(1. 常州大學(xué) 材料科學(xué)與工程學(xué)院,常州 213164;2. 中南大學(xué) 材料科學(xué)與工程學(xué)院,長沙 410083;
3. 常州大學(xué) 常州市先進(jìn)金屬材料重點實驗室,常州 213164)
摘 要: 采用差示掃描量熱法(DSC)研究了Al-Mg-Si和Al-Mg-Si-Cu鋁合金的連續(xù)升溫時效析出行為,并結(jié)合JMA方程分析Cu對該合金時效析出動力學(xué)的影響,計算出各種亞穩(wěn)相析出動力學(xué)參數(shù),進(jìn)而得出各相析出的相關(guān)動力學(xué)表達(dá)式及TTT 曲線。結(jié)果表明:Cu顯著地提高了Al-Mg-Si合金的時效硬化效果和速率,這與Cu的添加降低了析出激活能密切相關(guān);Al-Mg-Si合金原子團(tuán)簇、GP區(qū)、β〞和β'的激活能分別為(67.3±1.5)、(96.9±3.5)、(106.6±3.1)和(158.9±3.9) kJ/mol;而Al-Mg-Si-Cu鋁合金原子團(tuán)簇、GP區(qū)、β〞、β'、Q'和Q相的激活能分別為(62.0±1.8)、(87.8±3.2)、(97.7±3.1)、(137.0±4.2)、(125.5±4.3)和(266.7±5.4) kJ/mol。
關(guān)鍵字: Al-Mg-Si-(Cu)鋁合金;析出動力學(xué);差熱分析法;TTT曲線
Al-Mg-Si-(Cu) aluminum alloys during continuous heating
(1. School of Materials Science and Engineering, Changzhou University, Changzhou 213164, China;
2. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
3. Key Laboratory of Advanced Metallic Materials of Changzhou City,
Changzhou University, Changzhou 213164, China)
Abstract:During continuous heating, differential scanning calorimetry (DSC) and micro-hardness test were used to study precipitation behaviors of Al-Mg-Si and Al-Mg-Si-Cu alloys. The influence of Cu on the precipitation kinetics of Al-Mg-Si alloy was analyzed. The kinetic parameters of metastable phases in Al-Mg-Si-(Cu) alloy were obtained by using Avrami-Johnson-Mehl (AJM) equation. TTT curves and the kinetic expresses of metastable phases for Al-Mg-Si-(Cu) alloy were further gained. The results show that the addition of Cu enhances the age-hardening effect and precipitation kinetics, which may be due to the decrease of precipitation activation energy caused by the addition of Cu. The average activation energies associated with the precipitation of Si/Mg/Si-Mg clusters, GP-zones, β〞and β′ phases in Al-Mg-Si alloy are (67.3±1.5), (96.9±3.5), (106.6±3.1) and (158.9±3.9) kJ/mol, respectively. The average activation energies associated with the precipitation of Si/Mg/Si-Mg clusters, GP-zones, β′′ , β′ , Q′ and Q phases for Al-Mg-Si-Cu alloy are (62.0±1.8), (87.8±3.2), (97.7±3.1), (137.0±4.2), (125.5±4.3) and (266.7±5.4) kJ/mol, respectively.
Key words: Al-Mg-Si-(Cu) aluminum alloy; precipitation kinetics; differential scanning calorimetry (DSC); TTT curves


