7050铝合金在不同温度变形的动态析出行为  

Dynamic Precipitation of 7050 Al Alloy on the Different Deformation Temperature

作　　者：郎玉婧[1] 崔华[2] 蔡元华[1] 张济山[1] 

机构地区：[1]北京科技大学新金属材料国家重点实验室,北京100083 [2]北京科技大学材料科学与工程学院,北京100083

出　　处：《材料研究学报》2012年第2期143-148,共6页Chinese Journal of Materials Research

基　　金：新金属材料国家重点实验室自主课题2008Z-13资助项目~~

摘　　要：研究了7050铝合金在不同温度变形的动态析出行为,结果表明:7050铝合金在不同温度的变形过程中MgZn2相动态析出不影响流变应力的波动,变形加速了动态析出过程;随着变形温度的升高,部分析出相MgZn_2颗粒由球状变成板条状,尺寸增大数量减少,在450℃变形过程中粗大的板条状MgZn_2相易破碎;同时,位错密度减低,位错胞团变成离散位错墙。析出相钉扎位错和阻碍晶界迁移,主要以亚稳态η′和平衡态η形式存在,在变形过程中不会产生微裂纹。Dynamic precipitation of 7050 AI alloy on the different deformation temperature was investigated. The results show that dynamic precipitation of MgZn2 phases can not affect the jagged fluctuations of the true stress-strain curves, and the deformation accelerated the dynamic precipitation. With increasing of deformation temperature, partial spherical precipitates become to rod-like precipitates, and the size of the precipitates increased while the quantity reduced. Large rod-like MgZn2 precipitates are fragmented during the deformation at 450℃. Simultaneity, the density of the dislocation also decreased, and the dislocation cells transform into the discrete dislocation. The precipitates pin the dislocations and prevent the grain boundary impingement. The precipitates have mainly the metastable r/~ phase and equilibrium 77 phase, and can not induce the micro-crack.

关 键 词：金属材料 7050铝合金 热变形 动态析出 MgZn2相 

分 类 号：TG146[一般工业技术—材料科学与工程] TG111[金属学及工艺—金属材料]