Nanostructured Strain-Hardened Aluminum–Magnesium Alloys Modified by C60 Fullerene Obtained by Powder Metallurgy: 2. The Effect of Magnesium Concentration on Physical and Mechanical Properties.

Autor: Evdokimov, I. A., Khayrullin, R. R., Bagramov, R. Kh., Perfilov, S. A., Pozdnyakov, A. A., Aksenenkov, V. V., Kulnitskiy, B. A.
Zdroj: Russian Journal of NonFerrous Metals; May2021, Vol. 62 Issue 3, p368-374, 7p
Abstrakt: This paper continues studies into magnesium effects on the structural phase composition and physical and mechanical properties of nanostructured strain-hardened aluminum-magnesium alloys modified with C60 fullerene [1]. Previously obtained mechanically alloyed composite powders [1] were consolidated by direct hot extrusion. Consolidation parameters were chosen based on previous studies of the structure and phase-composition formation during mechanical alloying and heat treatment. It was found that an increase in the magnesium concentration improves the mechanical properties of extruded nanosructured composite materials and additives modified by C60 fullerene stabilize the grain structure and slow down the decomposition of a solid solution of magnesium in aluminum to 300°C. Under similar thermobaric treatment, Al82Mg18 (AMg18) unmodified by C60 demonstrates a reduced solid solution lattice constant and an increased average crystallite size. These processes are accompanied by the sequential formation of γ, β', and β phases, while γ and β' are intermediate phases. The grain structure of extruded samples is typical for materials obtained in this way—grains are closely packed, elongated, and oriented along the extrusion axis. The grain structure of the extruded samples inherits the morphology of mechanically alloyed powders. Thus, mechanical alloying methods followed by intense plastic deformation (extrusion) significantly improved mechanical properties. Materials with an ultimate tensile strength of 880 MPa, ultimate bending strength of 1100 MPa, microhardness up to 3300 MPa, and the same density of 2.4–2.6 g/cm3 were obtained. This result demonstrates the prospects for using powder metallurgy techniques in the production of new nanostructured composite materials modified by C60 fullerene with improved physical and mechanical properties. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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