AlZn8Mg2Cu2合金50 mm热轧板固溶处理工艺研究

Study on solution treatment technology of AlZn8Mg2Cu2 alloy hot-rolled plate with 50 mm thickness

采用金相显微镜、扫描电镜、DSC曲线及焓值变化动力学曲线等方法,对AlZn8Mg2Cu2合金热轧板材进行分析,根据分析结果进行固溶处理工艺试验研究。结果表明:AlZn8Mg2Cu2合金热轧板材中含有S相(Al2CuMg)、难熔富Fe相(Al7Cu2Fe)、AlZnMgCu相;DSC分析显示,板材中存在475.66℃和482.94℃开始熔化的两种低熔点产物,对应的分别是AlZnMgCu相和Al2CuMg相;AlZn8Mg2Cu2合金50mm热轧板较适宜的固溶工艺参数为470℃3h,板材固溶处理并人工时效后,其综合性能满足标准要求。

Hot-rolled plate of A1Zn8Mg2Cu2 alloy was analyzed by the methods of metallographic microscope, SEM, DSC curve and kinetic curve of enthalpy change and so on. Based on the analysis results, the solution treatment process was studied. The results show that S phase （ A12 CuMg） , insoluble Fe-rich phase （ A17 Cu2 Fe） and AIZnMgCu phase can be found in the microstructure of AlZn8Mg2Cu2 alloy hot-rolled plate. DSC analysis indicates that two kinds of low melting point products commence melting at 475.66℃ and 482.94℃ exist in such plate, corresponding to A1ZnMgCu phase and Al2CuMg phase respectively. Solution treatment at 470℃3h is suitable for AlZn8Mg2Cu2 alloy plate with 50mm thickness. After solution treatment followed by aging treatment, the overall performance of such plate can meet the standard requirement.