1、二次枝晶臂間距λ2以及其維氏硬度。在此基礎上，采用線性回歸和曲線擬合分析方法建立了溫度梯度、枝晶間距和顯微硬度之間的關系，結果與枝晶生長理論模型吻合，并獲得了高鋅Al-Zn-Mg-Cu合金的凝固特征參數(shù)，同時分析了溫度梯度對顯微硬度的影響機制。研究結果對高鋅Al-Zn-Mg-Cu合金制備工藝優(yōu)化有指導作用。;The Al-Zn-Mg-Cu alloy with high Zn content was cast at different temperature gradients by directional solidification. The primary dendrite arm 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."/>