Kinetic analysis of the formation of magnesium aluminate spinel (MgAl2O4) from α-Al2O3 and MgO nanopowders

Saheb, Nouari; Lamara, Smail; Sahnoune, F.; Hassan, S.F.

doi:10.1007/s10973-022-11344-1

Cited by 14 publications

(3 citation statements)

References 54 publications

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“…A substantial difference in the chemical (elemental) composition of the obtained oxide layers is noteworthywith the same concentration of sodium aluminate or sodium metasilicate in the electrolyte, the amount of aluminum in the layer is about 1.5-3 times greater than that of silicon (based on two methods data). Apparently, this is due to the higher reaction rate of spinel formation MgO + Al2O3 = MgAl2O4 [41] compared with the reaction of magnesium silicate formation MgO + SiO2 = MgSiO3 [42].…”

Section: Discussionmentioning

confidence: 99%

Improvement of protective oxide layers formed by high-frequency plasma electrolytic oxidation on Mg-RE alloy with LPSO-phase

et al. 2023

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Oxide layers on Mg97Y2Zn1 magnesium alloy with strengthening LPSO-phase were formed by plasma electrolytic oxidation (PEO) in bipolar mode with frequency variation of forming current pulses (50 and 500 Hz) and addition of sodium aluminate or sodium silicate to alkali phosphate fluoride electrolyte. Microstructure, chemical and phase composition, corrosion and mechanical properties of the oxide layers formed were investigated. With increasing current frequency for both electrolytes, an increase in homogeneity of the oxide layers structure and a decrease in their porosity and fracturing at constant thickness were recorded. The oxide layers formed at 500 Hz even with some decrease in hardness have better adhesive strength and 2 orders of magnitude higher short-term corrosion resistance values. PEO of Mg-alloy with LPSO-phase in the electrolyte with addition of sodium aluminate in combination with increased pulse frequency (500 Hz) allows forming the best-quality uniform oxide layer with high hardness, adhesive strength and corrosion resistance properties. The use of electrolyte with addition of sodium silicate reduced the adhesive strength by 1.5 times and brought down the long-term corrosion resistance of oxide layers by an order of magnitude, as compared with the electrolyte with sodium aluminate. The reason for a significant improvement in the complex of protective properties of the oxide layers with an increase in the current pulse frequency is supposed to be a decrease in the power and duration of individual microarc discharges with simultaneous increase in their number per unit oxidized area.

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Section: Discussionmentioning

confidence: 99%

Improvement of protective oxide layers formed by high-frequency plasma electrolytic oxidation on Mg-RE alloy with LPSO-phase

et al. 2023

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“…The formation of in situ magnesium aluminate in aluminium composites have been explored extensively with varied sources of oxygen to form the magnesium aluminate particles in aluminium-magnesium alloy [16,17]. Studies on addition of oxide sources include aluminium oxide, silicon dioxide, titanium dioxide, magnesium oxide and boric acid for the generation of magnesium aluminate particles [18][19][20][21][22][23][24][25]. Rarely, certain studies have approached the formation of magnesium aluminate using nickel oxide and yttrium oxide as reinforcement [26,27].…”

Section: Introductionmentioning

confidence: 99%

Fatigue performance of the aluminium‐magnesium/magnesium aluminate in‐situ composites synthesized through manganese dioxide and copper oxide reinforcement

Chockalingam

Raman²,

Olubambi

2023

Materialwissenschaft Werkst

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Aluminium‐2magnesium alloy castings find its application in engineering sectors where fatigue property is a key requirement. Few researches have been carried out in the past to improve its fatigue property by micro, nano reinforcements. However, the requirement of intended application has not yet attained and hence this current research study has been taken up to provide a solution. This research work focuses through a novel approach for synthesizing in‐situ magnesium aluminate particles in aluminium‐2magnesium alloy by the addition of manganese dioxide and copper oxide precursor addition (1 wt.%, 1.5 wt.% and 2 wt.%) during the casting process. Microstructure of fabricated composites were examined through field emission scanning electron microscopy to characterize the morphology and distribution of magnesium aluminate particles. The fabricated aluminium‐2magnesium/magnesium aluminate in‐situ composite specimens were subjected to low cycle fatigue testing at two different strain amplitudes of 0.3 % and 0.4 % and a frequency of 0.3 Hz. Among all composite specimens, specimens reinforced with 2 wt.% manganese dioxide and 2 wt.% copper oxide outperformed when tested in strain amplitudes of 0.3 % and 0.4 % respectively. Fractography studies were performed on failed composite specimens to study the modes of failure that resulted after fatigue testing.

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“…Bead milling (BM) is a common method for preparing the initial mixture for MAS synthesis. Recently, this method has been used to fabricate γ-Al 2 O 3 + MgO, θ/α-Al 2 O 3 + MgO, α-Al 2 O 3 and MgO nanopowders as well as MgO–Al 2 O 3 –GeO 2 mixtures. − Mechanical activation is an important method for reducing particle sizes, shortening diffusion lengths, and accelerating reactions. − Moreover, material deformation and defect formation also occur during mechanical activation, which generally increases the free energy of the system.…”

Section: Introductionmentioning

confidence: 99%

Solid-State Reaction Synthesis of MgAl₂O₄ Spinel from MgO–Al₂O₃ Composite Particles Prepared via Electrostatic Adsorption

Tran,

Nguyet

et al. 2023

ACS Omega

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This paper presents the formation of magnesium aluminate spinel using composite particles prepared via electrostatic adsorption (ESA). Scanning electron microscopy (SEM) images confirmed the presence of Al2O3–MgO composite particles. A mixture of Al2O3 and MgO raw materials was also prepared by using the conventional bead-milling method for comparison. The samples sintered at elevated temperatures were characterized through X-ray diffraction, SEM, and relative density measurements. Additionally, the lattice parameter and strain of the samples were determined using the Nelson–Riley function and the Williamson–Hall equation. A pure spinel phase formed in the ESA-derived sample sintered at 1400 °C, while the MgO structure remained in the conventionally prepared sample sintered at 1600 °C. The densities of samples sintered at 1450 °C or higher exceeded 90%. The lattice strain of the prepared samples was inversely proportional to the sintering temperature, attributed to the formation of large grains at higher temperatures. However, the sample sintered at 1600 °C for 8 h exhibited the highest strain of 0.0074 because the crystals grew in a certain direction.

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Kinetic analysis of the formation of magnesium aluminate spinel (MgAl2O4) from α-Al2O3 and MgO nanopowders

Cited by 14 publications

References 54 publications

Improvement of protective oxide layers formed by high-frequency plasma electrolytic oxidation on Mg-RE alloy with LPSO-phase

Improvement of protective oxide layers formed by high-frequency plasma electrolytic oxidation on Mg-RE alloy with LPSO-phase

Fatigue performance of the aluminium‐magnesium/magnesium aluminate in‐situ composites synthesized through manganese dioxide and copper oxide reinforcement

Solid-State Reaction Synthesis of MgAl₂O₄ Spinel from MgO–Al₂O₃ Composite Particles Prepared via Electrostatic Adsorption

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Kinetic analysis of the formation of magnesium aluminate spinel (MgAl2O4) from α-Al2O3 and MgO nanopowders

Cited by 14 publications

References 54 publications

Improvement of protective oxide layers formed by high-frequency plasma electrolytic oxidation on Mg-RE alloy with LPSO-phase

Improvement of protective oxide layers formed by high-frequency plasma electrolytic oxidation on Mg-RE alloy with LPSO-phase

Fatigue performance of the aluminium‐magnesium/magnesium aluminate in‐situ composites synthesized through manganese dioxide and copper oxide reinforcement

Solid-State Reaction Synthesis of MgAl2O4 Spinel from MgO–Al2O3 Composite Particles Prepared via Electrostatic Adsorption

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Solid-State Reaction Synthesis of MgAl₂O₄ Spinel from MgO–Al₂O₃ Composite Particles Prepared via Electrostatic Adsorption