微量Sc对高强铝合金铸态组织性能的影响

Influence of Micro-Sc on Casting Microstructures and Mechanical Properties of High Strength Aluminum Alloy

目的研究Sc对某7系铝合金铸态组织性能以及对合金主要元素分布情况的影响。方法在某7系铝合金中添加微量Sc,采用金相显微镜、硬度测试等实验方法,研究了合金铸态组织与性能;通过SEM和EDS分析了合金主要元素分布情况。结果添加0.2%的Sc的合金,晶粒尺寸从106μm细化到41μm;Sc的添加使硬度得到了一定程度的改善,增大了Cu元素的枝晶偏析,而对合金基体中Zn和Mg等合金元素枝晶偏析影响不大。结论添加微量Sc,可以得到细小、圆整、均匀的铸态组织,合金主要元素的分布也得到改善。

The aim of this study was to investigate the effect of Sc on the microstructure and the distribution of the main elements of the alloy in a 7 series aluminum alloy. After addition of Micro-Sc in a 7 series Aluminum alloy,the microstructure and properties of the 7 series Al alloy was investigated by means of optical microscope and hardness test. The distribution of major elements of the alloy was analyzed by SEM and EDS. The grain size of the alloy containing 0. 2% Sc was refined from 106 μm to 41 μm. The addition of Sc improved the hardness and increased the dendrite segregation of Cu element,and had little effect on the dendrite segregation of Mg and Zn in the alloy. The small,round and uniform cast structure can be obtained by addition of Sc and the distribution of major elements of the alloy was also improved.