AHCEN Keziz
كزيز أحسن
ahcen.keziz@univ-msila.dz
0
- Departement of Physics
- Faculty of Sciences
- Grade PHd
About Me
Sciences de la Matière
Filiere
Physique
Applied Physics
Location
Msila, Msila
Msila, ALGERIA
Code RFIDE- 1992-11-14 00:00:00
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AHCEN Keziz birthday
- 2023-10-27
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2023-10-27
Mechanism and characterization of forsterite (Mg2SiO4) formation obtained by the sol-gel method
In this work, forsterite precursor powder was prepared through a technology of low-temperature synthesis by using the sol-gel process, tetraethyl orthosilicate, and Mg(NO3)2.6H2O were used as raw materials to synthesize forsterite. To pursue and characterize the crystalline phases and their transformation as a function of temperature, Thermogravimetry, differential thermal analysis, X-ray diffraction and Fourier-transform infrared spectroscopy was used. The results showed that the crystallization process occurred in the temperature range of 650 to 1100 °C. Forsterite, a mineral with the chemical formula Mg2SiO4, was formed in the 650–800 °C temperature range. When the temperature is increased from 800 °C to 1100 °C, forsterite becomes more crystallized. The obtained results agree with the X-ray diffraction analyses that approve that there is just one phase (forsterite). The activation energy values (Ea/Tm) calculated by Ozawa, Boswell, and Kissinger methods are in good agreement with the activation energy (Eα/Tα) calculated using the KAS and FWO methods. So as to determine the interaction model and find the parameters that determine the interaction model based on the experimental data, Malék's methodology method was used. The Šesták - Berggren model is the most appropriate kinetic model to describe the reaction process to form forsterite. 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 forsterite are, respectively, 1.02 , 0.36, and 26.8. While the values of Gibbs free energy #ΔG, enthalpy #ΔH, and entropy #ΔS were as follows: 294.871 kJ/mol, 252.938 kJ/mol, and -40.5 J/mol.K for forsterite formation.
Citation
MENAD Heraiz , Ahcen Keziz , ,(2023-10-27), Mechanism and characterization of forsterite (Mg2SiO4) formation obtained by the sol-gel method,10th INTERNATIONAL CONFERENCE ON COMPUTATIONAL AND EXPERIMENTAL SCIENCE AND ENGINEERING (ICCESEN-2023),ANTALYA-TURKEY
- 2023-09-09
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2023-09-09
Structural, morphological, dielectric properties, impedance spectroscopy and electrical modulus of sintered Al6Si2O13–Mg2Al4Si5O18 composite for electronic applications
In this study, the sol-gel method of low-temperature synthesis was utilized to create mullite/cordierite precursor powder. The materials (TEOS) Si(C2H5O)4, Al(NO3)3.9H2O and Mg(NO3)2 were utilized as source of SiO2, Al2O3, and MgO oxides respectively in order to create mullite/cordierite precursor gel with various concentrations and designations (MC00, MC10, MC20, MC30, MC40, and MC50). Crystalline phases were seen and described using scanning electron microscopy (SEM) and powder X-ray diffraction (XRD). After the powder was formed at 1600 ◦C for an hour, its sintering was looked at. For all mixes, as the cordierite concentration rises, the bulk density rises and the open porosity decreases. The existence of a vitreous phase may be the cause of the rise in bulk density and reduction in open porosity seen with rising temperatures. The dielectric characteristics of the samples have been examined at room temperature; the relative dielectric constant (εr), loss tangent (tan δ), and dielectric characteristics were assessed at frequencies of 0.1 Hz, 1, 10, 100, and 1000 kHz. At 1 kHz, the relative dielectric constant values are closest to those of mullite (εr = ~5 to ~ 6), and c at 1 kHz. On the other hand, the lowest dielectric losses were observed (tan δ from ~0.06 to ~ 0.04). The Electrical properties, electrical resistivity, AC conductivity, impedance spectroscopy, electrical modulus, and the relative quality factor (QF) of pure mullite and mullite/cordierite composite sintered at 1600 ◦C for 1 h (MCyy) samples were investigated as a function of cordierite content at varied frequencies (0.01 Hz, 1 kHz, 100 kHz, and 1000 kHz). The hardness (HV) and coefficient of thermal expansion (CTE) of the composite material that underwent sintering at a temperature of 1600 ◦C were determined by the use of a hardness tester and a dilatometer, respectively. The rise in temperature, coupled with an equal quantity of cordierite, resulted in an elevation of the apparent density and a reduction in the open porosity. In the case of the specimen subjected to sintering at a temperature of 1600 ◦C, the introduction of cordierite content in the range of 0–40% resulted in an observed rise in HV value from 9.15 to 12.99 GPa. However, a further increase in cordierite content to 50% led to a decrease in HV value to 10.99 GPa. Nevertheless, the CTE value throughout the temperature range of 50–1200 ◦C exhibited a consistent decline, ranging from 5.37 × 10 6 to 2.32 × 10 6 K 1. Notably, the composite material consisting of 50 wt% cordierite had elevated HV and the most minimal CTE value.
Citation
Ahcen Keziz , MENAD Heraiz , Foudil SAHNOUNE , Mohammed Rasheed, Aya Latif, , (2023-09-09), Structural, morphological, dielectric properties, impedance spectroscopy and electrical modulus of sintered Al6Si2O13–Mg2Al4Si5O18 composite for electronic applications, Ceramics International, Vol:49, Issue:23, pages:37423-37434, ELSEVIER SCI LTD
- 2023-03-10
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2023-03-10
Dense, Hard, and Thermally Stable Al6Si2O13–Mg2Al4Si5O18 Composite Material for Silicon Substrate Applications
One of the key problems to overcome, in the development of electronic substrates, is that of thermal distortion because of thermal mismatch between silicon and the substrate. The aim of this work is to design a mullite-cordierite composite material, with coefcient of thermal expansion tailored to silicon substrate applications. Dense, hard, and thermally stable Al6Si2O13–Mg2Al4Si5O18 composite was produced by sintering amorphous precursor powder synthesized through the sol–gel method. Si(C2H5O)4, Al(NO3)3.9H2O, and Mg(NO3)2.6H2O were used, as source of SiO2, Al2O3, and MgO oxides, respectively, to prepare mullite-cordierite precursor powders. Fourier-Transform Infrared spectroscopy (FTIR), Thermogravimetry (TG), Dilatometry, Diferential Thermal Analysis (DTA), and X-ray powder Difraction (XRD) methods were used to characterize the synthesized amorphous powder and its crystallization. The microstructure of specimens sintered at 1600 °C for 1 h was analyzed using a scanning electron microscope (SEM). The hardness (HV) and coefcient of thermal expansion (CTE) of the composite sintered at 1600 °C were measured by using a hardness tester and a dilatometer, respectively. The results show the increase in density and decrease in open porosity with the increase in temperature and equivalent amount of cordierite. For specimens sintered at 1600 °C, the increase in cordierite content from 0 to 40 wt.% increased the HV from 9.18 to 13.08 GPa; a further increase to 50 wt.% decreased it to 11.15 GPa. Sample containing 40 wt.% cordierite had the highest value of hardness (HV=13.08 GPa), representing an increase of 42.48% with respect to monolithic mullite. The CTE of the composites (in the range 50–1000 °C) showed continuous decrease from 5.23× 10–6 to 2.26× 10–6 K−1 with the increase in cordierite content from 0 to 50%. Sample containing 50 wt.% cordierite displayed the lowest thermal expansion (CTE of 2.26× 10−6 K−1), representing a decrease of 56.78% with respect to monolithic mullite.
Citation
Ahcen Keziz , MENAD Heraiz , Foudil SAHNOUNE , KHADIDJA Laziri , Redaoui El Djida, Saheb Nouari, , (2023-03-10), Dense, Hard, and Thermally Stable Al6Si2O13–Mg2Al4Si5O18 Composite Material for Silicon Substrate Applications, Silicon, Vol:15, Issue:4, pages:12, springer
- 2023-01-08
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2023-01-08
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, Mal´ek’s methodology method was used. The best kinetic model is the ˇSest´ak - 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 ˇSestak Berggren, is the best suitable kinetic model for studying and describing the reaction technique for MC50 prepared by the solgel method.
Citation
Ahcen Keziz , MENAD Heraiz , Foudil SAHNOUNE , Mohammed Rasheed, , (2023-01-08), Characterization and mechanisms of the phase’s formation evolution in sol-gel derived mullite/cordierite composite, Ceramics International, Vol:49, Issue:20, pages:32989–33003, ELSEVIER SCI LTD
- 2022
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2022
Preparation of ceramic composite powders by By the sol-gel Method
Preparation of ceramic composite powders by By the sol-gel Method
Citation
Ahcen Keziz , MENAD Heraiz , ,(2022), Preparation of ceramic composite powders by By the sol-gel Method,Séminaire international sur la chimie organique et pharmaceutique (ICPOC’ 2022) , 11 et 12 octobre 2022,,université de 20 Aout 1955- Skikda
- 2022
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2022
CHARACTERIZATION OF CORDIERITE/MULLITE COMPOSITES PREPARED BY SOL-GEL TECHNIQUE
CHARACTERIZATION OF CORDIERITE/MULLITE COMPOSITES PREPARED BY SOL-GEL TECHNIQUE
Citation
Ahcen Keziz , MENAD Heraiz , ,(2022), CHARACTERIZATION OF CORDIERITE/MULLITE COMPOSITES PREPARED BY SOL-GEL TECHNIQUE,THE 1ST INTERNATIONAL CONFERENCE ON RENEWABLE MATERIALS AND ENERGIES ICRME2022 October 26-27, 2022, ”,OUARGLA-ALGERIA