Cu含量对Al-Cu-Li合金淬火敏感性的影响  

Effect of Cu content on quenching sensitivity of Al-Cu-Li alloy

作　　者：刘锦勋 李红英[1,2] 杨惠钧 林海涛 郑子樵[1] LIU Jinxun;LI Hongying;YANG Huijun;LIN Haitao;ZHENG Ziqiao(School of Materials Science and Engineering,Central South University,Changsha 410083,China;State Key Laboratory of Lightweight High-Strength Structural Materials,Central South University,Changsha 410083,China;Southwest Aluminum(Group)Co.,Ltd.,Chongqing 401326,China)

机构地区：[1]中南大学材料科学与工程学院,长沙410083 [2]中南大学轻质高强结构材料国家级重点实验室,长沙410083 [3]西南铝业(集团)有限责任公司,重庆401326

出　　处：《中国有色金属学报》2024年第5期1506-1518,共13页The Chinese Journal of Nonferrous Metals

摘　　要：采用薄板叠层末端淬火的方法,通过强度测试、连续冷却转变(CCT)和时间-温度-转化率(TTT)曲线计算及X射线衍射、扫描电镜、透射电镜等微观组织表征方法,研究了Cu含量(3.15%、3.63%和3.88%)对Al-Cu-Li合金淬火敏感性的影响,结合理论分析,从析出驱动力和形核位点的角度分析了Cu含量影响淬火敏感性的机理。结果表明:随着Cu含量的增加,晶格畸变能增加,Li的溶解度降低,淬火态合金中位错和残留第二相增多,含Li相的析出驱动力和非均匀形核位点增加,淬火沉淀相增多;随着临界冷却速率的增大,鼻尖温度孕育期缩短,强度残存率减小,Al-Cu-Li合金淬火敏感性提高。T8态合金强度受Cu含量和淬火速率共同作用,淬火速率较高时,主要受Cu含量的影响;淬火速率较低时,Cu含量的影响减小。The effects of Cu content(3.15%,3.63%and 3.88%)on the quenching sensitivity of Al-Cu-Li alloy were studied by means of strength test,continuous cooling transformation and time-temperature-transformation curves calculation and microstructure characterization methods such as X-ray diffraction,scanning electron microscopy and transmission electron microscopy.Combined with theoretical analysis,the mechanism of Cu content affecting quenching sensitivity was analyzed from the perspective of precipitation driving force and nucleation site.The results show that,with the increase of Cu content,the lattice distortion energy increases,the solubility of Li decreases,the dislocations and residual second phases in the quenched alloy increase,the driving force of precipitation and sites of heterogeneous nucleation of Li-containing phase increase,and the quenching-induced phase increases.When the critical cooling rate increases,the incubation period of nose tip temperature is shortened,the strength residual rate decreases,and the quenching sensitivity of Al-Cu-Li alloy increases.The strength of T8 alloy is affected by Cu content and quenching rate.It is mainly affected by Cu content when the quenching rate is high,and the influence of Cu content decreases when the quenching rate is low.

关 键 词：AL-CU-LI合金 CU含量 淬火敏感性 强度 淬火沉淀相 

分 类 号：TG146.2[一般工业技术—材料科学与工程]