(1. 北京有色金屬研究總院 有色金屬材料制備加工國家重點實驗室，北京100088；
2. 北京科技大學(xué) 新金屬材料國家重點實驗室，北京 100083)
摘 要: 采用力學(xué)性能和電導(dǎo)率測試以及透射電子顯微鏡組織等觀察分析新型7056鋁合金雙級時效制度下的性能和顯微組織。結(jié)果表明：第二級時效處理后，合金基體沉淀析出相長大粗化，晶界析出相逐漸呈斷續(xù)分布狀態(tài)，無析出帶隨時間的延長而變寬；經(jīng)第二級150 ℃、12 h時效后，合金由GP區(qū)和η相構(gòu)成，析出相的尺寸為7~9 nm，并出現(xiàn)明顯的無析出帶；隨著第二級時效時間的延長，合金電導(dǎo)率逐漸升高，屈服強度先增大后減小；合金經(jīng) (110 ℃、6 h)+(150 ℃、14 h)雙級時效處理后，屈服強度達到650 MPa，電導(dǎo)率為21.72 MS/m，表現(xiàn)出優(yōu)異的綜合性能。
關(guān)鍵字: 7056鋁合金；雙級時效；顯微組織；性能
（1. State Key Laboratory for Fabrication and Processes of Nonferrous Metals,
General Research Institute for Nonferrous Metals, Beijing 100088, China;
2. State Key Laboratory for Advanced Metals and Materials,
University of Science and Technology, Beijing 100083, China）
Abstract:The properties and microstructure of two-step aged Al-9.73Zn-1.98Mg-1.76Cu aluminum alloy were studied by using of measuring properties and electrical conductivity and TEM analysis. The results show that matrix precipitates growth and coarsening, grain boundary phases distribute discontinuous, and precipitation free zone (PFZ) become broader with increasing the second ageing time. The second (150 ℃, 12 h) aged alloy consists of GP zone and η′ phase, the size of precipitates is between 7-9 nm, and PFZ can be found apparently. The electrical conductivity increases with increasing the second step ageing time, while yield strength increases firstly, and then reduces. Alloy aged at (110 ℃, 6 h)+(150 ℃, 14 h) can obtain the yield strength of 650 MPa, and electrical conductivity of 21.72 MS/m, which shows good performance matching.
Key words: 7056 aluminum alloy; two-step ageing; microstructure; property
