中文摘要：

将7075铝合金经过先冷轧（Cold rolling,CR）后T6热处理（CR＋T6）和先T6热处理后冷轧（T6＋CR）两种方式进行处理,采用金相显微镜、透射电镜,结合材料拉伸力学性能分析研究了变形和热处理相结合对Al-Zn-Mg-Cu合金的影响。结果表明,先冷轧后T6热处理对合金抗拉强度和延伸率影响不大,而先T6热处理后冷轧的试样屈服强度和抗拉强度随着变形量的增大显著提高。T6＋40%（T6＋CR的最优参数）与60%＋T6（CR＋T6的最优参数）的试样相比消耗的能量少且强度和塑性都更好。不同程度的晶界强化和位错强化是促使CR＋T6和T6＋CR处理试样力学性能改变的主要原因。

英文摘要：

In order to examine the combined effect of plastic deformation and the T6 treatment on Al-Zn-Mg-Cu alloys,a 7075 Al alloy was subjected to cold-rolling（CR）deformation and T6heat-treatment（T6）in two different routes of CR＋T6（CR followed with T6）and T6＋CR（T6treatment followed with CR）,respectively,and characterized by optical microscopy,transmission electron microscope,and mechanical tensile property measurement.The results show that the cold-rolling before T6 heat treatment has less influences on the tensile strength and elongation of the CR＋T6samples.While the yield strength and ultimate tensile strength of T6＋CR samples are remarkably improved with increasing the deformation,and the T6＋40% deformation（the optimized T6＋CR）sample exhibits superior strength with adequate plasticity,with less energy consumption compared with the 60% deformation T6sample（the optimized CR＋T6）.Microstructure investigation reveals that the grain-boundary strengthening and dislocation strengthening are the primary reasons for the improved mechanical properties of CR＋T6and T6＋CR samples.