New synthesis methods of MgAl2O4 spinel

Păcurariu, Cornelia; Lazău, Ioan; Ecsedi, Zoltán; Lazău, Radu; Barvinschi, Paul; Mărginean, Gabriela

doi:10.1016/j.jeurceramsoc.2006.04.050

Cited by 115 publications

(64 citation statements)

References 18 publications

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“…There are several processes to prepare nanocrystalline magnesium aluminate, such as sol-gel [13][14][15][16] , co-precipitation 17 , complexation 1,18 , mechanical milling 3 , mechanical-chemical process 19 , hydrothermal 20 , micro emulsion 21 , combustion method 15,[22][23][24][25][26] and fast pyrolysis 27 . However, many of those are complex, expensive, have several steps, require long time for synthesis, require high temperatures and produce nonhomogeneous and generally low surface area solids 28 .…”

Section: Introductionmentioning

confidence: 99%

Effect of Urea Excess on the Properties of the MgAl2O4 Obtained by Microwave-Assisted Combustion

et al. 2017

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In this paper, magnesium aluminate spinels were prepared by microwave-assisted combustion, using urea as fuel. In order to evaluate the effect of the urea excess used in the synthesis, its mass was added in a range of 1.0 to 2.5 times the stoichiometric amount required. The materials produced were characterized by TGA, FTIR, XRF, XRD, BET, SEM and TEM. The results demonstrated that magnesium aluminate spinel was formed in all solids, but the crystallinity degree and the specific surface area increased according to the amount of urea that was used in the synthesis. The use of excess fuel in the preparation was therefore advantageous, since it eliminated the need of the calcination step, at high temperatures, in order to stabilize the spinel phase and improve the crystallinity of the solid. The heat generated in the combustion process was sufficient to develop the formation of a nanocrystalline structure and produce high purity materials, with a save of 99.4% in energy.

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Section: Introductionmentioning

confidence: 99%

Effect of Urea Excess on the Properties of the MgAl2O4 Obtained by Microwave-Assisted Combustion

et al. 2017

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“…The MgAl 2 O 4 phase shows a combination of unique properties such as low electrical conductivity, low thermal expansion coefficient, good thermal shock resistance, low dielectric constant, high electrical resistance, high melting point (2135°C) and high mechanical strength. 17,18 Moreover, this compound has a good adhesion to metal matrices. 19 Various studies are carried out regarding the formation, interface type and crystallography of the Table 2: Reactions could occur between the main elements in the molten material and nano-silica particles…”

Section: Thermodynamic Analysis Of Phase Formations In the Mg-sio 2 Smentioning

confidence: 99%

Synthesis and characterization of an in-situ magnesium-based cast nano composite via nano-SiO2 additions to the melt

Borouni¹,

Niroumand²,

Maleki³

2017

Mater. Tehnol.

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In this study, AZ91C magnesium matrix in-situ nano-composites reinforced with oxide particles were produced by the addition of 2 % of mass fractions of silica nanoparticles to the melt using the stir-casting method. For this purpose, nano-silica powder was mixed in molten AZ91C by a special procedure and stirred for 15 min at 750°C and cast in a preheated die at 720°C. Control samples were also cast under the same conditions. Improved microstructure, reduced porosity and increased hardness, tensile strength and yield strength of the composite sample were revealed by microstructural and mechanical investigations. The hardness, yield strength and tensile strength values increased from 65 BHN, 82 MPa and 165 MPa for the monolithic samples to 77 BHN, 97 MPa and 175 MPa for the in-situ formed cast composites. Microstructural and EDS analyses suggested the in-situ formation of Al2O3, MgAl2O4 and MgO oxide particles by in-situ reaction of the Al, Mg and SiO2 in the melt. Keywords: AZ91C alloy, in-situ cast nano-composite, silica nanoparticles, mechanical properties V {tudiji so bili izdelani AZ91C nanokompoziti in situ, na podlagi magnezijeve matrike in oja~ani z oksidnimi delci z dodatkom 2 % nanodelcev silicija za topljenje, z uporabo metode litja z me{anjem. Za ta namen je bil nanosilicijev prah zme{an v raztopljen AZ91C s posebno metodo in nato 15 min me{an na 750°C in lit v predogretem modelu na 720°C. Preizku{anci so bili ravnotako liti v enakih pogojih. Izbolj{ana mikrostruktura, zmanj{ana poroznost in pove~ana trdota, napetostna trdnost in napetost vzorcev kompozita so bili odkriti s preiskavami mikrostrukture in z mehanskimi preiskavami. Vrednosti trdote, napetosti te~enja in natezne napetosti so se pove~ali iz 65 BHN, 82 Mpa in 165 MPa in za monolitne vzorce na 77 BHN, 97 MPa in 175 MPa za in situ formirane lite kompozite. Mikrostrukture in EDS-analize so predlagale in situ formacijo Al2O3, MgAl2O4 in MgO oksidne delce z in situ reakcijo Al, Mg in SiO2 v topljenem. Klju~ne besede: AZ91C zlitina, in situ litje nanokompozitov, nanodelci silicija, mehanske lastnosti

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“…Various substitutions may be incorporated into it, so adequate selection of substituting ion and appropriate chemical composition are of the utmost importance in order to achieve desired properties of material, including its catalytic performances. Synthesis method is also a significant factor influencing the properties of the obtained material such as crystallite size, specific surface area or porosity [1][2][3].…”

Section: Introductionmentioning

confidence: 99%

“…solid state reaction (ceramic, mechanochemical) method [8] or wet chemical routs such as (co)precipitation [9], sol-gel [10], solvothermal methods [11] and some other methodologies like molten salts synthesis [12], combustion in various solutions [3], polymeric precursors method [13], etc. Glycothermal method, being one type of the solvothermal process, offers some advantages over most other methods like short reaction time, the possibility of using various precursors and reaction media.…”

Section: Introductionmentioning

confidence: 99%

“…, in the framework of zinc aluminate spinel on phenol conversion and ortho-methylated products selectivity during methylation. Zn 1-x Co x Al 2 O 4 (x = 0, 0.5, 1) spinels, prepared under microwave-assisted glycothermal conditions, were characterized using XRD, TEM/SEM, N 2 adsorptiondesorption, TPD-NH 3 and CHOL test to find a relationship between the structure, acid-base properties and the catalytic behaviour. 4 OH (Alfa Aesar).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Glycothermal Synthesis and Catalytic Properties of Nanosized Zn1−x Co x Al2O4 (x = 0, 0.5, 1.0) Spinels in Phenol Methylation

2011

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Zn 1-x Co x Al 2 O 4 (x = 0, 0.5, 1.0) spinels were synthesised under microwave-assisted solvothermal conditions using 1,4-butanediol as reaction medium. The results of XRD and HRTEM have indicated nanocrystallinity of prepared materials (average crystallite size in the range 6-16 nm), and N 2 adsorption-desorption measurements have revealed high feature of their surface area and mesoporous nature. Acid-base properties of prepared materials were determined using TPD-NH 3 method and cyclohexanol test. All studied spinels that underwent examination were active in phenol methylation but Co-substituted zinc aluminate (Zn 0.5 Co 0.5 Al 2 O 4 ) was found to be the most efficient in the selective formation of orthomethylated products. It could be ascribed to its dominant basic character and the presence of weak and strong acid centres, and the highest surface area as well.

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New synthesis methods of MgAl2O4 spinel

Cited by 115 publications

References 18 publications

Effect of Urea Excess on the Properties of the MgAl2O4 Obtained by Microwave-Assisted Combustion

Effect of Urea Excess on the Properties of the MgAl2O4 Obtained by Microwave-Assisted Combustion

Synthesis and characterization of an in-situ magnesium-based cast nano composite via nano-SiO2 additions to the melt

Glycothermal Synthesis and Catalytic Properties of Nanosized Zn1−x Co x Al2O4 (x = 0, 0.5, 1.0) Spinels in Phenol Methylation

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