(北京有色金屬研究總院 有色金屬制備加工國(guó)家重點(diǎn)實(shí)驗(yàn)室，北京 100088)
摘 要: 采用硬度、電導(dǎo)率、拉伸性能、撕裂性能等性能測(cè)試和差示掃描量熱(DSC)、透射電鏡(TEM)等分析方法研究單級(jí)時(shí)效和多級(jí)斷續(xù)時(shí)效對(duì)高Cu/Mg比Al-Cu-Mg-Ag-Zr合金組織和性能的影響。結(jié)果表明：與T6態(tài)合金相比，多級(jí)斷續(xù)時(shí)效處理在保持合金強(qiáng)度、硬度和電導(dǎo)率同時(shí)，顯著提高合金的斷裂韌性；160 ℃單級(jí)時(shí)效過(guò)程中，Ω和θ′ 相同時(shí)析出；斷續(xù)時(shí)效第一級(jí)和第三級(jí)時(shí)效的主要析出相與單級(jí)時(shí)效的類似，第二級(jí)低溫時(shí)效過(guò)程中，θ′ 相明顯析出，未出現(xiàn)明顯的Ω相析出特征。
關(guān)鍵字: 鋁合金；多級(jí)斷續(xù)時(shí)效；斷裂韌性；析出相
（State Key Laboratory of Nonferrous Metals and Processes,
General Research Institute for Nonferrous Metals, Beijing 100088, China）
Abstract:Hardness, electrical conductivity, tensile, tear test and differential scanning calorimetry (DSC), transmission electron microscopy were used to investigate the effect of single ageing and multi-step ageing process on the microstructure and properties of an Al-Cu-Mg-Ag-Zr alloy with high Cu/Mg ratio. The results show that comparing with the alloy at T6 condition, the hardness, strength and electrical conductivity of the alloy after multi-step ageing keeps unvaried, while the fracture toughness increases significantly. In the single ageing process, Ω and θ′ phases separate out simultaneously. At the first and third step of multi-step ageing, the characteristic of precipitates is not different from that of single ageing. But, θ′ phase separates out without significant characteristic of Ω phase at the second step of low temperature ageing.
Key words: aluminum alloys; multi-step ageing; fracture toughness; precipitates
