(中南大學(xué) 機(jī)電工程學(xué)院 高性能復(fù)雜制造國家重點(diǎn)實(shí)驗(yàn)室，長沙 410083)
摘 要: 采用拉伸測試、維氏硬度測試和透射電鏡分析等方法研究實(shí)驗(yàn)應(yīng)力和時(shí)效時(shí)間對2524鋁合金蠕變時(shí)效行為的影響。結(jié)果表明：時(shí)效時(shí)間和試驗(yàn)應(yīng)力對材料的成形與微觀組織均有較大的影響，應(yīng)力越大、時(shí)間越長，蠕變行為越明顯；在190 ℃溫度下，試驗(yàn)應(yīng)力為180 MPa，時(shí)效時(shí)間約為12 h時(shí)，材料的硬度和強(qiáng)度趨近于峰值；TEM分析表明，合金板材強(qiáng)度和伸長率的差別主要由時(shí)效后強(qiáng)化相S′相和S″相的尺寸和分布密度決定；采用線性回歸方法獲得合金在190 ℃下穩(wěn)態(tài)蠕變速率與實(shí)驗(yàn)應(yīng)力的本構(gòu)關(guān)系。
關(guān)鍵字: 2524鋁合金；蠕變時(shí)效成形；力學(xué)性能；微觀組織；本構(gòu)關(guān)系
（State Key Laboratory of High Performance and Complex Manufacturing,
School of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China）
Abstract:The creep age forming effects of 2524 aluminum alloy at different stresses and aging times were investigated through tensile performance, Vickers hardness and TEM. The results show that the aging time and stress have great effect on not only creep behavior but also microstructure of 2524 aluminum alloy. And the creep behavior will become stronger with heavier stress and longer time. The hardness and strength of material will tend to be peak at 190 ℃ when the test-stress reaches 180 MPa and ageing time is 12 h. It can be concluded that the differences of strength and elongation of the alloy plate are determined by the size and distribution of S″ and S′ phase. Finally, the constitutive relationship between the steady creep rate and stress of 2524 aluminum alloy at 190 ℃ is obtained by linear regression.
Key words: 2524 aluminum alloy; creep age-forming; mechanical properties; microstructure; constitutive relationship
