(1. 中南大學(xué) 材料科學(xué)與工程學(xué)院，長(zhǎng)沙 410083；
2. 中南大學(xué) 有色金屬材料與工程教育部重點(diǎn)實(shí)驗(yàn)室，長(zhǎng)沙 410083)
摘 要: 利用硬度、電導(dǎo)率與拉伸性能測(cè)試，結(jié)合差示掃描量熱法(DSC)和透射電鏡(TEM)研究預(yù)時(shí)效溫度和回歸加熱速率對(duì)7055鋁合金力學(xué)性能和電導(dǎo)率的影響，并討論各RRA制度下微觀組織的變化。結(jié)果表明：由于7055鋁合金中厚板在回歸加熱過(guò)程中存在慢速升溫過(guò)程，近峰時(shí)效作為預(yù)時(shí)效制度更適合7055鋁合金中厚板的回歸再時(shí)效處理。經(jīng)過(guò)(105 ℃，24 h) (190 ℃，50 min)+(120 ℃，24 h)的三級(jí)時(shí)效處理，7055鋁合金中厚板強(qiáng)度和電導(dǎo)率優(yōu)于T6和T73狀態(tài)的綜合性能。
關(guān)鍵字: 預(yù)時(shí)效溫度；回歸；加熱速率；7055鋁合金；中厚板
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education,
Central South University, Changsha 410083, China）
Abstract:The effect of pre-aging temperature and retrogression heating rate on the mechanical properties and electrical conductivity of the RRA treated 7055 aluminium alloy were investigated by hardness, electrical conductivity, tensile properties test, differential scanning calorimetry (DSC) and transmission electron microscope (TEM). The microstructures under various RRA treated samples were discussed. The results reveal that, near peak aged state, the pre-aging treatment is more applicable to industrial processing due to the slow retrogression heating rates in 7055 aluminium alloy middle thick plate. After (105 ℃, 24 h) (190 ℃, 50 min)+(120 ℃, 24 h) treating, the 7055 aluminum alloy possess a better combination of both strength and electrical conductivity than those of T6 and T73 state.
Key words: pre-aging temperature; retrogression; heating rate; 7055 aluminium alloy; middle thick plate
