摘要
旨在填补7055铝合金宽温度和宽应变率范围动态冲击的显微组织演变机制的不足,基于较宽温度和应变率范围的霍普金森压杆动态冲击试验,对7055铝合金动态力学性能及动态冲击后试样的SEM和TEM显微组织进行研究,分析温度和动态冲击应变率对7055铝合金组织与性能的影响。结果表明:低温环境下,随着应变率不断增大,7055铝合金的金相组织演变过程均存在绝热剪切带,其内部存在汇聚型微裂纹;随着温度升高,7055铝合金的动态冲击变形组织并未呈明显绝热剪切带,多以扭曲形变带形式存在;温度低于220℃,7055铝合金的TEM显微组织主要以不稳定的η′析出相为主,其数量和密度与温度有明显负相关。
In order to fill the shortcomings of the microstructural evolution mechanism study of the dynamic impact of the wide temperature and the strain rate range of the 7055 aluminum alloy,In this paper,the 7055 aluminum alloy dynamic mechanical properties and microstructures of the samples after dynamic impact were studied based on the wide temperature and strain rate range of the Hopkinson pressure test. The effects of temperature and strain rate on the microstructure and properties of 7055 aluminum alloy were analyzed. The experimental results show that adiabatic shear bands exist in the evolution process of the metallographic structure of 7055 aluminum alloy with the increase of strain rate in low temperature environment,and there are convergent microcracks in the inner part of adiabatic shear zone. With the increase of temperature,the dynamic impact deformation of 7055 aluminum alloy did not show an obvious adiabatic shear zone,mostly in the form of twisted deformation band. The temperature is below 220 ℃,the TEM microstructure of 7055 aluminum alloy mainly unstable precipitated phase η′,the amount of precipitated phase η′ and has obvious negative correlation with density and temperature.
作者
李媛媛
张平
于晓
罗恒
LI Yuanyuan;ZHANG Ping;YU Xiao;LUO Heng(College of Mechanical and Electrical Engineering,Qingdao Huanghai University,Qingdao 266520,China;School of Mechanical and Automotive Engineering,Qingdao University of Technology,Qingdao 266520,China)
出处
《兵器材料科学与工程》
CAS
CSCD
北大核心
2020年第1期20-24,共5页
Ordnance Material Science and Engineering
基金
国家自然科学基金（51705270）
山东省自然科学基金（ZR2016EEP03）
山东省高等学校科技计划项目(J17KA0031
J18KB006)
