Abstract

In the present study, a Mg–8Al–0.5Zn (AZ80) Mg alloy was subjected to water quenching and furnace cooling from the solution treatment temperature of 390 °C. Subsequently, all the samples were subjected to aging treatment at 250 °C. The precipitation behavior, aging response and fracture phenomenon of the AZ80 Mg alloy were evaluated to establish the correlation among the cooling rates after solution treatment, microstructural features and mechanical properties. Scanning electron microscopy depicted a very distinct precipitation behavior of aged specimens. The observed variation in the aging curves was rationalized based on this. Fractographic analysis on the as-solutionized and aged alloys revealed that the initiation of fracture (i.e., intergranular or transgranular) was dictated by the presence of microstructural features, such as precipitates (continuous and discontinuous), twins and grain boundaries. The fracture strain was correlated with the number density and size of voids formed during tensile loading.

Graphic Abstract

中文翻译：

---

固溶处理温度下的冷却速率对Mg-8Al-0.5Zn合金时效响应和断裂行为的影响

摘要

在本研究中，从390°C的固溶处理温度对Mg-8Al-0.5Zn（AZ80）Mg合金进行了水淬和炉冷。随后，所有样品在250℃下进行时效处理。对AZ80镁合金的析出行为，时效响应和断裂现象进行了评估，以建立固溶处理后的冷却速率，微观组织和力学性能之间的关系。扫描电子显微镜描绘了老化样品的非常不同的沉淀行为。基于此合理化观察到的老化曲线变化。对固溶态和时效合金的分形分析表明，断裂的发生（即晶间或跨晶）是由微观结构特征决定的，例如沉淀（连续和不连续），孪晶和晶界。断裂应变与拉伸载荷过程中形成的空隙的数量密度和大小相关。

图形摘要