(1. 中南大學 材料科學與工程學院，長沙 410083；
2. 湖南人文科技學院 機電工程系，婁底 417000；
3. 中南大學 輕合金研究院，長沙 410083)
摘 要: 通過拉伸實驗、慢應變速率實驗、剝落腐蝕實驗、掃描電鏡和透射電鏡觀察，研究新型熱機械處理對Al-Zn-Mg-Cu合金顯微組織及性能的影響。結(jié)果表明：冷變形最終熱機械處理能夠使合金在塑性不顯著降低的情況下，提高合金的強度，溫變形最終熱機械處理能有效彌補常規(guī)最終熱機械處理后伸長率較低的缺陷，同時能有效改善合金的抗剝落腐蝕性能；回歸后冷變形可提高合金強度，但降低了合金的伸長率；回歸后溫變形處理能使合金獲得良好的綜合性能，如力學性能、抗應力腐蝕性和抗剝蝕性能。新型熱機械處理改善合金性能的機理是合金晶粒形態(tài)、位錯、初生相以及析出相等顯微組織結(jié)構的協(xié)同作用。
關鍵字: 高強鋁合金；時效；熱機械處理；應力腐蝕
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Department of Mechanical and Electrical Engineering,
Hunan University of Humanities Science and Technology, Loudi 417000, China;
3. Light Alloy Research Institute, Central South University, Changsha 410083, China）
Abstract:The effects of new thermomechanical treatment (TMT) on the microstructure and properties of Al-Zn-Mg-Cu alloy were studied by tensile test, slow strain rate tensile test (SSRT)，exfoliation corrosion test (EXCO), scanning electron microscopy and transmission electron microscopy. The results indicate that the cold deformation final thermomechanical treatment (FTMTc) process can significantly increase the strength of the alloy without obvious plasticty loss，and warm deformation find thermomechanical treatment (FTMTw) at 200 ℃ can simultaneously improve the elongation and EXCO resistance. Cold rolling after regression (RRCA) can obtain high strength but low elongation, while warm rolling after regression (RRWA) can obtain good mechanical properties and a good combination of stress corrosion resistance (SCR) and exfoliation corrosion resistance. The mechanism of the new TMT process that improves the properties of the alloy is the synergistic effect of composite structures, such as grain structure, dislocations, as well as the size and distribution of primary phase and precipitate phase.
Key words: high strength aluminum alloy; ageing; thermomechanical treatment; stress corrosion
