'Periodica Polytechnica Budapest University of Technology and Economics'
Abstract
Equal-Channel Angular Pressing (ECAP) is an effective
tool for producing
ultra fine grained materials. In repeated application of ECAP, the rotation
of the sample along the longitudinal axis of the billet allows to
carry out different routes of deformation. The applied route has a strong
influence on the texture, microstructure and mechanical behaviour of ECAP
processed metals. In the present study ECAP was successfully applied to
produce ultra fine-grained microstructure in a commercial Al-Mg-Si alloy (Al
6082). The mechanical investigations of the ECAP deformed specimens revealed
that after 4 ECAP passes the material had a very high strength but
a significantly decreased ductility. Further ECAP processing to 8 passes by
route C increased ductility dramatically and
strength slightly. The diameter ratio of the ellipse shaped cross-section of
the
compressed specimens was the highest for the sample deformed by route C for
eight passes. This indicates that the anisotropy of the structure of ECAP
deformed materials may play an important role in achieving good ductility.
The quality of the ultra-precision finished surface of the processed sample
improved dramatically after eight passes