Application of the Mechanical Threshold Stress Model to Large Strain Processing  

作　　者：Paul S. Follansbee Paul S. Follansbee(Professor Emeritus, Saint Vincent College, Latrobe, PA, USA)

机构地区：[1]Professor Emeritus, Saint Vincent College, Latrobe, PA, USA

出　　处：《Materials Sciences and Applications》2022年第5期300-316,共17页材料科学与应用期刊（英文）

摘　　要：Large-strain deformations introduce several confounding factors that affect the application of the Mechanical Threshold Stress model. These include the decrease with the increasing stress of the normalized activation energy characterizing deformation kinetics, the tendency toward Stage IV hardening at high strains, and the influence of crystallographic texture. Minor additions to the Mechanical Threshold Stress model are introduced to account for variations of the activation energy and the addition of Stage IV hardening. Crystallographic texture cannot be modeled using an isotropic formulation, but some common trends when analyzing predominantly shear deformation followed by uniaxial deformation are described. Comparisons of model predictions with measurements in copper processed using Equal Channel Angular Pressing are described.Large-strain deformations introduce several confounding factors that affect the application of the Mechanical Threshold Stress model. These include the decrease with the increasing stress of the normalized activation energy characterizing deformation kinetics, the tendency toward Stage IV hardening at high strains, and the influence of crystallographic texture. Minor additions to the Mechanical Threshold Stress model are introduced to account for variations of the activation energy and the addition of Stage IV hardening. Crystallographic texture cannot be modeled using an isotropic formulation, but some common trends when analyzing predominantly shear deformation followed by uniaxial deformation are described. Comparisons of model predictions with measurements in copper processed using Equal Channel Angular Pressing are described.

关 键 词：Mechanical Threshold Stress Model Large-Strain Deformations ECAP Stress-Strain Curves Shear Deformations Activation Energy STRAIN-HARDENING 

分 类 号：TG1[金属学及工艺—金属学]