(東北大學(xué) EPM重點(diǎn)實(shí)驗(yàn)室, 沈陽(yáng) 110004)
摘 要: 采用力學(xué)性能和電導(dǎo)率測(cè)試及透射電鏡組織觀察的方法, 研究了7050合金擠壓帶板的單級(jí)時(shí)效、 雙級(jí)時(shí)效及兩級(jí)時(shí)效之間處理?xiàng)l件對(duì)合金組織和性能的影響。 結(jié)果表明： 7050合金在120 ℃時(shí)效有很高的抗過(guò)時(shí)效能力, 抗拉強(qiáng)度超過(guò)619 MPa, 但電導(dǎo)率較低僅為32.3％IACS； 采用第二級(jí)時(shí)效溫度為165 ℃的雙級(jí)時(shí)效, 合金可獲得強(qiáng)度為551 MPa和電導(dǎo)率為40.6％IACS的配合；雙級(jí)時(shí)效過(guò)程的兩級(jí)時(shí)效之間處理?xiàng)l件對(duì)合金的強(qiáng)度有明顯的影響, 間斷時(shí)效和第一級(jí)時(shí)效后快冷有利于提高合金的強(qiáng)度；經(jīng)過(guò)第一級(jí)時(shí)效后空冷再進(jìn)行165 ℃、 16 h時(shí)效, 合金的強(qiáng)度和電導(dǎo)率分別為559 MPa和40.2％IACS。
關(guān)鍵字: 7050鋁合金； 雙級(jí)時(shí)效； 擠壓帶板； 電導(dǎo)率； 析出相
properties of 7050 aluminium alloy
（The Key Laboratory of Electromagnetic Processing of Materials,
Mnistry of Education, Northeastern University, Shenyang 110006, China）
Abstract: The effects of single aging, duplex aging and conditions between the first and second step agings on the microstructures and properties of the extruded plate of 7050 aluminium alloy were investigated, by means of TEM, tensile and conductivity tests. The results show that 7050 aluminium alloy aged at 120 ℃ can obtain tensile strength of 619 MPa and conductivity of 32.3％IACS, and its overaging at that temperature needs long time. 7050 aluminium alloy after duplex aging with the second-step aging at 165 ℃ can obtain the combinations of the tensile strength of 551 MPa and the conductivity of 40.6％IACS. Obvious effects of the treatment conditions exist between the first and second step agings on the tensile strength of 7050 aluminium alloy during duplex aging. The tensile strength of 7050 aluminium alloy can be increased as stop aging or quick cooling after the first step aging during duplex aging. 7050 alloy can obtain tensile strength of 559 MPa and conductivity of 40.2％IACS when it is aged at 165 ℃ for 16 h after air cooling following the first step aging.
Key words: 7050 aluminium alloys; duplex aging; extruded plate; conductivity; precipitates
