工程科学学报2017，Vol.39Issue(6)：875-881,7.DOI:10.13374/j.issn2095-9389.2017.06.009
冷却速度对圆形加载路径下A319铝合金多轴疲劳特性的影响
Effects of cooling velocity on multiaxial fatigue behavior of A319 alloy under circular loading conditions
摘要
Abstract
The effects of cooling velocity on the multiaxial fatigue properties of A319 alloy under circular loading conditions was studied by using the MTS809 servo-hydraulic testing system and scanning electron microscopy. The results indicate that the solidifica-tion cooling velocity of 10℃·s-1 leads to decrease in the size of microstructures, such as second dendrite arming space, Si particle, and void compared. Hysteresis loops with smaller second dendrite arming space show that there is almost no phase angle between strain and stress along the axial direction. Furthermore, the decrease in second dendrite arming space size manifests as a more remarkable additional hardening effect compared to that of the sample with a cooling velocity of 0. 1℃·s-1 . The local regions of crack initiation are completely different. The cracks in samples solidified at a cooling velocity of 10℃·s-1 initiate and propagate from large Si particu-lars, in contrast to the cracks in samples solidified at a cooling velocity of 0. 1℃·s-1 , which initiate from pores. It is also found the A319 samples under the two different cooling velocities show initial cyclic hardening followed by cyclic softening in the axial direction and initial cyclic hardening followed by stable tendency in the shear direction.关键词
A319铝合金/冷却速度/圆形路径/二次枝晶臂间距Key words
A319 aluminum alloy/cooling velocity/circular loading/second dendrite arming space分类
矿业与冶金引用本文复制引用
戴礼权,何国球,叶赟,吕世泉,刘晓山,王其桂..冷却速度对圆形加载路径下A319铝合金多轴疲劳特性的影响[J].工程科学学报,2017,39(6):875-881,7.基金项目
美国通用汽车公司资助项目(1314) （1314）
东北大学轧制技术及连轧自动化国家重点实验室开放课题基金资助项目(2016008) （2016008）
