于实验分析，结合粘塑性自洽（VPSC）框架，提出了融合DRX和DPN的统一晶体塑性（CP）模型。在统一模型中，DRX和DPN行为分别通过基于物理的连续动态再结晶（CDRX）模型和经典Kampmann-Wagner数值（KWN）模型来描述，并且专门建模了DPN对CDRX的影响。确定模型参数后，统一模型可以合理捕捉不同变形温度下DPN、DRX和力学响应的本质特征。因此，这项研究为几种物理过程的动态演化提供了一种创新的建模方法，有助于进一步了解铝合金的热变形行为。