中文摘要：

采用直接冷却铸造法制备6009/7050复层板坯。通过对该板坯先后进行均匀化退火、热轧和T6热处理,研究其对复层板坯组织和性能的影响。研究结果表明,铸态下该复层板坯的平均扩散层厚度约为400μm,扩散层厚度是由锌、铜、镁和硅的互扩散决定的。拉伸试验表明,复层板坯实现了良好的冶金复合,因为均匀化后的拉伸试样全部在较软的6009合金侧发生断裂。经过均匀化退火加热轧处理,平均扩散层厚度降低到100μm,同时7050合金侧的网状结构转变为分散的块状相。再经过T6热处理后,平均扩散层厚度增加为200μm,并且7050合金侧和6009合金侧的维式硬度均有明显地提高。经过热轧和T6热处理后,6009/7050复层铸坯的层状结构被保留下来。

英文摘要：

6009/7050 alloy bimetal slab was prepared by a direct-chill (DC) casting process. Homogenizing annealing, hot rolling and T6 treatment were successively performed and their effects on microstructure and properties of the slab were studied. The results reveal that the average diffusion layer thickness of as-cast slab, determined by interdiffusion of elements Zn, Cu, Mg and Si, was about 400 μm. Excellent metallurgical bonding was achieved because all tensile samples fractured on the softer 6009 alloy side after homogenizing annealing. After homogenizing annealing plus rolling, the average diffusion layer thickness decreased to 100 μm, while the network structure of 7050 alloy side transformed to dispersive nubby structure. Furthermore, subsequent T6 treatment resulted in diffusion layer thickness up to 200 μm and an obvious increase of the Vickers hardness for both 7050 and 6009 sides. The layered structure of the as-cast 6009/7050 bimetal is retained after hot rolling and T6 treatment.