Nanostructured Strain-Hardened Aluminum–Magnesium Alloys Modified by C60 Fullerene Obtained by Powder Metallurgy: Part 1. The Effect of the Magnesium Concentration on the Structure and Phase Composition of Powders

This paper is intended to continue the studies of magnesium effects on the structural phase composition, physical and mechanical properties of the nanostructured strain-hardened aluminum-magnesium alloys modified with C60 fullerene [1]. Previously obtained mechanically alloyed composite powders [1] were consolidated by direct hot extrusion method. 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 magnesium concentration improves mechanical properties of extruded nanosructured composite materials, and additives modified by C60 fullerene stabilize the grain structure and slow down decomposition of α solid solution of magnesium in aluminum to 300 °C. Under similar thermobaric treatment Al82Mg18 (AMg18) not modified with C60 demonstrates a reduced α solid solution lattice constant and an increased average crystallite size. These processes are accompanied by 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 extruded samples inherits the morphology of mechanically alloyed powders. Thus, mechanical alloying methods followed by intense plastic deformation (extrusion) improved mechanical properties significantly. Materials with ultimate tensile strength of 880 MPa; ultimate bending strength of 1100 MPa; microhardness up to 3300 MPa; and with 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.

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Nanostructured strain hardened aluminum-magnesium alloys modified by C60 fullerene obtained by powder metallurgy. Part 1. Effect of magnesium concentration on the structure and phase composition of powders

Izvestiya Vuzov Poroshkovaya Metallurgiya i Funktsional’nye Pokrytiya (Universitiesʹ Proceedings Powder Metallurgy аnd Functional Coatings) ◽

10.17073/1997-308x-2020-3-76-84 ◽

2020 ◽

pp. 76-84

Author(s):

I. A. Evdokimov ◽

R. R. Khayrullin ◽

R. Kh. Bagramov ◽

V. V. Aksenenkov ◽

S. A. Perfilov ◽

...

Keyword(s):

Phase Composition ◽

Mechanical Activation ◽

Structural Phase ◽

Physical And Mechanical Properties ◽

Magnesium Concentration ◽

Scanning Calorimetry ◽

Composite Powders ◽

Aluminum Magnesium Alloys ◽

Average Size ◽

Powder Metallurgy Part

This paper provides the first part of the study on the magnesium effect on the structural phase composition, physical and mechanical properties of nanostructured aluminum-magnesium composite materials with the composition AlxMgy + 0.3 wt.% C60 fullerene. Composite powders were obtained by the simultaneous mechanical activation of initial materials in a planetary ball mill in an argon atmosphere. It was found that the obtained powders have a complex hierarchical structure made up of 50–200 μm aggregates consisting of 5–10 μm strong high-density agglomerates, which in turn are a combination of nanoscale (30–60 nm) crystallites. It was found that the increase in magnesium concentration in the composite up to 18 wt.% makes it possible to obtain crystallites with an average size of less than 30 nm during mechanical activation, while the size of aggregates is less than 50 μm. The maximum solubility of magnesium in aluminum with a crystallite size of 30–70 nm during mechanical activation was 15 wt.% (17 at.%). Using the differential scanning calorimetry method, it was found that nanostructured composites undergo irreversible structural phase transformations during heat treatment in a temperature range of 250–400 °C: recrystallization, decomposition of the α-solid solution of magnesium in aluminum and formation of intermetallic β-(Al3Mg2), γ-(Al12Mg17) and carbide (Al4C3) phases. In addition, the Raman spectra contain peaks that, according to some sources, correspond to covalent compounds of aluminum with C60 fullerene – aluminum-fullerene complexes. The data obtained will be used in further research to determine parameters for the thermobaric treatment of nanocmposite powder mixtures in order to obtain and test bulk samples.

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Structure and Phase Composition of Ceramic Materials Prepared from Aluminum Hydroxide Powder by Chemical Dispersion of Aluminum-Magnesium Alloys

Refractories and Industrial Ceramics ◽

10.1007/s11148-014-9612-4 ◽

2014 ◽

Vol 54 (5) ◽

pp. 362-365 ◽

Cited By ~ 2

Author(s):

A. Yu. Omarov ◽

Yu. G. Trifonov

Keyword(s):

Phase Composition ◽

Magnesium Alloys ◽

Aluminum Hydroxide ◽

Ceramic Materials ◽

Chemical Dispersion ◽

Aluminum Magnesium Alloys

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Multifactor mathematical model of criticality of welding process of products from aluminum- magnesium alloys

10.36652/0042-4633-2020-3-12-18 ◽

2020 ◽

pp. 12-18

Author(s):

F.A. Urazbahtin ◽

A.YU. Urazbahtina

Keyword(s):

Mathematical Model ◽

Magnesium Alloy ◽

Magnesium Alloys ◽

Welding Process ◽

Welding Equipment ◽

Equipment Operation ◽

Aluminum Magnesium Alloys ◽

Aluminum Magnesium Alloy ◽

Welding Materials

A multifactor mathematical model of the welding process of products from aluminum-magnesium alloys, consisting of 71 indicators that assess the quality of the weld, the welding process, costs, equipment operation and quality of the welded material. The model can be used to control and optimize the welding process of products from aluminum-magnesium alloys. Keywords welding, products, aluminum-magnesium alloy, indicators, process parameters, welding equipment, welding materials, electrode sharpening, lining [email protected]

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