含铒铝合金显微组织对疲劳裂纹扩展的影响  

Effect of Microstructure on Fatigue Crack Propagation of Er-containing Aluminum Alloy

作　　者：雷欣[1] 聂祚仁[1] 黄晖[1] 

机构地区：[1]北京工业大学,北京100124

出　　处：《稀有金属材料与工程》2016年第4期1035-1039,共5页Rare Metal Materials and Engineering

基　　金：国家"973"计划(2012CB619503)

摘　　要：对含铒铝合金板材进行了不同的热处理,分析了各板材的显微组织对疲劳裂纹扩展和力学性能的影响。结果表明:晶粒的长/径比越小,板材的疲劳裂纹扩展速率越慢;且随着疲劳裂纹扩展速率的降低,裂纹宽度增加且裂纹路径曲折;稀土元素Er的加入,在合金中形成Al_3(Er,Zr)第二相粒子,其强烈地钉扎位错,阻碍位错运动,以减少位错在晶界处的聚集产生的应力集中,降低板材的疲劳裂纹扩展速率。Er-containing Al-Mg alloy plates were processed by different heating treatments. The effects of microstructure on fatigue crack propagation of the plates were analyzed. The results show that the smaller the length/diameter ratio of the grain, the slower the fatigue crack propagation rate; with the reduction of fatigue crack propagation rate, the crack width increases, while the crack path twists and turns. Due to the addition of rare earth element Er, Al3（Er, Zr） particles are formed in the alloy, and they pin the dislocation strongly, hinder dislocation motion, and reduce the stress concentration in the grain boundary produced by the dislocation pile-up, thus reducing the fatigue crack growth rate.

关 键 词：疲劳裂纹扩展 铒 铝合金 

分 类 号：TG146.21[一般工业技术—材料科学与工程]