摘要
采用室温拉伸和断裂韧性测试方法,借助扫描电镜、透射电镜等设备,研究时效处理对7050T451铝合金性能的影响及材料微观组织形貌演变。结果表明,160℃时效时,随着时效时间的增加,晶界析出的粗大η相增多,晶界无析出带变宽,7050T451铝合金晶粒内部弥散分布的细小η′相密度增加,成为主要强化相,材料强度提高,延伸率下降;7050T451晶界析出相体积分数随时效时间增加,降低材料断裂韧性;晶粒内残留位错处易析出粗大η相,但数量较少,对材料性能无明显影响。
The effects of aging treatment on mechanical properties and microstructure evolution of 7055T451 aluminum alloy were investigated by fracture toughness test, TEM and SEM observation. The results showed that more precipitates at grain boundary and wider precipitate-free grain boundary were observed. Higher strength and less extensibility were resulted due to the dispersion-strengthening of η phase during aging at 160℃. The volume fraction of grain boundary precipitate increased with increase of aging time, which resulted in the decrease of fracture toughness. A small amount of coarser η phase tended to precipitate at residual dislocation and had no effect on mechanical properties.
出处
《塑性工程学报》
CAS
CSCD
北大核心
2013年第2期116-121,共6页
Journal of Plasticity Engineering
基金
国家自然科学基金资助项目(50975267)
关键词
7050铝合金
时效
显微组织
力学性能
7055 aluminum alloy
aging treatment
microstructure
mechanical properties
