Improvement of strength and ductility of Al-Cu-Li alloy through cryogenic rolling followed by aging  

采用低温冷轧+时效工艺提高Al-Cu-Li合金的强度及塑性（英文）

作　　者：Yan-jun DENG Guang-jie HUANG Ling-fei CAO Xiao-dong WU Li HUANG Ming-yong XIA Qing LIU 邓燕君;黄光杰;曹玲飞;吴晓东;黄利;夏明勇;刘庆(重庆大学材料科学与工程学院,重庆400044)

机构地区：[1]College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China

出　　处：《Transactions of Nonferrous Metals Society of China》2017年第9期1920-1927,共8页中国有色金属学报（英文版）

基　　金：Projects (106112015CDJXZ138803,106112015CDJXY130003) supported by the Fundamental Research Funds for the Central Universities,China;Project (51421001) supported by National Natural Science Foundation of China

摘　　要：To develop an improved approach in achieving an excellent combination of high strength and ductility,the solutionized Al?Cu?Li plates were subjected to rolling at cryogenic and room temperatures,respectively,to a reduction of83%,followed by aging treatment at160°C.The results indicate that Al?Cu?Li alloys through cryogenic rolling followed by aging treatment possess better mechanical properties.Rolling at cryogenic temperature produces a high density of dislocations because of the suppression of dynamic recovery,which in turn promotes the precipitation of T1(Al2CuLi)precipitates during aging.Such high density of T1precipitates enable effective dislocation pinning,leading to an increase in strength and ductility.In contrast,room temperature rolled alloys after aging treatment exhibit lower strength and ductility due to low density of T1precipitates in the grain interior and high density of T1precipitates around subgrain boundaries.为获得可提高Al-Cu-Li合金强度和塑性的加工工艺,比较如下两种工艺:固溶后的合金板材分别在低温(液氮温度)及室温下轧制变形(变形量达83%),随后在160°C下进行人工时效。结果表明,在低温冷轧+时效工艺条件下得到的Al-Cu-Li合金具有更优的力学性能。在低温冷轧后由于动态回复的抑制会产生大量位错,这将促进T_1相(Al_2CuLi)在时效过程中的析出。时效过程析出的高密度T_1相可有效钉扎位错,从而使合金的强度及塑性提高;相反,室温轧制+时效工艺得到的合金强度及塑性较低,这是由于低密度的T_1相在晶内析出,而高密度的T_1相在亚晶界处析出。

关 键 词：Al-Cu-Li alloy cryogenic rolling DISLOCATION T1 precipitate 

分 类 号：TG166.3[金属学及工艺—热处理] TG339[金属学及工艺—金属学]