(1. 中國航空制造技術(shù)研究院 材料應(yīng)用研究部，北京 100024；
2. 清華大學(xué) 材料學(xué)院，北京 100084；
3. 北京航空航天大學(xué) 材料科學(xué)與工程學(xué)院，北京 100083)
摘 要: 研究了時(shí)效前的預(yù)拉伸變形量對噴射成形2195鋁鋰合金時(shí)效析出行為及力學(xué)性能的影響規(guī)律。結(jié)果表明：2195合金經(jīng)固溶處理后直接時(shí)效，組織以δ′(Al3Li)相+少量T1(Al2CuLi)相為主，晶界處分布著大量斷續(xù)分布的顆粒析出相組織(富AlCu相及AlCuFe相)。時(shí)效前的預(yù)拉伸變形在合金基體中引入的大量位錯(cuò)成為T1相、θ′相的有效形核點(diǎn)，顯著促進(jìn)T1相和θ′相晶內(nèi)均勻、細(xì)小彌散析出，并降低晶界無析出帶寬度，形成以T1、δ′相、θ′相為主的混合析出相組織。力學(xué)性能測試結(jié)果表明：當(dāng)熱處理工藝為(510 ℃，2 h)固溶處理+3%預(yù)拉伸+(155 ℃，24 h)時(shí)效處理，噴射成形2195鋁鋰合金室溫抗拉強(qiáng)度約為(663±1) MPa，屈服強(qiáng)度約為(647±1) MPa，伸長率為(10.4±0.6) %，能夠獲得良好的強(qiáng)韌性匹配。
關(guān)鍵字: 噴射成形；2195鋁鋰合金；形變熱處理；時(shí)效析出相；力學(xué)性能
（1. Department of Materials Application Research, AVIC Manufacturing Technology Institute, Beijing 100024, China;
2. School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China;
3. College of Materials Science and Engineering, Beihang University, Beijing 100083, China）
Abstract:The effect of pre-stretch on the precipitation behavior and the mechanical properties of spray formed 2195 Al-Li alloy were studied. The results shows that lots of δ′(Al3Li) + less amount of T1(Al2CuTi) phases can be observed in the microstructure of 2195 alloy after solution and aging treatment, accompany with many discontinuous grain precipitates. The dislocations increase significantly in the 2195 alloy with the introduction of pre-stretching deformation before aging treatment, which can act as effective nucleation sites of T1 and θ′ phase causing T1 and θ′ phase size decreasing and uniform dispersion. Meanwhile, the microstructure has a mixed precipitate, such as T1, δ′ and θ′ phase, and with PFZ decreasing. The results of mechanical properties showed that 2195 Al-Li alloy will have a good balance between the strength and toughness under the heat treatment of (510 ℃, 2 h) solid solution + 3% pre-stretching + (155 ℃, 24 h) aging treatment. A good balance between strength and plasticity can be reached with the tensile strength of (663±1) MPa, the yield strength of (647±1) MPa and the elongation of (10.4±0.6) %.
Key words: spray forming; 2195 Al-Li alloy; thermo-mechanical treatment; precipitated phase; mechanical property
