摘要
在热冲压过程中,AA7075高强铝合金板料经充分固溶后移入室温模具进行冲压成形并淬火。为表征AA7075铝合金在热冲压工艺中的变形行为,在温度200~480℃、应变速率0.01~10s-1范围内进行了高温拉伸试验。基于Arrhenius类型本构模型、Johnson-Cook模型以及Zerilli-Armstrong模型提出了多种修正本构模型,并应用实验所获流变曲线进行了拟合。提出的修正模型通过将模型参数表示为应变、应变速率及温度相关的多项式函数耦合了应变、应变速率及温度对流变应力的影响,并通过均方误差(MSE)以及相关系数R值对模型流变应力预测准确性进行了评价。结果表明,修正的Johnson-Cook模型能够更加准确的预测AA7075高温流变行为。
In hot stamping,the high strength aluminum alloy AA7075 blank was first fully solutionized and then transferred into room temperature tools for stamping and quenching.To characterize the AA7075 alloy hot deformation behavior,tensile tests employing the heating path representative of the hot stamping process were performed over a temperature range of 200~480°C and a strain rate range of 0.01~10 s-1.Modified constitutive models based on the Arrhenius type model,Johnson-Cook model and Zerilli-Armstrong model were proposed and calibrated using the hot tensile test data.The proposed models coupled the effects of strain,strain rate and temperature on flow stress by expressing the model parameters as polynomial functions of strain,strain rate and temperature.The prediction accuracy of the constitutive models for flow stress was evaluated by the mean square error(MSE)and the correlation coefficient R value.The results indicate that the modified Johnson-Cook model can provide the most accurate prediction for the AA7075 hot flow behavior.
作者
王宁
Andrey Ilinich
陈明和
George Lucky
Guillaume D’Amours
Wang Ning;Andrey Ilinich;Chen Minghe;George Lucky;Guillaume D’Amours(Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China;Ford Motor Company,Dearborn MI-48124,USA;National Research Council of Canada,Chicoutimi G7H 8C3,Canada)
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2020年第1期10-20,共11页
Rare Metal Materials and Engineering
