摘要
利用Instron 5582万能材料试验机进行等温压缩试验,获得金属铍在变形温度为250~450℃、应变速率为10^(-1)~10^(-4)s^(-1)条件下的真应力-应变曲线,研究金属铍第1塑性高峰区的流变行为。结果表明:实验条件下,金属铍流变应力随应变速率的增大而增大,随变形温度的升高而减小,具有较大的温度敏感性。各变形条件下,金属铍真应力-应变曲线表现为动态回复曲线特征,压缩后样品晶粒伸长,为典型的压力加工组织,这些研究结果表明动态回复是金属铍第1塑性高峰区变形时的主要软化机制。随着应变量的增加,金属铍的变形激活能从244.95 k J/mol减少至166.82 k J/mol。建立了包含应变量的Arrhenius应变补偿本构方程,预测相对误差(MRE)最大为5.0550%,相关系数(R)最小为0.9899,能够较准确预测金属铍在第1塑性高峰区压缩变形时的流变应力。
The true stress-true strain curves of the metal beryllium were obtained under deformation temperature of 250-450℃and strain rate of 10^(-1)~10^(-4)s^(-1)by the isothermal compression testing which was conducted on the Instron 5582 universal material testing machine,and thus flow behavior of the metal beryllium was studied in the first plastic peak zone.The results indicate that the flow stress of the metal beryllium increases with the increase in strain rate and decreases with the increase in deformation temperature under the experimental conditions.Furthermore,the flow stress is more sensitive to the variation of temperature.Under various deformation conditions,the true stress-true strain curves of the metal beryllium show the characteristic of dynamic recovery curve.Moreover,the compressed samples exhibit a typical pressure-working microstructure with elongated grains.These results indicate that dynamic recovery is the main softening mechanism of the metal beryllium during deformation in the first plastic peak zone.The deformation activation energy of the metal beryllium decreases from 244.95 kJ/mol to 166.82 kJ/mol as the strain increase.An Arrhenius strain compensated constitutive equation including strain variables was established.The equation can accurately predict the flow stress of the metal beryllium during compression deformation in the first plastic peak zone,and the maximum mean relative estimation error(MRE)is 5.0550%,and the minimum correlation coefficient(R)is 0.9899.
作者
许德美
李美岁
李志年
叶树鹏
何力军
李峰
Xu Demei;Li Meisui;Li Zhinian;Ye Shupeng;He Lijun;Li Feng(International Scientific&Technological Cooperation Base of Industrial Waste Recycling and Advanced Materials,Key LaboratoryofPowder Material&Advanced Ceramics,School of Materials Science and Engineering,North Minzu University,Yinchuan 750021,China;State Key Laboratory for Special Rare Metal Materials,Northwest Rare Metal Materials Research Institute Ningxia Co.,Ltd,Shizuishan 753000,China;Ningxia Key Laboratory of Photovoltaic Materials,Ningxia University,Yinchuan 750021,China)
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2024年第12期3413-3421,共9页
Rare Metal Materials and Engineering
基金
国家自然科学基金(51874246)。
关键词
金属铍
第1塑性高峰区
本构方程
变形激活能
metal beryllium
the first plastic peak zone
constitutive equation
deformation activation energy
