Abnormal grain growth (AGG) in a Zn-0.8Ag (wt%) alloy, produced through the application of high-pressure torsion (HPT), was systematically investigated using scanning electron microscopy (SEM), electron backscattered diffraction (EBSD), high-resolution transmission electron microscopy (HR-TEM) and microhardness testing. The HPT-deformed alloy exhibits AGG at room temperature without any additional heat treatment. Analysis by EBSD revealed oriented grain nucleation in a $\left\{11\overline{2}0\right\}〈0001〉$ direction from the initial $\left(0001\right)$ fibre texture which agrees with the maximum energy release model. New grains were oriented according to the minimal Young's modulus direction (c-axis), parallel to the shearing direction. The strain-induced dissolution of nanocrystalline Zn₃Ag precipitates was identified as the main driving force for AGG in this alloy. The strains necessary for the initiation and termination of AGG were determined as ~4.0 and ~5.0, respectively. The increase in solid-solution strengthening caused an increase in hardness from ~47 HK in the fine-grained centre to ~84 HK in the coarse-grained region. A Hall-Petch investigation revealed grain refinement softening below a grain size of 23 µm. These results provide the first comprehensive description of AGG in metallic materials processed by a severe plastic deformation method at room temperature.

使用扫描电子显微镜（SEM），电子背散射衍射（EBSD），高电子显微镜系统研究了通过施加高压扭转（HPT）产生的Zn-0.8Ag（wt％）合金中异常晶粒生长（AGG）分辨率透射电子显微镜（HR-TEM）和显微硬度测试。HPT变形合金在室温下显示出AGG，无需任何额外的热处理。EBSD的分析表明，在$\left\{11\overline{2}0\right\}〈0001〉$ 从最初的方向 $（0001）$符合最大能量释放模型的纤维质地。根据最小的杨氏模量方向（c轴），平行于剪切方向对新晶粒进行取向。应变诱导的纳米Zn _3的溶解Ag沉淀被确定为该合金中AGG的主要驱动力。确定起始和终止AGG所需的菌株分别为〜4.0和〜5.0。固溶强化的增加导致硬度从细粒中心的〜47 HK增至粗粒区域的〜84 HK。Hall-Petch研究表明，晶粒细化在23 µm以下的晶粒中软化。这些结果提供了在室温下通过严格的塑性变形方法加工的金属材料中AGG的首次综合描述。