Browsing by Author "Nigmatullina, Alfiia"

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    Mechanism of large strain accommodation assisted by shear localization in a precipitation-hardened Cu–Be alloy
    (Elsevier Science, 2021-08-17) Lomakin, Ivan; Nigmatullina, Alfiia; Sauvage, Xavier; Department of Applied Physics; St. Petersburg State University; Université de Rouen
    The influence of the structural state on deformation mechanisms under large strains was investigated in a Cu – 2 wt.% Be alloy. Torque evolutions during straining exhibit serrations typical of structural relaxations in the precipitation-hardened alloy, but not in the solid solution state. Microstructure characterization revealed that homogeneous deformation of the solid solution led to strong grain size reduction (20 nm), while localization occurred in the precipitated state with numerous shear bands. The role of CuBe precipitates on hindering dislocation glide and the resulting shear localization under large strain is discussed.
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    Nanostructuring of beryllium bronze : Contribution of grain boundaries segregation and solid solution
    (Elsevier Science B.V., 2024-02-15) Lomakin, Ivan; Nigmatullina, Alfiia; Sauvage, Xavier; Department of Applied Physics; Complex Systems and Materials; St. Petersburg State University; Université de Rouen
    The impact of composition on grain refinement in solutionized Cu-Be alloys was investigated. High-pressure torsion resulted in grain sizes of 10–110 nm for Cu–1 wt.% Be and 10–20 nm for Cu-2 wt.%Be. Our findings indicate that Be stabilizes the nanoscale grain size, which is influenced by the balance between defect creation and annihilation. Consequently, Be concentration serves as a key parameter for directing microstructure and property changes during severe plastic deformation.