Transactions of Materials Processing (소성∙가공)

The Korean Society for Technology of Plasticity and materials processing (한국소성∙가공학회)
권호 표지
DOI QR코드

DOI QR Code

Plastic Deformation and Microstructural Evolution during ECAP Using a Dislocation Cell Related Microstructure-Based Constitutive Model

전위쎌에 기초한 미세조직 구성모델을 이용한 ECAP 공정 시 소성변형과 미세조직의 진화

  • Published : 2006.09.01
Download PDF
⟨ Previous Next ⟩

Abstract

The deformation behavior of copper during equal channel angular pressing(ECAP) was calculated using a three-dimensional version of a constitutive model based on the dislocation density evolution. Finite element simulations of the variation of the dislocation density and the dislocation cell size with the number of ECAP passes are reported. The calculated stress, strain and cell size are compared with the experimental data for Cu deformed by ECAP in a modified Route C regime. The results of FEM analysis were found to be in good agreement with the experiments. After a rapid initial decrease down to about 200nm in the first ECAP pass, the average cell size was found to change little with further passes. Similarly, the strength increased steeply after the first pass, but tended to saturate with further pressings. The FEM simulations also showed strain non-uniformities and the dependence of the resulting strength on the location within the workpiece.

Keywords

References

  1. V. M. Segal, 1996, Materials Processing by Simple Shear, Mater. Sci. Eng., Vol. A197, pp. 157-164
  2. R. Z. Valiev, 2001, Developing SPD Methods for Processing Bulk Nanostructured Materials with Enhanced Properties, Metal. Mater. Inter., Vol. 7, pp. 413-420
  3. L. S. Toth, A. Molinari, Y. Estrin, 2002, Strain Hardening at Large Strains as Predicted by Dislocation Based Polycrystal Plasticity Model, J. Eng. Mater. Technol., Vol. 124, pp. 71-77 https://doi.org/10.1115/1.1421350
  4. M. Muller, M. Zehetbauer, A. Borbely, T. Ungar, 1996, Stage IV Work Hardening in Cell Forming Materials, Part I: Features of the Dislocation Structure Determined by X-Ray Line Broadening, Scripta Mater., Vol. 35, pp. 1461-1466 https://doi.org/10.1016/S1359-6462(96)00319-3
  5. ABAQUS/Standard, Version 6.4
  6. S. C. Baik, R. Hellmig, Y. Estrin, H. S. Kim, 2003, Modeling of Deformation Behavior of Copper under ECAP, Z. Metallk., Vol. 94, pp. 754-760 https://doi.org/10.3139/146.030754
  7. H. S. Kim, M. H. Seo, S. I. Hong, 2000, On the Corner Gap in the Equal Channel Angular Pressing, Mater. Sci. Eng., Vol. 291 A, pp. 86-90 https://doi.org/10.1016/S0921-5093(00)00970-9
  8. H. S. Kim, S. I. Hong, M. H. Seo, 2001, Effects of Strain Hardenability and Strain Rate Sensitivity on the Plastic Flow and Deformation Homogeneity during ECAP, J. Mater. Res., Vol. 16, pp. 856-864 https://doi.org/10.1557/JMR.2001.0113