(1. 常州大學(xué) 材料科學(xué)與工程學(xué)院，常州213164；
2. 常州大學(xué) 江蘇省材料表面科學(xué)與技術(shù)重點實驗室，常州 213164)
摘 要: 采用拉伸測試、加速腐蝕試驗、掃描電鏡(SEM)及透射電鏡(TEM)觀察，研究了120、140、160 ℃時效對固溶處理+冷軋Al-Cu-Li合金拉伸性能和晶間腐蝕(IGC)敏感性的影響。結(jié)果表明：時效過程中，合金強(qiáng)度和伸長率呈現(xiàn)先增加后減小的變化趨勢；時效合金拉伸斷口形貌上沿晶斷裂與穿晶斷裂二者并存，且隨著時效時間延長，沿晶斷裂比例逐漸增加；欠時效合金發(fā)生晶間腐蝕，而峰值時效及過時效合金轉(zhuǎn)為孔蝕。上述變化與位錯和析出特征的時效變化密切相關(guān)，且隨著時效溫度升高而加快。經(jīng)(520 ℃, 1 h)固溶處理+60%壓下量冷軋+(160 ℃, 12 h)時效處理，合金綜合性能較優(yōu)，抗拉強(qiáng)度、屈服強(qiáng)度和伸長率分別為582 MPa、540 MPa和4.7%，且無IGC敏感性，最大腐蝕深度約55 μm。
關(guān)鍵字: Al-Cu-Li合金；冷軋；時效；拉伸性能；晶間腐蝕敏感性
（1. School of Materials Science and Engineering, Changzhou University, Changzhou 213164, China;
2. Jiangsu Key Laboratory of Materials Surface Science and Technology, Changzhou University, Changzhou 213164, China）
Abstract:The effects of ageing at 120, 140 and 160 ℃ on tensile properties and intergranular corrosion (IGC) sensitivity of the solution treated and cold rolled Al-Cu-Li alloy were investigated by tensile test, accelerating corrosion test, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that both the strength and elongation of the aged alloy first increase and then decrease during ageing process. The intergranular and transgranular fractures coexist on the fractographies of the aged alloys, and the intergranular one increases with the increase in ageing time. The underaged alloy is susceptible to IGC, whereas the peak-aged and overage alloys exhibit pitting corrosion (PC). The above change trend is related closely to the dislocations and precipitates during ageing, and furthermore becomes faster with increasing the ageing temperatures. After solution treatment (520 ℃, 1 h)+60% reduction cold rolling+artificial ageing (160 ℃, 12 h), the alloy has excellent comprehensive performance, the tensile strength, yield strength and elongation are 582 MPa, 540 MPa and 4.7%, respectively, and the alloy has low IGC sensitivity with the maximum corrosion depth of about 55 μm.
Key words: Al-Cu-Li alloy; cold rolling; ageing; tensile property; intergranular corrosion sensitivity
