Hot Deformation Stability of Extruded AZ61 Magnesium Alloy Using Different Instability Criteria
来源期刊：Acta Metallurgica Sinica2015年第11期
论文作者：Ju-Qiang Li Juan Liu Zhen-Shan Cui
文章页码：1364 - 1372
摘 要：The hot deformation stability of extruded AZ61 magnesium alloy was investigated by means of hot compression tests at the temperature range of 250-400 ℃ and strain rate range of 0.001-1 s-1.The 3D instability maps considering the effect of strain were developed to delineate the regions of unstable flow on the basis of Jonas’ s,Semiatin’s,Prasad’s,Murty’s,Gegel’s and Alexander’s criteria.Since non-uniform deformation occurs due to the initial microstructure inhomogeneity,the friction,etc.,finite element simulations were performed to determine the position of the specimens which can mostly represent the preset deformation parameter.Detailed microstructural investigation on such position was carried out to examine the validity of the instability maps,and the results indicate that for extruded AZ61 magnesium alloy:（1） Jonas’ s and Semiatin’s criteria conservatively predict the instability regions;（2） Gegel’s and Alexander’s criteria inadequately predict the instability regions;（3） Prasad’s and Murty’s criteria provide more effective predictions of the instability regions than Jonas’ s,Semiatin’s,Gegel’s and Alexander’s criteria.
Ju-Qiang Li，Juan Liu，Zhen-Shan Cui
National Engineering Research Center for Die and Mold CAD,School of Materials Science and Engineering,Shanghai Jiao Tong University
摘 要：The hot deformation stability of extruded AZ61 magnesium alloy was investigated by means of hot compression tests at the temperature range of 250-400 ℃ and strain rate range of 0.001-1 s-1.The 3D instability maps considering the effect of strain were developed to delineate the regions of unstable flow on the basis of Jonas’ s,Semiatin’s,Prasad’s,Murty’s,Gegel’s and Alexander’s criteria.Since non-uniform deformation occurs due to the initial microstructure inhomogeneity,the friction,etc.,finite element simulations were performed to determine the position of the specimens which can mostly represent the preset deformation parameter.Detailed microstructural investigation on such position was carried out to examine the validity of the instability maps,and the results indicate that for extruded AZ61 magnesium alloy:（1） Jonas’ s and Semiatin’s criteria conservatively predict the instability regions;（2） Gegel’s and Alexander’s criteria inadequately predict the instability regions;（3） Prasad’s and Murty’s criteria provide more effective predictions of the instability regions than Jonas’ s,Semiatin’s,Gegel’s and Alexander’s criteria.
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