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

作　　者：王熠璇 贾丽娜[1] 张虎[1] Wang Yixuan;Jia Lina;Zhang Hu(Department of Materials Science and Engineering,Beihang University,Beijing 100191,China)

机构地区：[1]北京航空航天大学材料科学与工程学院,北京100191

出　　处：《稀有金属材料与工程》2021年第11期3910-3916,共7页Rare Metal Materials and Engineering

基　　金：National Key R&D Program of China(2016YFB0300900)。

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λ_(1)、二次枝晶臂间距λ_(2)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。The Al-Zn-Mg-Cu alloy with high Zn content was cast at different temperature gradients by directional solidification.The primary dendrite arm spacingλ_(1),the secondary dendrite arm spacingλ_(2),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.

关 键 词：AL-ZN-MG-CU合金 定向凝固 温度梯度 枝晶臂间距 理论模型 

分 类 号：TG146.21[一般工业技术—材料科学与工程]