Influence of inversion level on the optical absorption spectra of Ti-doped transparent MgGa2O4 ceramics

Ti-doped (0.08, 0.30, and 1.00 atomic% [at.%]) transparent MgGa₂O₄ ceramics (possessing a high inversion level; i up to 0.8) were fabricated by pulsed electric current sintering, at 950°C, under vacuum for 30–90 min. Optical transmission, emission, and electron paramagnetic resonance spectra were recorded. The maximal transmission level was ∼70% (820 nm), for a thickness of ∼1 mm, which, while not very high, permitted the observation of the optical absorption bands location and profile. Interpretation of the fluorescence spectra suggests that some Ti⁴⁺ cations (mostly hexacoordinated) were accommodated by the host despite the scarcity of oxygen in the atmosphere during the sintering process. The Ti³⁺ cations substitute native ions located in tetrahedral sites, distorting the original T_d symmetry toward a D_2d symmetry. Comparing the Ti-doped MgGa₂O₄ (high inversion) and MgAl₂O₄ (low inversion) spinels, spectral characteristics revealed that a significant increase in the inversion level drives Ti³⁺ cations from octahedral toward tetrahedral sites. This is reflected in the optical absorption spectra by the disappearance of the band at ∼20 000 cm⁻¹ (detectable in MgAl₂O₄) in MgGa₂O₄; the two d–d bands, of MgA₂O₄, in MgGa₂O₄ are reduced to a single one, located at 11 800 cm⁻¹. These results, for MgGa₂O₄, strongly support a similar assignment—of the strong band at 12 800 cm⁻¹, in Ti-doped MgAl₂O₄—to a tetracoordinated Ti³⁺. Thus, while in MgAl₂O₄, Ti³⁺ appears in both octahedral and tetrahedral coordination and in MgGa₂O₄ only the latter state is stable. In both spinels, Ti dopant speciates into Ti³⁺ and Ti⁴⁺ cations.     

Formation mechanism of whiskers in Al–MgAl2O4–MgO refractories at 1400 °C under N2 atmosphere

Al–MgAl₂O₄–MgO refractories were prepared using fused magnesia, metal Al, fused spinel and sintered high purity magnesia as raw materials. The phase composition and microstructure of Al–MgAl₂O₄–MgO refractories treated at 1400 °C under N₂ atmosphere were investigated by means of XRD, SEM and EDS. The results showed that magnesia (MgO) whiskers and MgAlON whiskers were formed on the surface and in the inner area of the Al–MgAl₂O₄–MgO refractories, respectively. The MgO whiskers grew preferentially along the axial direction, forming cylindrical shape MgO whiskers. Then the cylindrical MgO whiskers further absorbed Mg(g) and O₂(g), and grew along the radial direction to form the square columnar shape MgO whiskers. The MgAlON whiskers firstly grew in one-dimensional direction, forming whisker shape MgAlON, then some whisker shape MgAlON gradually developed and grew into two-dimensional flake shape MgAlON. The sintering and thermal shock resistance was significantly improved by the whiskers. The growth process of magnesia whiskers and MgAlON whiskers were dominated by a vapor-solid (VS) mechanism.     

Microwave dielectric properties and crystal structures of spinel-structured MgAl2O4 ceramics synthesized by a molten-salt method

The microwave dielectric properties and crystal structures of MgAl₂O₄ ceramics synthesized using either molten-salt (MA-M) or solid-state reaction (MA-S) methods were characterized in this study. Raman and ²⁷Al solid-state nuclear magnetic resonance spectra indicated that Al³⁺ cations primarily occupied in tetrahedral sites of the MA-M ceramic. The degree of inversion x, i.e., degree of cation disorder in tetrahedral and octahedral sites, of the MA-M was higher than that of MA-S; such the preferential site occupation of Al³⁺ cations enhanced the covalency of the MO bonds in the MO₄ tetrahedra (M = Mg and Al), leading to a decrease in the lattice parameters. The Q·f of the MA-M fired at 1600 °C was 201,690 GHz, while the MA-S synthesized at 1600 °C exhibited a Q·f of just 85,100 GHz. Based on these results, an intermediate spinel structure with a greater x evidently has a higher Q·f, and therefore the cation distribution is closely related to the Q·f of the ceramic.     

Influence of Mg Addition on the Catalytic Activity of Alumina Supported Ag for C3H6-SCR of NO

The influence of different magnesium (Mg) weight percentages (1, 2.5, 5, 7.5 and 10) over silver (3 wt%) impregnated alumina (SA) catalyst was investigated for the reduction of NO by C₃H₆. Mg doped SA catalysts were prepared by conventional impregnation method and characterized by XRD, BET-SA, ICP-MS, XPS, SEM, UV-DRS, H₂-TPR and O₂-TPD. The existence of MgO and MgAl₂O₄ phases on Mg doped SA catalysts were observed from XRD and XPS analyses. Existence of high percentage MgAl₂O₄ phase on 5% Mg doped SA catalyst (Mg (5) SA) enhances the dispersion and stabilization of silver phases (Ag₂O). Mg (5) SA catalyst shows a 51% of high selectivity (NO to N₂) in presence of SO₂ (80 ppm) at low temperatures (350 °C) and maintained high selectivity’s with a wide temperature window (350–500 °C). An optimal high surface availability of Ag⁰ and Ag⁺ species were observed from XPS analysis over Mg (5) SA catalyst. H₂-TPR analysis shows high temperature reduction peak over Mg (5) SA compared to SA catalyst. XPS analysis confirms the high percent availability of MgAl₂O₄ species over Mg (5) SA catalyst. DRIFTS study reveals the molecular evidences for the evolution of enolic species during NO reduction over the highly active Mg (5) SA catalyst at low temperatures. It also confirms further transformation of enolic species into –NCO species with NO + O₂ and finally into N₂ and CO₂.     

Microstructures and strength of microporous MgO-Mg(Al,Fe)2O4 refractory aggregates

Microporous MgO-Mg(Al, Fe)₂O₄ refractory aggregates were prepared using magnesite, Al(OH)₃ and Fe₂O₃ applying an in-situ decomposition synthesis method. At 1400–1600 °C, there was a Mg(Al, Fe)₂O₄ with Fe³⁺, which had two structures. One was a ring structure formed from Al(OH)₃ pseudomorph particle as a template and a low content of Fe³⁺. The other was the dot and strip structures precipitated in magnesite pseudomorph particles with a high content of Fe³⁺. Besides, at 1550–1600 °C, microporous MgO-Mg(Al, Fe)₂O₄ refractory aggregates had an excellent compressive strength (75.8–81.5 MPa) and apparent porosity (26.8%?28.2%).     

Degradation mechanism of MgO–MgAl2O4 dual-phase refractory in contact with the automobile gear steel SCr420H with Si–Mn,Al and Ce–Al deoxidation

The current research, the degradation mechanism of MgO–MgAl₂O₄ dual-phase crucibles in contact with steel SCr420H with Si–Mn, Al, and Ce–Al deoxidation was investigated using a laboratory steelmaking experiment at 1873 K. The refractory interface in contact with the steel and inclusions was analysed using SEM and EPMA. In the case of Si–Mn deoxidation, the refractory's MgO phase was initially attacked by the dissolved Si, resulting in its transformation into the 2MgO–SiO₂ phase, as confirmed by thermodynamic calculations. In the case of Al deoxidation, the reaction between the dissolved Al and the refractory had a significant effect on the increase in Mg concentration and MgAl₂O₄ inclusions. Refractory degradation was suppressed because the MgAl₂O₄ phase was an equilibrium phase based on thermodynamic consideration. The distribution of the MgAl₂O₄ phase in the refractory hindered the degradation reaction. The primary degradation mechanism in the case of Al deoxidation was steel penetration. In Ce–Al deoxidation, both Ce and Al were involved in refractory degradation. During this process, the MgO phase reacted with the dissolved Al, leading to its transformation into the MgAl₂O₄ phase, which was subsequently modified to the Ce–Al–O phase. Additionally, the MgAl₂O₄ phase was directly denatured into the Ce–Al–O phase.     

Soft-templating pathway to create nanostructured Mg–Al spinel as high-temperature absorbent for SO2

Interest in reducing SO₂ emission from the fluid catalytic cracking (FCC) crude oil has been encouraging the development of new materials to achieve such goal. The nanostructured Mg–Al spinel (MgAl₂O₄) was prepared by co-precipitation and post hydrothermal treatment in the presence of glucose and followed by elimination of the organic components by calcination at 700 °C for 3 h. Physical and chemical properties were characterized by XRD, N₂ sorption, TG, FTIR, SEM, and TEM methods. Mesoporous nanostructured MgAl₂O₄ with a high surface area of 324 m² g^?1 were obtained. The organic components contributed to the development of mesoporosity, functioning as a soft template. SO₂ adsorption tests showed that the nanostructured MgAl₂O₄ had a 51.58 % increase of SO₂ sorption capacity than MgAl₂O₄ prepared without glucose. These results showed that the nanostructured MgAl₂O₄ is a promising candidate as catalyst for flue gas desulfurization in FCC process. Three kinetic models were also applied to analyze the SO₂ adsorption kinetics; the pseudo-second order kinetic model fit well with a correlation coefficient (R²) of 0.991 for nanostructured MgAl₂O₄.     

Spinel Mg(Al,Ga)2O4 Solid Solution as High‐Performance Microwave Dielectric Ceramics

Spinel Mg(Al_1?xGa_x)₂O₄ (x = 0–1) solid solutions were synthesized via solid‐state method. Replacement of Al³⁺ by Ga³⁺ in MgAl₂O₄ gave rise to the expansion of the lattice, as well as blueshifts of FT‐IR and Raman peaks. The homogeneous solid solutions, high relative densities, large grain sizes, and compact microstructures resulted in excellent microwave dielectric properties for spinel Mg(Al_1?xGa_x)₂O₄ (x = 0.6) ceramics sintered at 1485°C: that is, ε_r = 8.87, Q × f = 107 000 GHz (at 14.8 GHz), and τ_f = ?16 ppm/°C. Spinel‐structured Mg(Al_1?xGa_x)₂O₄ (x = 0–1) solid solutions possessed low sintering temperatures, wide temperature regions (~100°C), and small negative τ_f values. These outstanding performance make Mg(Al, Ga)₂O₄ a promising candidate material for millimeter‐wave devices.     

Phase evolution and microstructure of SiC–MgAl2O4–Al composites sintered in argon atmosphere at 1450 °C: Reactions in Al–O–C system

SiC–MgAl₂O₄–Al composites were prepared using SiC, MgAl₂O₄, corundum and Al powder as raw materials by firing at 1450 °C in flowing argon. The effects of binders on phase composition and microstructure evolution were investigated. The results show that the external of specimens with thermosetting phenolic resin and water soluble resin as binders both contained SiC, MgAl₂O₄, corundum and Al₄O₄C phases. In center of the specimens, Al₄C₃ and Al₂OC phases appeared in the thermosetting phenolic resin bonded specimens while Al₄O₄C and Al₂OC phases appeared in the water soluble resin bonded specimens. The microstructure shows that MgAl₂O₄ whiskers generated at surface of both specimens through gas-gas reaction. As for the specimens with thermosetting phenolic resin as binder, the residual carbon (decomposed from phenolic resin) and Al in the external of the specimen react with O₂ to form CO and Al₂O, which promoting the formation of plate-like Al₄O₄C. In the center of the specimen, Al₄C₃, Al₂O₃ and Mg(g) formed. Mg(g) migrates to outside and transforms to MgAl₂O₄ whiskers, and a part of Al₄C₃ transform to columnar Al₂OC. Al₂OC whiskers can also be generated through the reaction among Al₂O, CO and C. Compared with the thermosetting phenolic resin bonded specimens, Al at external of the water soluble resin bonded specimen reacts with O₂ to form Al₂O₃, which further transforms to particle Al₄O₄C. In the center of water soluble resin bonded specimen, a little Al₄C₃ formed and can totally transform to Al₄O₄C and Al₂OC.     

In situ hot elastic modulus evolution of MgO–C refractories containing Al,Si or Al–Mg antioxidants

Metals and alloys (such as Al, Si, Al–Mg and Al–Si) are commonly added to MgO–C refractory bricks as antioxidants due to their effectiveness to prevent carbon oxidation (in the 600–1400 °C range) and their low cost. These additives act at different temperatures and react with refractory components and gases in the environment, inducing significant changes in the resultant microstructure and affecting the overall thermo-mechanical performance of these products. This work addresses the evaluation of physical properties, cold and hot mechanical resistance, as well as in situ hot elastic modulus (E) measurements in the temperature range of 30–1400 °C for MgO–C bricks containing antioxidants (Al, Si or Al–Mg alloy) in a reducing atmosphere. Cured and fired samples of the designed formulations were evaluated throughout 1 or 2 heating-cooling cycles. Despite the improved mechanical behavior (higher cold crushing strength and hot modulus of rupture) of the antioxidant-containing formulations, compared to the additive-free MgO–C sample, the interaction of the selected additives with the refractory components and CO_(g) led to a generation of phases (i.e., Al₄C₃, Al₂O₃, SiC, SiO₂, MgAl₂O₄) that could not be well accommodated in the microstructure. Consequently, the in situ E drop was observed during cooling (mainly below 600 °C) of the antioxidant-containing sample due to crack and flaw formations. Si and Al–Mg were the most promising antioxidants, whereas the Al-containing composition showed the highest E damage level after two heating/cooling cycles up to 1400 °C for cured samples. Based on the elastic modulus profiles with the temperature, the results also indicated the best working conditions for these ceramic materials.     

Microstructure,mechanical and optical properties of MgAl2O4/MgAl2O4 joints bonded using CaO-Al2O3-SiO2 glass filler

Transparent MgAl₂O₄ ceramics were bonded by using CaO-Al₂O₃-SiO₂ (CAS) glass filler. The CAS glass filler exhibited the same thermal expansion behavior as MgAl₂O₄ ceramic and excellent wetting ability on the surface of MgAl₂O₄ ceramic. When the cooling rate of 15 °C/min was used, no interfacial reaction was observed and the amorphous brazing seam could be obtained. However, low joining temperature (1250 °C) led to the formation of pores and high joining temperature (1400 °C) resulted in the formation of cracks. Furthermore, the slow cooling rate of 5–10 °C/min induced the crystallization of CaAl₂Si₂O₈ and Mg₂Al₄Si₅O₁₈ due to the dissolution of MgAl₂O₄ substrate. The optimal flexural strength of 181–189 MPa was obtained when the joining temperature and cooling rate were 1300–1350 °C and 15 °C/min respectively. Moreover, the in-line transmittance of the joint at 1000 nm was 82.1%, which was slightly lower than that of MgAl₂O₄ ceramic (85.6%).     

Preparation,characterisation, and growth mechanism of mesoporous petal-like MgAl2O4 spinel

Petal-like MgAl₂O₄ spinel was successfully prepared using a novel inorganic salt-assisted nonhydrolytic sol-gel method without a template and was employed as absorbent in the removal of the Congo red (CR). The effects of the inorganic salt type, heat-treatment temperature, and dwelling time on the morphology and phase composition of the petal-like MgAl₂O₄ spinel were investigated systematically. Results indicated that when Na₂MoO₄ was employed as the salt and the heat-treatment temperature and dwelling time were 600 °C and 5 h, respectively, the as-obtained petal-like MgAl₂O₄ spinel exhibited a highly uniform morphology with a thickness of 19–23 nm and a length of 240–280 nm. The N₂ adsorption-desorption results revealed that the petal-like MgAl₂O₄ exhibited a large BET specific surface area of 161 m²g^-1 with a pore volume of 0.24 cm³g^-1. The growth mechanism of the petal-like MgAl₂O₄ is believed to be the formation of a two-dimensional layered network structure by the coordination between the condensation product of the magnesium aluminium bimetallic alkoxides and the ions in the salt. The as-prepared MgAl₂O₄ petal exhibited an effective adsorption capacity toward anionic dyes CR. The maximum adsorption capacity of CR onto the mesoporous MgAl₂O₄ petal was found to be 572.01 mg/g, it is showed the petal-like MgAl₂O₄ exhibit huge potential of application in the field of environmental remediation.     

Preparation and crystallite growth measurement of active magnesium aluminate spinel

MgAl₂O₄ was prepared by cocrystallizing and decomposing Al(NO₃)₃.9H₂O and Mg(NO₃)₂.6H₂O mixture. The crystallite growth of the resulting powder was studied in the temperature range 500 – 1000 °C. It was found that the equation governing the process is D² – D²₀ = KT. Two activation energies for crystallite growth were obtained, 22 kcal and 44 kcal for the temperature ranges 500 – 785 °C and 785 – 1000 °C respectively. It was noted that rapid increase in crystallite size occurred on soaking at a temperature > 800 °C.     

Effect of heat treatment conditions on the growth of MgAl2O4 nanoparticles obtained by sol-gel method

MgAl₂O₄ nanoparticles (NPs) were prepared by sol–gel method using aluminium nitrate, magnesium nitrate and citric acid as starting materials, phenolic formaldehyde resin and carbon black as additives. Growth of MgAl₂O₄ NPs in different heat treatment conditions (temperature, atmosphere, carbon additives and in Al₂O₃-C system) was investigated. MgAl₂O₄ NPs were formed at 600 °C in air atmosphere with serious agglomeration of nanoparticles having diameter of approximate 30 nm. The size of MgAl₂O₄ NPs increased greatly from 40 to 50 nm to several hundreds of nanometres as the temperature was raised from 800 °C to 1400 °C. Partial sintering of NPs was observed upon heating at temperatures higher than 1200 °C in air. In reducing atmosphere, the size of MgAl₂O₄ NPs (about 30–50 nm) changed slightly with increasing temperature. This was attributed to the dispersion of carbon inclusions in the MgAl₂O₄ grain boundaries, inducing a steric hindrance effect and inhibiting the growth of particles. MgAl₂O₄ NPs (30–50 nm) in the Al₂O₃-C system were in-situ formed at high temperatures with the use of dried precursor gels. MgAl₂O₄ NPs can contribute to improving the thermal shock resistance of Al₂O₃-C materials.     

Thermochemistry of Barium Hollandites

Barium hollandites, a family of framework titanates that can potentially be used for the immobilization of short‐lived fission products (especially ¹³⁷Cs) in radioactive wastes, have been investigated by high‐temperature oxide melt solution calorimetry using 2PbO·B₂O₃ solvent at 702°C. The enthalpies of formation from constituent oxides show increasing energetic stability of the hollandite phase as Ti⁴⁺ is substituted by Mg²⁺, Al³⁺, and Fe³⁺, in that order. In general, the thermodynamic stability increases with decreasing average cation radius in the β sites, and when the tolerance factor approaches one. The Al‐ and Fe‐hollandites are more stable than phase assemblages containing BaTiO₃ perovskite and Al/Fe/Ti oxides, whereas Mg‐hollandite is less stable than the corresponding assemblage of BaTiO₃ perovskite, MgTiO₃ ilmenite, and TiO₂. This instability makes Mg‐hollandite a less suitable host for fission products. Hollandite phase formation during metal citrate combustion synthesis depends more on thermodynamic stability and phase chemistry than on the annealing temperature.     

Effect of the Mg/Al Atomic Ratio of Ni‐Mg‐Al Catalysts for the Hydrodealkylation of 1,2,4‐Trimethylbenzene

The hydrodealkylation of 1,2,4‐trimethylbenzene (1,2,4‐TMB) to benzene, toluene and xylenes (BTX) was investigated on Ni‐Mg‐Al catalysts prepared by the coprecipitation method. The catalytic performances of these catalysts were considerably influenced by the Mg content of the catalyst. The catalysts were characterized via X‐ray diffraction, H₂‐temperature‐programmed reduction, NH₃‐temperature‐programmed desorption (TPD), CO₂‐TPD, and Fourier transform infrared spectroscopy. The results demonstrated that the appropriate amount of Mg species significantly affected the structural properties and caused the Ni nanoparticles to become highly dispersed. The higher activity of the catalysts might be ascribed to the homogenous distribution of the Ni nanoparticles, and the synergetic effects between Ni⁰, NiAl₂O₄ and MgAl₂O₄ were the key factor for obtaining the BTX.     

Interfacial Reactions Between Anorthite (CaAl2Si2O8) and Al 7075 Alloy at 850°C and 1150°C

The present work reports an investigation of the interactions of Al 7075 alloy and anorthite at 850°C (150 h) and 1150°C (24 h). Transmission electron microscopy, electron probe microanalysis, X‐ray diffraction, and scanning electron microscopy coupled with energy‐dispersive spectroscopy were used to identify the mineralogical and microstructural changes at the metal–ceramic interface. At 850°C, the phase formation mechanisms were (a) Si⁴⁺–Al³⁺ interdiffusion between the Al alloy and anorthite to form calcium dialuminate (CA₂) and Ca²⁺–Mg²⁺ interdiffusion between the Al alloy and calcium dialuminate to form spinel. At 1150°C, spinel + Al₂O₃ and calcium hexaluminate (CA₆) + CA₂ were the major and minor phase mixtures, respectively in the corroded area. A thin layer of calcium monoaluminate (CA), gehlenite, and Si was present in the immediate vicinity of anorthite. The early stages of corrosion at 1150°C and 850°C were identical. However, due to thickening of the corroded region (viz., spinel formation) and enhanced evaporation of Mg at the higher temperature, the interdiffusion path evolves from Si⁴⁺–Al³⁺ + Ca²⁺–Mg²⁺ to Si⁴⁺–Al³⁺ + Ca²⁺–Al³⁺, thus establishing the following phase evolution path at the interface:      

Ceramic matrix composite production by directed melt oxidation of pure aluminium metal using spinel dopants

Abstract

The production of Al₂O₃ matrix composites by directed melt oxidation of pure Al externally doped with spinel type dopants has been investigated. The presence of any one of MgAl₂O₄ , LiAlO₂, and ZnAl₂O₄ resulted in oxide growths in a similar fashion to the growths produced using elemental Mg, Li, and Zn. Rapid growth was achieved at 1180°C with MgAl₂O₄ and at 900°C with LiAlO₂ . The growth rates at 1180°C of the samples doped with ZnAl₂O₄ were less rapid than the growth rates of the samples doped with MgAl₂O₄ . The fact that growth is initiated by mixed oxide spinel dopants is further evidence in support of the cyclic reaction sequences that have been proposed for directed melt oxidation.     

Enhanced oxidation resistance of low-carbon MgO–C refractories with Al3BC3–Al antioxidants: A synergistic effect

The synergistic effects of Al₃BC₃–Al antioxidants on optimizing the oxidation resistance of low-carbon MgO–C refractories were investigated. The results indicated that the oxidation index and rate constant of low-carbon MgO–C refractories with optimized Al₃BC₃–Al additions were 13% and 1.10 × 10⁻⁴ cm² min⁻¹ at 1400°C for 3 h, respectively, which is much lower than that of Al or Al₃BC₃ containing ones. Single Al₃BC₃ is not a suitable antioxidant for low-carbon MgO–C refractories; however, if Al₃BC₃ was initially protected and Al reacted as the antioxidant, enhanced oxidation resistance at high temperature can be achieved. The formation of dense MgO–MgAl₂O₄–Mg₃B₂O₆ layer contributed to superior oxidation resistance, and the temperature for the generation of this layer was as low as 1100°C due to liquid and vapor phase–assisted reactions with Al₃BC₃–Al. Furthermore, a self-repairing function was achieved at 1600°C with the combination of Al₃BC₃–Al additions in spite of the faster oxidation rate.     

Characterization and mechanisms of the phase's formation evolution in sol-gel derived mullite/cordierite composite

In this work, mullite/cordierite precursor powder was prepared through a technology of low-temperature synthesis by using the sol-gel process, tetraethyl orthosilicate (TEOS) as a source of silicon oxide SiO₂, and aluminum nitrate nonahydrate Al (NO₃)₃.9H₂O as a source of aluminum oxide (Al₂O₃) and magnesium nitrate hexahydrate Mg (NO₃)₂.6H₂O as a source of magnesium oxide MgO was used as raw materials to synthesize mullite/cordierite precursor gel with a concentration (sample containing 50 wt% of cordierite and 50 wt% of mullite) and named as (MC50). The objective of this study is to find a suitable kinetic model to study the phases and the mechanisms of their formation in mixtures, with the prediction of the system's behavior under selected thermal conditions, including finding the kinetic and thermodynamic media that describe these interactions. To follow and characterize the crystalline phases and their transformation as a function of temperature utilizing differential thermal analysis (DTA), Dilatometry (DIL), and powder X-ray diffraction (XRD). The results show that the crystallization process occurred in the temperature interval between (900–1350) °C. In the temperature range of (900–1000) °C, spinels between Al–Si and Al–Mg with the chemical formulas (Al₄Si₃O₁₂ and MgAl₂O₄) were formed. When the thermal treatment temperature increases from (1000–1100) °C, mullite is produced. As the temperature increases, the amount of Mg–Al spinel decreases to form amorphous silica, and μ-cordierite has appeared at 1250 °C. With an increase in temperature up to 1350 °C, α-cordierite appeared as a stable phase. The reason for this is the presence of the spinel (Al–Mg) phase that helped it form.To determine the reaction kinetics of these transformations at high temperatures, the mixture 50/50 mullite/cordierite was selected to study its kinetics. The activation energy values (Ea/Tm) (Tm is the maximum temperature of the transformation, i.e., the maximum peak temperature is not related to the crystallization fraction α) calculated by Ozawa, Boswell, and Kissinger methods are in good agreement with the evident activation energy (Eα/Tα) (Tα is the degree of the heat of transformation in terms of crystallization fraction α changes from 0<α < 1) calculated using the KAS and FWO methods.For the purpose of calculating the interaction model and finding the media that determine the interaction model based on the experimental data, Malék's methodology method was used. The best kinetic model is the Šesták - Berggren model to describe the reaction process to form spinel, mullite, and α-cordierite. From the SB model, the equations Kinetics and all kinetic parameters (n, m, ln(k₀)) that describe the kinetics of the reactions and mechanisms of formation of spinel, mullite, and α-cordierite in the mixture are, respectively, (2.14, 0.023, 65.21), (1.62, 0.1232, 81.76), and (1.41, 0.2859, 91.13). While the values of Gibbs free energy ΔG#, enthalpy ΔH#, and entropy ΔS# were as follows: 407.254 kJ mol⁻¹, 976.756 kJ mol⁻¹ and 415.561 J mol⁻¹K⁻¹ for Mullite formation, and 471.64 kJ mol⁻¹, 1255.16 kJ.mol-1 and 491.75 J mol⁻¹K⁻¹ for the formation of α-cordierite.Comparison of simulation curves with experimental data obtained at different temperatures gives good agreement with the thermal analysis data (Experimental), which indicates that the Model of Šestak − Berggren, is the best suitable kinetic model for studying and describing the reaction technique for MC50 prepared by the sol-gel method.