Effect of HPT straining and further natural aging on the structure and hardness of aluminum alloy 1965 with nanosized TM aluminides

M.V. Markushev, E.V. Avtokratova, S.V. Krymskiy, V.V. Tereshkin, O.S. Sitdikov показать трудоустройства и электронную почту
Получена  28 октября 2022; Принята  08 ноября 2022
Эта работа написана на английском языке
Цитирование: M.V. Markushev, E.V. Avtokratova, S.V. Krymskiy, V.V. Tereshkin, O.S. Sitdikov. Effect of HPT straining and further natural aging on the structure and hardness of aluminum alloy 1965 with nanosized TM aluminides. Письма о материалах. 2022. Т.12. №4s. С.463-468
BibTex   https://doi.org/10.22226/2410-3535-2022-4-463-468
HPT at 6 GPa pressure in the range of 0-10 rotations of pre-quenched ingot of the commercial aluminum alloy 1965 resulted in consequential transformation of well-defined dense dislocation wall/cell structure to non-equilibrium nanofragmented one and near two-fold hardenning. The alloy strengthening and/or softening during further natural aging up to 500 hrs were within 10-15% and controlled by simultaneous decomposition of the aluminum solid solution and recovery of its deformation structure.Pre-quenched samples cut from a homogenized ingot of commercial aluminum alloy 1965 with a grain size of about 21 µm were compressed at 6 GPa and then strained by torsion up to 10 revolutions at room temperature. TEM, SEM and XRD analyses showed that the strengthening / softening of the alloy during further natural aging up to 500 hrs was controlled by simultaneous decomposition of the aluminum solid solution and recovery of its deformation structure. It was found that the two-level nanostructuring of the alloy (precipitates and matrix) is accompanied by more than twofold strengthening up to a hardness of about 250 HV. The main contribution was made by dislocation and structural hardening due to the formation of a highly work-hardened structure of the nanofragmented type. During subsequent aging, the change in hardness was controlled by both the preliminary strain and the aging time. A continuous increase in strength with strain and aging time was found in the samples after pressing and torsion up to 1 revolution. In other conditions, strengthening was preceded by softening, the magnitude and duration of which were also proportional to the strain. The nature of the alloy behavior and the role of nanosized aluminides of transition metals are discussed in details.