高固溶Al-7Mg合金高温拉伸行为及本构方程研究  

Study on high-temperature tensile deformation behaviors and corresponding constitutive equation of a high solid solution Al-7Mg alloy

作　　者：张洪敏 江鹏[1] 潘海军 闫恪涛 王广原 张彬 ZHANG Hongmin;JIANG Peng;PAN Haijun;YAN Ketao;WANG Guangyuan;ZHANG Bin(School of Mechanical Engineering and Rail Transit,Changzhou University,Changzhou 213164,China)

机构地区：[1]常州大学机械与轨道交通学院,江苏常州213164

出　　处：《常州大学学报(自然科学版)》2025年第1期15-21,共7页Journal of Changzhou University:Natural Science Edition

基　　金：江苏省自然科学基金资助项目(BK20220629);常州大学科学启动基金资助项目(ZMF22020096)。

摘　　要：光学显微镜(OM)及透射电子显微镜(TEM)研究发现热挤压制备的高固溶Al-7Mg合金由均匀粗晶粒组成,平均尺寸约为16μm,基体中没有检测到第二相。通过设计不同变形参数的高温拉伸实验,探索了Al-7Mg合金高温拉伸变形行为。其中,断裂延伸率随温度的升高而提高。较粗的晶粒导致该合金在400℃拉伸时的断裂延伸率约为200%。应变速率敏感系数(0.16~0.31)及变形激活能(124 kJ/mol)计算结果表明随拉伸温度由200℃提高至400℃,Al-7Mg合金的变形机制由位错滑移/蠕变转变为溶质拖拽蠕变,该过程由晶格扩散控制。通过峰值应变处应力值的系统分析,构建了用于预测Al-7Mg合金高温拉伸峰值应力的本构方程。Optical microscopy(OM)and transmission electron microscopy(TEM)results reveal that the Al-7Mg alloy prepared by hot extrusion exhibits a uniform coarse grain structure,with an average size of 16μm.No second phases are detected.Through designing a series of high-temperature tensile experiments with different parameters,the deformation behavior of the Al-7Mg alloy is investigated.The elongation to failure is enhanced with increasing tensile temperature.The coarse grain structure gives rise to elongations to failure of 200%when deformed at 400℃.The calculated results of strain rate sensitivity(0.16~0.31)and deformation activation energy(124 kJ/mol)indicate that the dominant deformation mechanism of Al-7Mg alloy transforms from dislocation slip/creep to solute drag creep with increasing tensile temperature from 200℃to 400℃,which is controlled by lattice diffusion.An Arrhenius-type constitutive model is constructed for predicting peak stress of Al-7Mg,based on systematically analyzing stress at the peak strain.

关 键 词：AL-MG合金 高温拉伸性能 微观组织 本构方程 

分 类 号：TG1[金属学及工艺—金属学]