Influence of strain gradients on the grain refinement during industrial scale ECAP

Frint, P.; Hockauf, M.; Dietrich, D.; Halle, T.; Wagner, M.F.-X.; Lampke, T.

doi:10.1002/mawe.201100839

Influence of strain gradients on the grain refinement during industrial scale ECAP (bibtex)

by P. Frint, M. Hockauf, D. Dietrich, T. Halle, M.F.-X. Wagner, T. Lampke

Abstract:

The microstructure of the aluminium alloy 6060 after industrial scale (cross-section 50×50 mm²) equal-channel angular pressing (ECAP) is studied. We focus on processing without additional backpressure in order to allow the formation of a corner gap and the corresponding development of a distinct strain gradient after one pass. Low voltage scanning transmission electron microscopy (STEM) and electron backscatter diffraction analysis (EBSD) are used to determine the average grain size, grain boundary misorientation angles and grain shape aspect ratios. These microstructural parameters are analysed for three characteristic locations from top to bottom within the billet. Our EBSD observations clearly document the occurrence of global strain gradients and microstructural heterogeneity. The STEM analyses expand the information on this heterogeneous deformation for the investigated locations in the sub-micrometer range. In good agreement with previous studies, our results provide detailed information on how a heterogeneous induced shear strain affects microstructure and mechanical properties when ECAP is performed without backpressure.

Reference:

Frint, P., Hockauf, M., Dietrich, D., Halle, T., Wagner, M.F.-X., Lampke, T.: Influence of strain gradients on the grain refinement during industrial scale ECAP, Materialwissenschaft und Werkstofftechnik 42, 680-685, 2011.

Bibtex Entry:

@Article{Frint2011a,
  author    = {Frint, P. and Hockauf, M. and Dietrich, D. and Halle, T. and Wagner, M.F.-X. and Lampke, T.},
  journal   = {Materialwissenschaft und Werkstofftechnik},
  title     = {{Influence of strain gradients on the grain refinement during industrial scale {ECAP}}},
  year      = {2011},
  month     = jul,
  number    = {7},
  pages     = {680--685},
  volume    = {42},
  abstract  = {The microstructure of the aluminium alloy 6060 after industrial scale (cross-section 50×50 mm\textsuperscript{2}) equal-channel angular pressing (ECAP) is studied. We focus on processing without additional backpressure in order to allow the formation of a corner gap and the corresponding development of a distinct strain gradient after one pass. Low voltage scanning transmission electron microscopy (STEM) and electron backscatter diffraction analysis (EBSD) are used to determine the average grain size, grain boundary misorientation angles and grain shape aspect ratios. These microstructural parameters are analysed for three characteristic locations from top to bottom within the billet. Our EBSD observations clearly document the occurrence of global strain gradients and microstructural heterogeneity. The STEM analyses expand the information on this heterogeneous deformation for the investigated locations in the sub-micrometer range. In good agreement with previous studies, our results provide detailed information on how a heterogeneous induced shear strain affects microstructure and mechanical properties when ECAP is performed without backpressure.},
  doi       = {10.1002/mawe.201100839},
  keywords  = {Aluminium alloy, EBSD, Equal-channel angular pressing (ECAP), Grain size, STEM},
  publisher = {Wiley-Blackwell},
}