预变形对AA2195铝锂合金析出及晶粒细化的影响  

Effects of pre-deformation on precipitating behavior and grain refinement of AA2195 Al-Li alloy

作　　者：张新明[1] 刘颖维[1] 叶凌英[1] 唐建国[1] 

机构地区：[1]中南大学材料科学与工程学院,湖南长沙410083

出　　处：《中南大学学报（自然科学版）》2009年第2期375-382,共8页Journal of Central South University:Science and Technology

基　　金：国际科技合作重点资助项目(2006DFA53250);国家重点基础研究发展计划项目(2005CB623706)

摘　　要：在细化晶粒的传统机械热处理工艺中的过时效前引入冷轧预变形,研究预变形对AA2195铝锂合金过时效第二相粒子组态及最终再结晶组织的影响。结果表明:预变形明显降低了过时效第二相沿板材厚度方向分布的不均匀性,并大大减小长度为5～10μm的棒状第二相,显著增加尺寸为0.8～2.0μm的第二相,从而提高再结晶时的形核核心。与未采用预变形的板材相比,经60%预变形的板材经轧制和再结晶后表层的晶粒尺寸由未预变形的12.6μm减小至9.26μm,其纵横比由1.61减小至1.27;中心层晶粒尺寸由14.62μm减小至11.27μm,其纵横比由2.47减小至1.70。过时效前的轧制预变形明显细化并等轴化AA2195铝锂合金的晶粒。In order to investigate the effects of the pre-deformation on second phase particles and recrystallization of AA2195 Al-Li alloy, cold-rolling pre-deformation prior to overaging was exploited in the traditional thermo-mechanical processing for grain refinement. The results show that the pre-deformation reduces the non-uniform distribution of the second phase particles along thickness of the plate, decreases the large rod particles with length of 5-10 lira and increases the particles with diameter of 0.8-2.0μm dramatically, which results in increasing nucleation sites of recrystallization. In comparison with the sheet without pre-deformation, subsequent rolling and recrystallization decrease the final grain size and grain aspect ratio from 12.6 p.m and 1.61 to 9.26μm and 1.27 in the surface layer, and decrease the grain size and grain aspect ratio in the center layer from 14.62μm and 2.47 to 11.27μm and 1.70. Pre-deformation prior to overaging remarkably refine and spheroidize the grain structure of AA2195 Al-Li alloy.

关 键 词：AA2195铝锂合金 预变形 第二相粒子 粒子激发形核 机械热处理 

分 类 号：TG166.3[金属学及工艺—热处理]