轧制预热时间对01420铝锂合金晶粒细化的影响  

Effect of pre-heating time on grain refinement of 01420 Al-Li alloy

作　　者：叶凌英[1] 张新明[1] 郑大伟[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）》2012年第1期87-92,共6页Journal of Central South University:Science and Technology

基　　金：国际科技合作重点资助项目(2008DFR50260);中南大学自由探索计划资助(2011QNZT004)

摘　　要：采用形变热处理法制备01420铝锂合金细晶板材,研究轧制预热时间对第二相粗化、回溶及最终再结晶组织的影响。研究结果表明:合金在300℃/48 h过时效处理过程中析出大量棒状的微米尺寸S相,这些第二相在随后的轧制前400℃预热过程中不稳定,首先粗化成球形相,当预热时间超过8 h,又开始逐渐地溶解;在400℃预热0～10 h内,第二相分布比较均匀;当预热时间超过12 h,没有溶解的第二相主要分布于晶界处,尺寸较小,是导致最终再结晶组织粗大且呈扁平状的主要原因;随着预热时间的延长,板材轧制和再结晶后的晶粒尺寸逐渐增大,但在预热8 h内增幅较小。板材适宜的轧制预热制度为于400℃预热4～8 h。Fine grained 01420 Al-Li alloy sheet was produced by thermo-mechanical processing.The effects of pre-heating time on precipitate coarsening,dissolution and grain structure were investigated.The results show that a large number of micron-sized,rod-shaped S-phase particles are produced during overaging at 300 ℃ for 48 h.However,these particles are not stable during the following pre-heating at 400 ℃ and they tend to be coarsened to globular particles firstly and then start to dissolve after preheated for more than 8 h.The particles are distributed homogeneously when preheated at 400 ℃ for 0-10 h,but the remained particles are mainly located at grain boundaries when pre-heating duration is over 12 h.This is the main reason of causing the coarse and elongated grain structure.The grain size increases with the increasing preheating time but grows a little in 8 h.The proper pre-heating schedule is at 400 ℃ for 4-8 h.

关 键 词：01420铝锂合金 形变热处理 第二相 粒子激发形核 再结晶 

分 类 号：TG166.3[金属学及工艺—热处理]