中文摘要：

通过光学显微镜、扫描电镜、显微硬度计及电化学测试,研究了热处理对Al-Zn-Mg-Cu合金的组织和性能的影响.结果表明,在410～490℃范围内,随着固溶温度的升高,粗大的平衡相逐渐回溶,合金经450℃固溶1h后,MgZn2相溶解比较充分,合金硬度逐渐增大,进一步提高固溶温度,合金硬度下降.450和470℃固溶处理后合金腐蚀电位的正移效果明显,说明晶界析出相越离散,则合金的耐蚀性越好,同时致密的合金组织有利于改善Al-Zn-Mg-Cu合金的抗高温氧化性能.

英文摘要：

The microstructures and properties of A1-Zn-Mg-Cu alloy under different heat treatment conditions were studied by optical microscope （OM）, scanning electron microscopy （SEM）, the microhardness tester and the electrochemical test. The results show that the re-dissolution of the bulky equilibrium phase of Al-Zn-Mg-Cu alloy gradually occurred with the increase of solution temperature within the range of 410-490℃. MgZn2 phase fully dissolved and the hardness of Al-Zn- Mg-Cu alloy gradually increased after 1 hour of solution treatment at 450℃, and the hardness decreased with the further increase of solution temperature. The corrosion potential after solution treatment at 450℃ and 470℃ was the most obvious positive shift. It is concluded that grain boundary precipitates is more discrete, corrosion resistance of beneficial to improve the high temperature oxidation alloy is better. And the dense microstructure is resistance.