摘要
采用电子背散射衍射技术,研究了分别使用两种铝合金(3102和3F03)制备的同规格微通道扁管的晶粒组织,比较了5%冷轧变形后两种铝扁管中的残余应变分布。对冷轧后的铝扁管进行600℃/3 min退火处理,获得了包含异常大晶粒的退火组织。基于铝扁管的单向拉伸实验数据和加工硬化率曲线,建立了含应变修正项的硬化模型。使用该模型对单向拉伸变形过程中铝扁管材料中的位错密度和位错平均自由程演化进行了求解。结果表明:相比于3F03挤压态铝扁管,5%冷轧变形使得3102挤压态铝扁管筋部组织发生较高程度加工硬化;3102挤压态铝扁管在塑性变形过程中的位错平均自由程较小;3102挤压态铝扁管因具有较高的Si元素固溶含量和较小的晶粒尺寸而具有较高的加工硬化率。
The grain structures of the micro-channel flat tubes of the same profile extruded from 3102 and 3F03 aluminum alloys were investigated by electron backscatter diffraction(EBSD),respectively.The distribution of the residual strain in the two alloy tubes with 5%cold rolling reduction was compared.The cold rolled tubes were annealed under 600℃for 3 min and the microstructures with abnormally large grains were obtained.The hardening model with strain correction term was established based on the data of uniaxial tensile test of the aluminum alloy flat tube and the work hardening rate curve.The dislocation density and the mean free path evolution of dislocation in the aluminum alloy flat tube material during the uniaxial tensile tests were calculated by the established model.The result shows that the 5%cold rolling reduction produces stronger work hardening in the web of as-extruded 3102 aluminum alloy flat tube than in the as-extruded 3F03 aluminum alloy flat tube.The as-extruded 3102 aluminum alloy flat tube has lower mean free path of dislocation during the plastic deformation.For higher Si content of solid solution and lower grain size in as-extruded 3102 aluminum alloy flat tube,the higher work hardening rate is obtained.
作者
李凯
邹天下
李大永
彭颖红
唐鼎
LI Kai;ZOU Tian-xia;LI Da-yong;PENG Ying-hong;TANG Ding(School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)
出处
《塑性工程学报》
CAS
CSCD
北大核心
2020年第4期110-117,共8页
Journal of Plasticity Engineering
基金
国家自然科学基金资助项目(51705315)。
关键词
铝合金
微通道扁管
晶粒组织
加工硬化率
位错密度
aluminum alloy
micro-channel flat tube
grain structure
work hardening rate
dislocation density
