摘要
通过维氏硬度测试、拉伸测试、剥落腐蚀与晶间腐蚀试验、扫描电镜（SEM）与透射电镜（TEM）分析等手段,研究了回归再时效（RRA）处理对Al-6Zn-2Mg-2Cu合金力学性能及耐腐蚀性能的影响。结果表明：经RRA处理后的Al-6Zn-2Mg-2Cu合金硬度、强度与单级时效（T6态）相当,均高于双级时效（T73态）。RRA 190℃×40 min处理,合金硬度达到最高,回归时间继续延长,硬度逐渐减小。Al-6Zn-2Mg-2Cu合金经不同时效处理后抗腐蚀性能由低到高依次为：T6、RRA 190℃×20 min、RRA 190℃×40 min、RRA 190℃×60 min、T73。RRA处理可保持Al-6Zn-2Mg-2Cu合金高强度的同时提高其抗腐蚀性能。经120℃×24 h＋190℃×40 min＋120℃×24 h的RRA处理后,合金硬度较高且腐蚀敏感性小,具有良好的综合性能。
The effects of retrogression and re-aging treatments （RRA） on mechanical properties and corrosion resistance of Al-6Zn-2Mg- 2Cu alloy were studied by means of hardness and tensile tests, intergranular and exfoliation corrosion tests, scanning electron microscopy （SEM） and transmission electron microscopy（TEM）. The results show that after RRA treatment, the hardness and strength of the Al- 6Zn-2Mg-2Cu alloy is similar to that of the single-stage aging treatment（T6 temper）, higher than that of the double-stage aging treatment （T73 temper）. The hardness of the alloy after RRA at 190℃ for 40 min reaches the peak value, with the increasing of the regression time, the hardness decreases gradually. After different aging processes, the corrosion resistance of the Al-6Zn-2Mg-2Cu alloy from low to high is as follows：T6, RRA at 190℃ for 20 min, RRA at 190℃ for 40 min, RRA at 190℃ for 60 rain, T73. The corrosion resistance of the Al-6Zn-2Mg-2Cu alloy can be improved by RRA treatment with its high strength unchanged. After RRA at 120 ℃ for 24 h and then at 190℃ for 40 min and last at 120℃ for 24 h, the alloy has higher hardness and less corrosion sensitivity, exhibits good comprehensive performance.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2018年第1期14-19,共6页
Transactions of Materials and Heat Treatment
基金
辽宁省自然科学基金(2013020083)
