期刊论文详细信息
Journal of Materials Research and Technology
The effect of strain rate asymmetry on the Bauschinger effect: A discrete dislocation plasticity analysis
Gaihuan Yuan1  Mei Zhan2  Daniel S. Balint2  Yudong Lei2  Rui Li2  Zebang Zheng2  Hongrui Zhang3 
[1] Corresponding author.;State Key Laboratory of Solidification Processing, Shaanxi Key Laboratory of High-Performance Precision Forming Technology and Equipment, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, 710072, China;State Nuclear Baoti Zirconium Industry Co., Ltd. (SNZ), Baoji, 721013, China;
关键词: Bauschinger effect;    Discrete dislocation plasticity;    Rate sensitivity;    Thermal activation;    Size effect;   
DOI  :  
来源: DOAJ
【 摘 要 】

A two-dimensional discrete dislocation plasticity model was used to examine the role of strain rate asymmetry on the Bauschinger effect (BE). A simple single crystal single slip plane model was used first to investigate stress–strain response within high strain rate regimes where the rate sensitivity is mainly governed by dislocation nucleation and the free-flight of dislocations. Both the yield strength and the BE of the specimen showed a strong correlation to the forward and reverse deformation rate. Simulations were also carried out on a single crystal with multiple slip systems. The effect of source and obstacle density on the BE and its rate dependence was investigated. We find that the rate dependence of the BE is enhanced by increasing the source density in obstacle-free specimens and is reduced by obstacles when they are present. At low strain rates, where thermally-activated dislocation escape from obstacles becomes the predominant rate-controlling mechanism, the BE of single crystals is only affected by strain rates if the activation energy is low. Grain boundaries in polycrystalline specimens and obstacles with high activation energies act as barriers to dislocation motion, suggesting that the rate dependence under low strain rate regimes is enhanced by decreasing the grain size or reducing the activation energy associated with dislocation escape from obstacles. The effect mechanisms of strain rate asymmetry on the BE can be fundamentally crucial for multiple industrial applications, including lifetime assessments of aero-engine disks, zirconium cladding of nuclear reactor and the spring-back prediction of metal forming.

【 授权许可】

Unknown   

  文献评价指标  
  下载次数:0次 浏览次数:4次