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.
出处
《材料研究学报》
EI
CAS
CSCD
北大核心
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~~
