浇铸温度对液-固铸轧1070A/7075铝合金复合板材界面组织与性能的影响

Effect of casting temperature on the interface microstructure and properties of liquid-solid cast-rolling 1070A/7075 aluminum alloy composite sheet

采用立式双辊铸轧机液-固铸轧1070A/7075铝合金复合板材,借助扫描电镜(SEM)、能谱仪(EDS)、硬度计和剪切机、拉伸试验机等检测仪器,探讨了1070A铝溶体浇铸温度对液-固铸轧1070A/7075铝合金复合板材界面组织与性能的影响。结果表明:随着浇铸温度的升高,复合板材界面处元素扩散宽度不断增大,复合板剪切强度不断增高,7075铝合金固态基板一侧的高硬度分布区域变窄。当浇铸温度为690℃时,复合板材界面无明显缺陷,元素扩散距离约为15μm,显微硬度变化趋势较为缓和,剪切强度达79.3 MPa,抗拉强度、屈服强度、伸长率分别达到139.6 MPa、70.3 MPa、24.2%。

The vertical twin-roll casting machine was used to prepare liquid-solid cast-rolling 1070A/7075 aluminum alloy composite sheet.By means of scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),microhardness,shear and tensile testers,the effect of casting temperature of aluminum melt on the interfacial microstructure and properties of solid-liquid cast-rolling 1070A/7075 aluminum alloy composite sheet were analyzed.The results show that with the increase of casting temperature,the diffusion width of interficial elements of the composite sheet increases,the shear strength of the composite sheet increases,and the high hardness distribution area on the 7075 aluminum alloy side of the solid substrate narrows.When the casting temperature is 690 ℃,there is no obvious defect at the interface of the composite sheet,the element diffusion distance is about 15 μm,the microhardness change trend is relatively moderate,the shear strength reaches 79.3 MPa,and the tensile strength,yield strength and elongation reach 139.6 MPa,70.3 MPa and 24.2%,respectively.