Effect of Severe Plastic Deformation on Structure and Properties of Al-Sc-Ta and Al-Sc-Ti Alloys.
The comparative analysis of the effect of monotonous and non-monotonous severe plastic deformations (SPD) on the structure and properties of aluminum alloys has been carried out. Conventional hydrostatic extrusion (HE) with a constant deformation direction and equal-channel angular hydroextrusion (ECAH) with an abrupt change in the deformation direction were chosen for the cases of monotonous and non-monotonous SPD, respectively. Model cast hypoeutectic Al-0.3%Sc alloys and hypereutectic Al-0.6%Sc alloys with Ta and Ti additives were chosen for studying. It was demonstrated that SPD of the alloys resulted in the segregation of the material into active and inactive zones which formed a banded structure. The active zones were shown to be bands of localized plastic deformation. The distance between zones was found to be independent of the accumulated strain degree and was in the range of 0.6-1 μm. Dynamic recrystallization in the active zones was observed using TEM. The dynamic recrystallization was accompanied by the formation of disclinations, deformation bands, low-angle, and high-angle boundaries, i.e., rotational deformation modes developed. The dynamic recrystallization was more intense during the non-monotonous deformation as compared with the monotonous one, which was confirmed by the reduction of texture degree in the materials after ECAH.
G.V. Kurdyumov Institute for Metal Physics of National Academy of Sciences of Ukraine, 36, Academician Vernadsky Blvd., Kyiv-142, Kyiv, 03680, Ukraine.
Alla
A
Berezina
G.V. Kurdyumov Institute for Metal Physics of National Academy of Sciences of Ukraine, 36, Academician Vernadsky Blvd., Kyiv-142, Kyiv, 03680, Ukraine. tmonastyrska@gmail.com.
Tetiana
http://orcid.org/0000-0003-1095-3828
T
Monastyrska
O.O. Galkin Donetsk Institute for Physics and Engineering of National Academy of Sciences of Ukraine, 46, Prospect Nauki, Kyiv, 03039, Ukraine.
Olexandr
O
Davydenko
G.V. Kurdyumov Institute for Metal Physics of National Academy of Sciences of Ukraine, 36, Academician Vernadsky Blvd., Kyiv-142, Kyiv, 03680, Ukraine.
Oleh
O
Molebny
G.V. Kurdyumov Institute for Metal Physics of National Academy of Sciences of Ukraine, 36, Academician Vernadsky Blvd., Kyiv-142, Kyiv, 03680, Ukraine.
Sergey
S
Polishchuk
Aging; Al-Sc alloy; Deformation bands; Disclinations; Dynamic recrystallization; Equal-channel angular hydroextrusion; Hydrostatic extrusion; Low-angle and high-angle boundaries; Severe plastic deformation; Supersaturated solid solution