铍第1塑性高峰区的流变行为及本构方程
Flow Behavior and Constitutive Equation of Metal Beryllium in the First Plastic Peak Zone
许德美 1李美岁 2李志年 2叶树鹏 3何力军 4李峰2
作者信息
- 1. 北方民族大学材料科学与工程学院粉体材料与特种陶瓷省部共建重点实验室工业废弃物循环利用及先进材料国际科技合作基地,宁夏银川 750021
- 2. 西北稀有金属材料研究院宁夏有限公司稀有金属特种材料国家重点实验室,宁夏石嘴山 753000
- 3. 西北稀有金属材料研究院宁夏有限公司稀有金属特种材料国家重点实验室,宁夏石嘴山 753000;宁夏大学宁夏光伏材料重点实验室,宁夏银川 750021
- 4. 宁夏大学宁夏光伏材料重点实验室,宁夏银川 750021
- 折叠
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10-1～10-4s-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 kJ/mol减少至166.82 kJ/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.
Abstract
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.
关键词
金属铍/第1塑性高峰区/本构方程/变形激活能Key words
metal beryllium/the first plastic peak zone/constitutive equation/deformation activation energy引用本文复制引用
出版年
2024
NETL
NSTL
万方数据