Mg-6.5Y-2.5Nd-0.6Zr合金热压缩变形流变应力行为  

Flow stress behavior of Mg-6.5Y-2.5Nd-0.6Zr alloy during hot compression deformation

作　　者：李伟 高家诚[1,2] 

机构地区：[1]国家镁合金材料工程技术研究中心,重庆400044 [2]重庆大学材料科学与工程学院,重庆400045

出　　处：《材料热处理学报》2011年第3期40-46,共7页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(30670562)

摘　　要：在变形温度为623～773 K、应变速率为0.01～1.0 s-1、最大变形量为60%条件下,采用Gleeble-1500D热/力模拟机对Mg-6.5Y-2.5Nd-0.6Zr合金热压缩变形流变应力行为进行实验研究。结果表明:在应变速率为1.0 s-1等温压缩时,由变形热引起的温升最大达到25 K,修正后流变应力最大比测量值增加31.2 MPa;而应变速率为0.1 s-1压缩时,流变应力的修正值较测量值先减小后增大,其差值在7.8 MPa以内。根据修正的真应力-真应变曲线,结合包含双曲正弦形式的Arrhenius方程并引入Zener-Hollomon参数建立了流变应力本构方程,运用该方程计算的峰值应力与修正的实验数据吻合很好,其相对误差不超过5%。The flow stress behavior of Mg-6.5Y-2.5Nd-0.6Zr alloy was studied during hot compression deformation on a Gleeble-1500 thermal-mechanical simulator at 623-773 K,strain rates from 0.01 to 1.0 s-1 and maximum deformation of 60%.The results show that the maximum temperature rising induced by deformation heat is 25 K during isothermal compression in strain rate of 1.0 s-1,and the corrected flow stress is 31.2 MPa higher than the measured value.The corrected flow stress decreases first then increases compared with the measured values during hot compression in strain rate of 0.1 s-1,and their difference is less than 7.8 MPa.A flow stress constitutive equation was constituted based on Arrhenius equation containing hyperbolic sine function and Zener-Hollomon parameter.Using the constitutive equation,the calculated peak stresses agree well with the corrected experimental stress values under the experimental condition,and their relative error is not more than 5%.

关 键 词：稀土镁合金 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]