福州大学 机械工程及自动化学院， 福州 350116
出版日期:2018-05-28发布日期:2018-05-28基金资助:国家科技重大专项(2013ZX04009),国家自然科学基金项目(51375094)Oxygen Free Copper Dynamic Mechanical Property in High Speed Machining Process
YU Jianchao,LIN YouxiSchool of Mechanical Engineering and Automation, Fuzhou University, Fuzhou 350116, China
Online:2018-05-28Published:2018-05-28摘要/Abstract
摘要： 通过对高速加工中无氧铜工件材料在温度为20~900℃，应变率为1.0×103~1.5×104s-1的条件下，进行霍普金森压杆试验，获得反映材料动态力学性能的真应力-真应变曲线.结果表明：无氧铜的力学性能表现出对应变率和温度的敏感性较强，其流动应力随着应变率的提高而显著增加，而且变形温度的升高使得流动应力明显下降；采用经验型Johnson-Cook本构模型预测无氧铜的动态力学性能的误差较大；在动态力学性能分析的基础上，采用修正的Johnson-Cook本构模型能够较好地预测试验结果，可用于高速加工中无氧铜的动态力学性能模拟分析.
关键词: 无氧铜, 高速加工, 动态力学性能, 本构模型
Abstract: Hopkinson pressure bar experiments of oxygen free copper in high speed machining process were carried out with temperature ranging from 20℃ to 900℃ and strain rate ranging from 1.0×103 to 1.5×104s-1. The true stress-true strain curves obtained from experiments showed that the mechanical property of oxygen free copper showed obvious strain rate and temperature sensitivity. The flow stress increased significantly with the increase of strain rate and decreased with the increase of deformed temperature. The empirical Johnson-Cook constitutive model had a large error in describing the dynamic mechanical property. Based on the analysis of dynamic mechanical property, a modified Johnson-Cook constitutive model was proposed. It can predicte experimental results well, and then can be used to simulate dynamic mechanical property of oxygen free copper in high speed machining process.
Key words: oxygen free copper, high speed machining, dynamic mechanical property, constitutive model
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