(1. 中南大學(xué)輕合金研究院，長沙 410083；
2. 中南大學(xué)粉末冶金國家重點實驗室，長沙 410083；
3. 首都航天機械公司，北京 100076)
摘 要: 采用硬度、電導(dǎo)率、力學(xué)拉伸、慢應(yīng)變速率拉伸試驗及透射電鏡等測試分析方法，研究雙級時效對7085鋁合金組織和性能的影響。結(jié)果表明：預(yù)時效熱處理主要析出相為GP 區(qū)和η′相，預(yù)時效時間對合金硬度和電導(dǎo)率的影響較小。隨著第二級時效時間的延長，合金的抗拉強度和屈服強度先增大后減小，電導(dǎo)率和抗應(yīng)力腐蝕性能提高，晶界析出相由連續(xù)分布變?yōu)榉沁B續(xù)分布。第二級時效溫度越高，合金強度隨時效時間的延長，降低得越顯著。采用(110℃, 6h)+(160℃, 12h)雙級時效熱處理，合金的抗拉強度、屈服強度、伸長率及電導(dǎo)率分別為515MPa、487MPa、11.7%、38%(IACS)。
關(guān)鍵字: 7085鋁合金；雙級時效；顯微組織；性能
（1.Light Alloy Research Institute，Central South University, Changsha 410083, China;
2.State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
3. Capital Aerospace Machinery Company, Beijing 100076, China）
Abstract:The effect of two-step aging treatment on microstructure and properties of 7085 aluminum alloy was investigated by hardness,conductivity, mechanical testing, slow strain rate testing and transmission electron microscopy. The results show that the GP zones andη′phase are the mainly precipitation phases of pre-aging, and the pre-aging time is less impact on the hardness and electrical conductivity. The strength after two-step aging process first increases, and then decreases, while the ability of stress corrosion resistance increases with the extension of the second step of aging time. With the size of grain boundary precipitates coarsening, and the distribution of grain boundary precipitates from continuous to non-continuous. The strength of the alloy significantly decreases with the increases of the second step aging temperature. The optimal of the two-step aging process is (110 ℃, 6 h)+(160 ℃, 12 h), the tensile strength, yield strength, elongation and conductivity of alloy are 515MPa, 487MPa, 11.7%, 38%(IACS), respectively.
Key words: 7085 aluminum alloy; two-step aging; microstructure; property
