7150⁃T6铝合金动态特性实验及本构方程研究  

Experimental Study of Dynamic Characteristics and Constitutive Equation of 7150⁃T6 Aluminum Alloy

作　　者：陈睿[1,2] 温仕成[1,2] 王旭 彭锐涛[1,2] 胡聪芳[1,2] CHEN Rui;WEN Shicheng;WANG Xu;PENG Ruitao;HU Congfang(School of Mechanical Engineering,Xiangtan University,Xiangtan 411105,Hu′nan,China;Engineering Research Center of Complex Track Processing Technology and Equipment,Ministry of Education,Xiangtan University,Xiangtan 411105,Hu′nan,China)

机构地区：[1]湘潭大学机械工程学院,湖南湘潭411105 [2]湘潭大学复杂轨迹加工工艺及装备教育部工程研究中心,湖南湘潭411105

出　　处：《机械科学与技术》2022年第8期1270-1277,共8页Mechanical Science and Technology for Aerospace Engineering

基　　金：国家自然科学基金项目(11602212,51975504,51705442);湖南省杰出青年项目(2022JJ10045);湖南省自然科学基金项目(2018JJ3509);湖南省教育厅一般项目(19C1785)。

摘　　要：为研究高温与高应变率对7150⁃T6铝合金动态力学性能的影响,利用分离式霍普金森压杆装置进行动态冲击试验,并对冲击后试样进行了SEM显微组织分析。结果表明:7150⁃T6铝合金在常温、高应变率下呈现局部热软化现象和较弱的应变率敏感性。材料的流动应力随着温度的升高而不断减小,尤其当温度高于200℃时,流动应力显著降低。在高应变率冲击下,应变率增大使绝热剪切带的形成更加明显,而高温下未发生明显绝热剪切现象。通过最小二乘法拟合出的Johnson⁃Cook本构方程能够有效预测不同加载条件下的流动应力,其预测结果与试验结果基本吻合。本研究可为7150⁃T6铝合金在汽车等运载器结构的轻量化与安全性设计提供指导。In order to investigate the effect of high temperature and high strain rate on the dynamic mechanical properties of 7150⁃T6 aluminum alloy,the dynamic impact experiments are carried out by split Hopkinson pressure bar(SHPB),and the microstructure of samples are observed by scanning electron microscopy(SEM).The results show that 7150⁃T6 aluminum alloy has local thermal softening and weak strain rate sensitivity under high strain rate at room temperature.The flow stress of the material decreases with the increasing of temperature.Especially as the temperature above 200℃,the flow stress decreases significantly.Under high strain rate,the higher strain rate causes more obvious adiabatic shear band,while the phenomenon does not occur at high temperature.The Johnson⁃Cook constitutive equation fitted by the least square method can effectively predict the flow stress under different loading conditions,and the results are well consistent with the experiment data.The research can provide guidance for the lightweight and safety design of 7150⁃T6 aluminum alloy in vehicles.

关 键 词：7150⁃T6铝合金 SHPB实验 高温 高应变率 Johnson⁃Cook本构模型 绝热剪切带 

分 类 号：TH212[机械工程—机械制造及自动化] TH213.3