7075铝合金多场耦合流变行为和软化机理  

Multi-field coupled rheological behavior and softening mechanism of 7075 aluminum alloy

作　　者：朱春雨 夏建生[1,2] 窦沙沙 刘镕滔[1] 钱海旭 朱云飞 ZHU Chun-yu;XIA Jian-sheng;DOU Sha-sha;LIU Rong-tao;QIAN Hai-xu;ZHU Yun-fei(Mechanical Engineering College,Yancheng Institute of Technology,Yancheng 224001,China;School of Mechanical Engineering,Yanshan University,Qinhuangdao 066004,China)

机构地区：[1]盐城工学院机械工程学院,江苏盐城224001 [2]燕山大学机械工程学院,河北秦皇岛066004

出　　处：《塑性工程学报》2024年第5期113-123,共11页Journal of Plasticity Engineering

基　　金：国家自然科学基金资助项目(51505408)。

摘　　要：在应变速率为0.01~10 s^(-1),电流密度为18~27 A·mm^(-2),温度为150~330℃条件下,对7075铝合金进行了脉冲电流辅助拉伸实验。探讨了应变速率与电流密度对7075铝合金力学性能的影响,推导出耦合了电参数的修正Johnson-Cook本构模型,并进行了验证。为解析热、电与力的耦合关系提供了新的研究思路。结果表明,与室温相比,通电试样的断面形貌中出现尺寸更大、分布更规整的韧窝。应变速率0.1~1 s^(-1)和电流密度21~24 A·mm^(-2)对降低7075铝合金的流动应力有着显著影响,说明电流密度的影响存在阈值。并且修正后的Johnson-Cook模型在预测上展现出了较高的可靠性,模型预测与试验数据高度吻合,相关性达到0.9961,平均绝对相对误差仅为3.35%。Pulse current-assisted tensile experiments of 7075 aluminum alloy were carried out under the condition of strain rate of 0.01-10 s^(-1),current density of 18-27 A·mm^(-2) and temperature of 150-330℃.The effects of strain rate and current density on the mechanical properties of 7075 aluminum alloy were explored,and the modified Johnson-Cook constitutive model coupled with electrical parameters was derived and validated.New research ideas were provided for analyzing the coupling relationship among heat,electricity and force.The results show that compared with room temperature,well-distributed dimples with larger size appear in cross-section morphology of the energized sample,and strain rate of 0.1-1 s^(-1) and current density of 21-24 A·mm^(-2) have significant effects on the reduction of the flow stress of 7075 aluminum alloy,which indicates that there is a threshold value for the effect of current density.And the modified Johnson-Cook model shows high reliability in prediction,and the model prediction is in high agreement with the experimental data,with correlation of 0.9961,and the average relative error is only 3.35%.

关 键 词：7075铝合金 电塑性效应 多场耦合 Johnson-Cook本构模型 

分 类 号：TG306[金属学及工艺—金属压力加工]