Al-17.5Si-4Cu-0.5Mg合金在热压缩变形中的流变应力行为  

Flow stress behaviour of Al-17.5Si-4Cu-0.5Mg alloy under hot compression deformation

作　　者：李润霞[1] 张立军[1] 刘兰吉[1] 张磊[1] 白彦华[1] 李荣德[1] 

机构地区：[1]沈阳工业大学材料学院,沈阳110870

出　　处：《塑性工程学报》2015年第4期133-140,共8页Journal of Plasticity Engineering

基　　金：国家自然科学基金资助项目(50971092);辽宁省自然科学基金资助项目(201202166);沈阳市人才资源开发专项基金资助项目(201327013)

摘　　要：采用Gleebe-1500D热压缩模拟试验机在变形温度350℃~500℃、应变速率0.001s-1~5s-1的条件下对Al-17.5Si-4Cu-0.5Mg合金进行热压缩实验,研究该合金在热塑性变形条件下的流变应力行为,并建立热变形时的本构方程。研究结果表明,随着应变速率的增加、变形温度的降低,合金的流变应力增加,为正应变速率敏感性材料;采用Znenr-Hollomon参数双曲正弦形式对合金高温塑性变形时的流变应力行为进行描述,流变应力σ解析表达式中材料常数A,σ,n分别为1.81×1019s-1,0.024MPa-1和6.37,合金的平均热变形激活能Q为308.61kJ·mol-1。Hot-compression tests of Al-17.5Si-4Cu-0. 5Mg alloy were carried out at 350℃-500℃ and strain rates of 0. 001 S-1- 5 s-1 on a hot-simulation machine Gleeble-1500D. The flow stress behaviors of the alloy in the hot plastic deformation were stud- ied, and the constitutive equation of the alloy during hot deformation was established. The results showed that： the flow stress increases with rising of the strain rate and decreasing of the deformation temperature; the alloy fracture phenomenon appeared when the strain rate exceeds 1 s-1 , which indicates that this alloy is not suitable for hot processing at high strain rate; the Znenr- Hollomon hyperbolic sine form is available to describe the flow stress during high temperature deformation behavior of the alloy; the average thermal activation energy Q is calculated as 308.61kJ mol-1.

关 键 词：AL-SI-CU-MG合金 热压缩变形 流变应力 本构方程 

分 类 号：TG146.2[一般工业技术—材料科学与工程]