温度梯度对定向凝固Al-Zn-Mg-Cu合金微观组织和硬度的影响

Influence of Temperature Gradient on Microstructure and Microhardness of Directionally Solidified Al-Zn-Mg-Cu Alloy

摘要:

采用定向凝固方法制备不同温度梯度下的高锌Al-Zn-Mg-Cu合金，表征了该合金的一次枝晶臂间距λ₁、二次枝晶臂间距λ₂以及其维氏硬度。在此基础上，采用线性回归和曲线拟合分析方法建立了温度梯度、枝晶间距和显微硬度之间的关系，结果与枝晶生长理论模型吻合，并获得了高锌Al-Zn-Mg-Cu合金的凝固特征参数，同时分析了温度梯度对显微硬度的影响机制。研究结果对高锌Al-Zn-Mg-Cu合金制备工艺优化有指导作用。

Abstract:

The Al-Zn-Mg-Cu alloy with high Zn content was cast at different temperature gradients by directional solidification. The primary dendrite arm spacing λ₁, the secondary dendrite arm spacing λ₂, and the Vickers hardness of specimens were characterized. Based on the experiment results, the relationship among temperature gradient, dendritic arm spacing, and microhardness was determined by linear regression analysis and curve fitting analysis. The results are in agreement with the dendritic growth theoretical models, and the solidification parameters of Al-Zn-Mg-Cu alloy were obtained. In addition, the influence mechanism of temperature gradient on microhardness was analyzed. The results have a guidance function on the optimization of preparing methods of Al-Zn-Mg-Cu alloy with high zinc content.