(1. 中南大學 材料科學與工程學院，長沙 410083;
2. 中南大學 有色金屬材料科學與工程教育部重點實驗室，長沙 410012)
摘 要: 研究蠕變時效前預處理（15%預變形+100 ℃預時效5 h）對可熱處理強化2124鋁合金蠕變時效成形的影響。采用SEM分析、TEM分析以及測定電導率、維氏硬度和拉伸性能等手段，分析兩種不同初始狀態(tài)試樣經(jīng)過蠕變時效后的微結構和性能。結果表明：初始預處理降低了蠕變時效過程中蠕變初始階段的蠕變伸長率，但增大了穩(wěn)態(tài)蠕變階段的蠕變速率；初始預處理對基體中粗大Fe、Si相有一定的破碎作用，蠕變時效過程中，粗大粒子在蠕變應力作用下進一步被破碎；預處理能夠改善第二相的析出形態(tài)和分布，使析出相分布均勻；預處理試樣的電導率比未預處理試樣的電導率高，其硬度和強度也較高，但伸長率較低。
關鍵字: 蠕變時效；預處理；微結構；力學性能
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Nonferrous Materials Science and Engineering, Ministry of Education,
Central South University, Changsha 410012, China）
Abstract:The effect of pre-treatment（15% pre-deformation +100 ℃ pre-aging for 5 h）on creep age forming of aluminum alloy 2124 sheets, which can be enhanced by heat treatment, was investigated. The microstructures and properties of two sheets with different pre-treatments were analysed by means of SEM, TEM and measuring the electrical conductivity, Vickers hardness and tensile performance. The results show that the pre-treatment reduces the elongation of the initial stage of creep, but increases the steady-state creep rate; the coarse Fe and Si second phase particles are crushed to certain degree by the pre-treatment, and such coarse particles are further broken down by the subsequent creep stress. The morphology and distribution of the precipitated second phase particles are also improved by pre-treatment. The pre-treated sample depicts higher electrical conductivity, hardness and strength but smaller elongation rate than the non-pre-treated one.
Key words: creep aging; pre-treatment; microstructure; mechanical property
