HOCINE Belhouchet

HAMMOU Zeyneb

Influence of additions on the preparation of yeelimite from natural phosphate.

Houichi elkamila

تحضير اليليميت إنطلاقا من الفوسفات الطبيعي وخبث الألمنيوم المستخرج من مصنع (ALGAL Plus)

DJOUALLAH Samira

Influence des additions sur le frittage de phosphate naturel

REFICE Elhamdi

Influence de l'ajout de l'ajout de la sphalérite sur la préparation de yeelimite à partir du phosphate naturel

KHERIFI Djelel

Development of phosphocalcic bioceramics from natural phosphate

طيبي حياة

الخزفيات الشفافة : المواد، طرق و تقنيات التحضير ، خصائص و تطبيقات

KENZOUR Abdelghani

Elaboration et caractérisation d'un phosphate tricalcique à partir du kaolin et de phosphate naturel

HAMMOU Zeyneb

Effet des additifs sur les propriétés de yeelimite élaborée à partir de matériaux locaux

Mokhtari Afaf

تحضير و دراسة مواد خزفية إنطلاقا من الفوسفات الطبيعي و مسحوق الألمنيوم

In this work, we studied the mechanism and the kinetic parameters of the thermal oxidation of aluminum slag using the differential thermogravimetry technique under non-isothermal conditions. The experiments were conducted between room temperature and1300◦C at heating rates of 5, 10, and 20◦C/min. The obtained differential thermogravimetry curves clearly show two distinct mass gains. The first mass gain is due to the oxidation of aluminium in the solid state. Among the32 types of differential equations describing non isothermal kinetics, we found that the most suitable mechanism is(A3/2 : g(x) = [−ln(1−x)]2/3), also known as the Avrami-Erofeev equation of order2/3.The activation energy (Ea) for the oxidation of aluminium in the solid state was determined to be 260 kJ/mol. The second mass gain corresponds to the oxidation of aluminum in the liquid state. Under the applied conditions, the oxidation process follows a second-order reaction mechanism (F2 : g(x) = (1−x)−1−1). The activation energy(Ea) for the oxidation of aluminum in the liquid state was determined to be around 430kJ/mol. The parameter m is equal to 1.85 for the formation of γ −alumina in the aluminum slag. This value is close to 2, indicating a two-dimensional growth of γ −alumina crystals. On the other hand, m is equal to 2.65 for the formation of α−alumina in the aluminum slag, which is close to 3,suggesting a three-dimensional growth of α−alumina crystals. The morphological growth parameter n is approximately 2 for the crystallization of γ−alumina and around 2.5 for the crystallization of α−alumina. These results indicate that bulk nucleation is the dominant mechanism in the crystallization of both γ−alumina and α−alumina, and that crystal growth is diffusion-controlled.

Citation

Hocine BELHOUCHET , ,(2025-09-03), Mechanism and Kinetic Parameters of the Thermal Oxidation of Aluminum Slag by Thermogravimetric Analysis,9th International Conference of Mathematical Sciences (ICMS 2025),Maltepe University, Istanbul, Turkey

This study investigates the development of compounds based on ye'elimite-spinel, which incorporates magnesium oxide (MgO) and fluorapatite. Utilizing natural fluorapatite as a raw material not only provides a cost-effective source of calcium oxide but also reduces the dependency on limestone, thereby decreasing CO2 emissions linked to decarbonization. This research presents an in-depth analysis of the sintering behavior and phase transformations of ceramic materials. Techniques such as X-Ray diffraction (XRD), Rietveld method, SEM-EDS, FT-IR, and TG/DTG were employed to explore the effects of temperature (ranging from 1000 to 1500 °C) and varying MgO content (0–6 wt%) on phase formation, including fluorapatite, ye'elimite, spinel, and other high-temperature phases like hibonite, beta-tricalcium phosphate, and grossite. These findings indicate that increasing MgO content promotes the formation of spinel while stabilizing ye'elimite at higher temperatures. The results provide valuable insights for optimizing the composition and thermal properties of these composites for high-temperature applications, such as cements, refractories, and advanced ceramics.

Citation

Hocine BELHOUCHET , , (2025-07-01), The influence of magnesium oxide on natural fluorapatite decomposition during the preparation of ye'elimite-spinel based multi-phase composites, Ceramics International‏, Vol:51, Issue:18, pages:26507-26518, Elsevier Ltd

The nucleation and growth kinetics of mullite crystal structure prepared from Algerian natural phosphate (NP) and kaolin materials were studied by differential thermal analysis (DTA) and X-ray diffraction (XRD). The XRD patterns showed that mullite, hydroxyapatite and anorthite were the main crystal structures present in mixtures. From DTA results, several thermal characteristics including the crystallization peak temperature, activation energies, were calculated. The DTA results showed that the characteristics temperature and activation energies were reduced when the NP content was increased at the expense of kaolin material. Bulk crystallization was seen in samples with low/moderate and high NP amounts, respectively, with a fixed () and growing ( and ) number of nuclei. As a result, it is possible to produce the mullite phase using Algerian kaolin raw material and natural phosphate that can be added as a structural modifier of the growth process.

Citation

Hocine BELHOUCHET , , (2025-04-21), Unveiling the nucleation and growth kinetics of mullite crystals in kaolin and natural phosphate compounds, Journal of Thermal Analysis and Calorimetry, Vol:150, Issue:, pages:7425–7437, Springer

In the research described in this paper, we prepared low-cost multiphase composites based on calcium sulfoaluminate (also known as ye’elimite) and fluorapatite. By utilizing the CaO originally present in fluorapatite, the sintering densification of these composites was enhanced. The influence of varying the SiO2 content (0–5.4 wt.%) on the reactive sintering of fluorapatite, bauxite, and gypsum was investigated. Incorporating quartz led to the formation of various compositions, including calcium hexaluminate, fluorapatite, ye’elimite, and gehlenite. Quantitative phase analysis, conducted using the Rietveld method via Profex software at various sintering temperatures, demonstrated a relationship between quartz content and the preferential formation of gehlenite over ye’elimite within the 1300–1350 °C range. Additionally, the microstructure of the composites was significantly modified by quartz addition, leading to the development of hexagonal and circular grains after heat treatment at 1400 °C.

Citation

ZEYNEB Hammou , Hocine BELHOUCHET , , (2024-11-18), The effect of quartz on natural fluorapatite decomposition during the preparation of calcium sulfoaluminate‑based multiphase composites, Materials and Structures, Vol:57, Issue:234, pages:15, Springer Nature Link

This study delves into the development of porcelain using local raw materials, focusing on insulator contamination as a crucial factor contributing to flashover and security issues in high-voltage power systems. To alleviate this problem, the introduction of nano-TiO2 coating is proposed as a means to enhance the properties of porcelain insulators. This porcelain composition was formulated using a blend of kaolin, quartz, feldspar, and recycled waste glass. The resulting specimens underwent characterization through X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) analyses. The research aims to evaluate the relationship between an insulator’s electrical performance and critical flashover voltage in the presence of nano-TiO2 coating, based on experimental results. An artificial contamination test was conducted, and characterization techniques such as Atomic Force Microscopy (AFM) were employed to analyze surface, morphology, and thickness. Raman spectroscopy was utilized to analyze the TiO2-coated surface. Electrical tests were performed on both coated and uncoated samples to assess the impact of the titanium dioxide film on electrical properties. The TiO₂ coating significantly enhances the reliability of porcelain insulators by increasing flashover voltage, reducing leakage current, and improving both dielectric strength and insulation resistance. Furthermore, the Finite Element Method (FEM) was applied to analyze the effects of coating on the porcelain insulator’s electrical performance. The results underscored the improvement in electrical properties of the studied porcelain, which can be attributed to the isolating properties of the nanoparticles. The combination of experimental and simulation results provides valuable insights into the influence of TiO2 thin film and its role in enhancing the electrical properties of porcelain.

Citation

Khaled BELHOUCHET , Hocine BELHOUCHET , abderrahim.zemmit@unive-msila.dz, Abdelhafid Bayadi, Maximina Romero, , (2024-10-26), Nano‑TiO2 coating for improved electrical properties of outdoor high‑voltage porcelain insulators, Journal of Materials Science: Materials in Electronics, Vol:35, Issue:1971, pages:18, Springer

In this work, we studied the kinetics of spinel (Al-Si) crystallization from Algerian kaolinite (DD2) in different mixtures under non-isothermal conditions using DTA. Although many mathematical equations were proposed for the calculation, the Johnson-Mehl-Avrami (JMA) equation and Kissinger method are the most commonly used. Four compositions marked as N00, G10, G20, and G30, corresponding to 0, 10, 20, and 30 wt% of glass, were fabricated and studied. Recycled waste glass was added to kaolin and quartz to partially replace potash feldspar for the prepared white porcelain. The DTA conducted at heating rates of 2, 5, 10, and 15 °C/min showed an exothermic peak in all compositions at about 950 °C associated with spinel crystallization. This crystallization temperature decreased slightly with increasing glass content. The activation energies measured from non-isothermal treatments for four compositions: 00, 10, 20, and 30 wt% of glass, were, 694, 684, 615, and 498 kJ/mol, respectively. The activation energy decreases with the increase in glass percentage. The n values (Avrami parameter) obtained for all compositions are about 2, the spinel crystallization of these composites is followed by three-dimensional growth (controlled by diffusion).

Citation

Hocine BELHOUCHET , ,(2024-07-19), International Conference on Applied Analysis and Mathematical Modeling (ICAAMM 2024),International Conference on Applied Analysis and Mathematical Modeling (ICAAMM 2024),Isranbul (turkey)

This study evaluates Algerian kaolin (Djebel Debbagh (DD1) and Tamazart (KT2)) as potential substitutes for commercial kaolin (Lab) in the production of mullite-based ceramics. Three compositions were prepared by incorporating the appropriate percentage of alumina to each calcined kaolin to achieve stoichiometric mullite precursors. The phase evolution of individual kaolin powders, as well as their mixtures with alumina, depends strongly on the calcination temperature and kaolin impurities. The differential scanning calorimetry combined with thermogravimetric analysis (TGA) showed lower secondary mullite formation temperature for the KT2-based mixture. However, X-ray diffraction revealed a complete mullitization in DD1 mixture. The K2O hindered cristobalite formation and reduced secondary mullite formation rate. Microstructure analysis showed lath-shaped primary mullite and equi-axed secondary mullite particles. After sintering at 1600◦C, The KT2-based sample (M3) exhibited higher density (3.013 g/cm3) and hardness (9.9 GPa), whereas the DD2-based sample (M2) showed moderate densification (2.91 g/cm3) and higher flexural strength (159.42 MPa). Impurities (mainly Fe2O3, and K2O) promoted liquid phase sintering, resulting in greater densification in M3, whereas M2 showed more homogeneous microstructure, refined grains, and lower glassy phase content, contributing to enhanced strength.

Citation

Hocine BELHOUCHET , , (2024-06-17), Investigations on kaolin mixtures: Impact on mullite formation kinetics andmicrostructure evolution, International Journal of Applied Ceramic Technology, Vol:21, Issue:6, pages:3950-3966, Wiley Online Library

بسم الله الرحمـن الرحيـم الحمد لله رب العالمين و الصلاة و السلام على أشرف المرسلين سيدنا محمد (صلى الله عليه و سلم) و على آله و صحبه أجمعين. إن التحدي الحقيقي الذي يواجهنا في وقتنا الحاضر هو قضية التعريب التي أخذت أبعاداً أهم وأعمق فقد ابتعدت اللغة العربية خلال الاحتلال الفرنسي عن الكثير من مواقعها، وفُرضت الفرنسية لغة أساسية للتعليم والإدارة والاقتصاد، بدعوى أنها لغة العلم و التطور. غير أن الأبحاث و الدراسات الحديثة أكدت بأن قدرة استيعاب الفرد بلغته الأم أفضل بكثير ، لأن الإبداع و الابتكار و حتى التفكير مرتبطون بشكل أساسي باللغة القومية لأي أمة. و حتى ندحض تلك الأقاويل بأن اللغة العربية قاصرة أمام اللغات الأخرى و أنها غير قادرة على استيعاب تطورات العصر و خاصة في مجال التعليم العالي بكل فروعه العلمية و إنطلاقا من مقولة : "لم تتطور أمة بغير لغتها"، كان هذا العمل المتواضع و الذي يتعلق بمقياس العوازل و الإقتران الفيزيائي الذي يدرس لطلبة السنة الثانية ماستر فيزياء المواد بجامعة محمد بوضياف بالمسيلة. تم وضع هذه المطبوعة بشكل ملائم للطلبة الجامعيين الذين يهتمون بدراسة المواد و خاصة الفيزيائيين منهم، كما تم اختيار محتوياتها لكي تؤكد الطرق الأساسية لدراسة الخصائص العزلية للمواد واعتماد هذه الخصائص على التركيب البلوري و البنيوي للمادة، حيث تم عرضها بشكل مبسط ليسهل تناول مادتها العلمية ولتكون مرجعا مفيدا لطلاب الفيزياء والكيمياء بكلية العلوم و بعض اقسام كلية التكنولوجيا.

Citation

HocineBELHOUCHET , ,(2023-10-22); العوازل و الإقتران الفيزيائ,Université de M'sila,

Due to the increase in demand for cement in recent decades, the research has tended to the eco-cements such as Yeelimite, which is distinguished from other cements by its low carbon emissions. Calcium sulfoaluminate (CSA) cement or yeelimite belongs to the family of cements that have certain advantages over Portland cement (PC): low sintering temperature, reduced CO2 emissions, fast hardening and low shrinkage. The main components of CSA cement are yeelimite (C4A3S in cement notation where C=CaO, A=Al2O3, S=SO3). CSA cement has been used in many applications, such as bridge decks, pipes, concrete, etc. The objective of this work is the preparation and characterization of Yeelimite-based materials from local materials (natural phosphate from Djebel el-Onk), then the study of the physico-chemical and mechanical properties of the prepared materials. On the other hand, different experimental techniques, including density, porosity, shrinkage, Vickers hardness, XRD were used to analyse the formation and transformation of various phases at different temperatures. Through these results, we lighted the possibility of preparing the yeelimite from local materials (natural phosphate). Key-words: Yeelimite, Portland cement, Natural phosphate, Low CO2 emissions.

Citation

ZEYNEB Hammou , Hocine BELHOUCHET , ,(2022), Preparation and characterization of yeelimite from local materials,The first International Seminar on Materials Synthesis and Environmental Monitoring,university of kasdi merbah ouargla

In this work, the sintering behaviour of fluorapatite (FAp)–silicate composites prepared by mixing variable amounts of natural quartz (2.5 wt% to 20 wt%) and FAp was studied. The composites were pressureless sintered in air at temperatures from 1000 °C to 1350 °C. The effects of temperatures on the densification, phase formation, chemical bonding and Vickers hardness of the composites were evaluated. All the samples exhibited mixed phase, comprising FAp and francolite as the major constituents along with some minor phases of cristobalite, wollastonite, dicalcium silicate and/or whitlockite dependent on the quartz content and sintering temperature. The composite containing 2.5 wt% quartz exhibited the best sintering properties. The highest bulk density of 3 g/cm3 and a Vickers hardness of >4.2 GPa were obtained for the 2.5 wt% quartz–FAp composite when sintered at 1100 °C. The addition of quartz was found to alter the microstructure of the composites, where it exhibited a rod-like morphology when sintered at 1000 °C and a regular rounded grain structure when sintered at 1350 °C. A wetted grain surface was observed for composites containing high quartz content and was believed to be associated with a transient liquid phase sintering.

Citation

Hocine BELHOUCHET , , (2021), Sintering behaviour of fluorapatite–silicate composites produced from natural fluorapatite and quartz, Ceramics International, Vol:47, Issue:12, pages:16483-16490, Elsevier

In this investigation, we studied the reaction-sintering between fluorapatite and alumina using natural phosphate and boehmite. The addition of alumina, resulting from the boehmite transitions, to the fluorapatite (FAp) has been carried out to obtain various composites based on FAp, yeelemite, mayenite, grossite (CA2), hibonite (CA6) and β-TCP. Several samples were prepared by varying the boehmite (AlOOH) amount to obtain six compositions which contain after sintering: 5, 10, 15, 20, 25 and 30 wt% of Al2O3. After ball-milling for 5 h, all compositions were sintered in the air for 2 h at different temperatures ranging from 1000 to 1500 °C. The reactions and phase transformations between fluorapatite and boehmite were studied and characterized by DTA/TG, XRD, FT-IR, apparent density and open porosity measurements, micro-hardness and SEM analysis. The micro-hardness and densification of the sintered body showed a marked improvement by increasing the alumina content and sintering temperature. Especially, sample containing 25% alumina exhibited the highest densification at 1400 °C (2.95 g/cm3) and excellent micro-hardness of about 6.5 ± 0.25 GPa. So the preparation of low cost composites based on fluorapatite, yeelimite and grossite from natural phosphate and alumina are feasible.

Citation

Hocine BELHOUCHET , S.Djouallah, A.Kenzour, D.Kherifi, , (2021), Sintering behavior of fluorapatite-based composites produced from natural phosphate and alumina, Ceramics International, Vol:47, Issue:3, pages:3553-3564, Elsevier

The present work focuses on the study of the effects of mechanical activation on the reaction between hydroxyapatite (HAp) and aluminum metal powder using Algerian phosphate (natural HAp) as a starting raw material. Aluminum metal powder was used to obtain reinforced (HAp) composites materials with alumina. The alumina phases result from the oxidation of aluminum powder at high temperature. The reactions and phase transformations between HAp and aluminum powder were studied using thermal techniques (DTA/TG), X-ray diffraction (in situ HTXRD and standard), infrared spectroscopy (FT-IR) and SEM analysis. After mechanical treatment for different milling time, no new phases were formed from HAp and Al after 40 h of milling at room temperature. However, all mixture powders were milled for different time showing the formation of several alumina transitions during heat treatment. The oxidation of Al powder, the formation of alumina transitions (v and j-Al2O3), a-alumina, HAp crystallization and tricalcium phosphate (b-TCP and a-TCP) formation were affected by ball milling time. After 40 h of ball milling, the aluminum was not detected at 673 K, which confirms the solid-state oxidation of aluminum at low temperatures. The results showed the formation of high amount of a-TCP at 1173 K in the samples milled for 40 h.

Citation

Hocine BELHOUCHET , Afaf Mokhtari, A Guermat, , (2019), In situ high-temperature X-ray diffraction, FT-IR and thermal analysis studies of the reaction between natural hydroxyapatite and aluminum powder, Journal of Thermal Analysis and Calorimetry, Vol:136, Issue:, pages:1515–1526, SpringerLink

tThe present study is aimed to develop porcelain from locally available raw materials. Thisporcelain was prepared from the mixture of kaolin, quartz, feldspar, and recycled wasteglass. In this work, the expensive K-feldspar was substituted by recycled waste glass derivedfrom broken car glass. The effects of recycled waste glass in partial replacement of K-feldsparfor porcelain are discussed. Experimental results showed significant effects of recycledwaste glass substitution and sintering temperature on physical properties. Furthermore,the microstructure observation indicated that the replacement of K-feldspar by the recy-cled waste glass indicates the reducing firing temperature 200◦C was achieved by 30 wt%glass addition. Moreover, experimental investigations showed excellent mechanical (micro-hardness) and insulating properties (dielectric strength) of the prepared porcelain whencompared to that of traditional porcelain insulators. The Vickers micro-hardness found anincrease with both glass addition and sintering temperature. Dielectric constant (ε), dielec-tric loss tangent (tan ı) and loss factor (ε) were measured at different frequencies. Theresults reveal that glass addition enhances the dielectric properties of the samples fired at1100◦C. Finally, the best results of phase angle were obtained ∼(−89.2◦) for this porcelain.These results prove that our prepared insulator is a dielectric capacitor.

Citation

Khaled BELHOUCHET , Hocine BELHOUCHET , A bayadi, Maximina Romero, , (2019), Improvement of mechanical and dielectric properties of porcelain insulators using economic raw materials, Boletin de la Sociedad Espanola de Ceramica y Vidrio, Vol:57, Issue:, pages:28-37, Elsevier

In this paper, we prepared by reaction sintering a hydroxyapatite /yeelimite composite from the natural phosphate of Djebel el’onk and the aluminum metal powder. The effect of aluminum addition on the sintering of natural hydroxyapatite was investigated. Hydroxyapatite (HAp) bioceramic materials have been widely applied as bone substitutes because of its excellent compatibility with the human body. The additions of aluminum to the hydroxyapatite have been carried out to improve properties of sintered HAp. By mechanical treatment, hap properties were studied according to the different milling time and the composite ceramics were sintered in air at various temperatures ranging from 1200 to 1450°C. The reactions and phase transformations between natural hydroxyapatite and aluminum metal powder were studied by various experimental techniques such as XRD and SEM. The results of the mixture of hydroxyapatite and aluminum powder showed the formation of deferent phases after high time of milling at high temperature. The addition of aluminum results the partial decomposition of hydroxyapatite at high temperature.

Citation

Hocine BELHOUCHET , Afaf Mokhtari, ,(2019), The effect of aluminum powder addition on the sintering of hydroxyapatite,Third International conference of mechanics and materials ICMM 2019,Setif, Algeria

In this work, the effects of mechanical activation on the reaction-sintering of hydroxyapatite/aluminum powder were investigated. The low mechanical properties of the hydroxyapatite have been the main problem of the extensive use of this material. The addition of alumina, resulting from the oxidation of aluminum, to the hydroxyapatite has been carried out to improve his mechanical properties. All samples were heated at different temperatures (1200-1450°C) for 2 h and characterized by apparent density, open porosity measurements, XRD and SEM analysis.

Citation

Hocine BELHOUCHET , ,(2019), Elaboration and characterization of porous hydroxyapatite materials via the reaction-sintering of phosphate and aluminium powder,Apmas 2019,Oludeniz, TURKEY

In this work, the effect of heating rate and mechanical activation on the reaction of kaolin and aluminium powder was investigated. A batch comprised of 89.5 wt%kaolin and 10.5 wt%aluminiumpowders was mixed and milled in a planetary ball-mill for 1, 5, 10, 20 and 40 h. The mixture powders were heat treated with a heating rate of 5, 10, 15, 20, 30 and 40 °C/min, respectively. After milling for 20 and 40 h, the results showed the formation of free silicon, quartz and nacrite (Al2Si2(OH)4) at room temperature. The kaolinite dehydroxylation, aluminium oxidation and the θ- to α-Al2O3 transformations are highly affected by heating rate and mechanical activation. As comparedwith the smallest heating rate, the mixtures heated with faster heating rate show the disappearance of the peak corresponding to the oxidation of aluminium and the appearance of a second peak corresponding to the formation of α-Al2O3. The intensity of the last peak increases with increasing of the heating rate and milled at lower milling time. The effects of heating rate in the reaction of kaolin and aluminium powder are attributed to the amorphization of kaolinite, the diffusion of Al3+ to form an amorphous alumina layer on the particle surface and the generation of microcracks at the particle surface of aluminium powder.

Citation

Hocine BELHOUCHET , Khaled BELHOUCHET , Toufik Sahraoui, Maximina Romero, , (2019), Influence of heating rate and mechanical activation on the reaction between kaolin and aluminium powder, Journal of the Australian Ceramic Society, Vol:55, Issue:, pages:135–144, SpringerLink

In this work, the activation energy of hydroxyapatite formation in different composites under non-isothermal conditions was determined using differential thermal analysis (DTA). Seven compositions were prepared and studied while varying the percentage of the kaolin from 20 to 80 wt.% at 10% increments. The DTA conducted at heating rates of 10, 20 and 30 K min−1 showed an exothermic peak in all composites in the region 700°C–750°C associated with hydroxyapatite formation. The activation energies measured from non-isothermal treatments for seven compositions (20, 30, 40, 50, 60, 70 and 80 mass% of kaolin) were 194, 178, 178, 209, 162, 146 and 121 kJ mol−1, respectively.

Citation

Hocine BELHOUCHET , Fateh Chouia, Toufik Sahraoui, , (2019), The non-isothermal kinetics of hydroxyapatite formation in kaolin - natural phosphate mixtures, World Journal of Environmental Research, Vol:9, Issue:, pages:1-7, /

In the present work anorthite-TCP composite ceramics was produced for the first time by the solid-state sintering process involving the mixture of local natural materials of phosphate and kaolin. Various samples were prepared by varying the kaolin content from 47 to 57 wt%. The composite ceramics were sintered in air at various temperatures ranging from 1250 °C to 1325 °C and characterized to determine the phase present, relative density, Vickers microhardness, chemical bonding of molecules and microstructural development. In general, all the samples exhibited a hybrid structure, comprising of anorthite and β-TCP as the major phases with a concomitant minor phases such as TTCP and/or gehlinite depending on the temperature and kaolin content. In addition, increasing kaolin content and sintering temperature were found to be effective in improving the densification and hardness of the sintered body. In particular, sample containing 57 wt% kaolin exhibited excellent densification at 1300 °C and 1325 °C, achieving above 97% dense bodies and highest hardness of about 6.5 ± 0.7 GPa. Microstructural investigation revealed that a dense structure was evident for these samples due mainly to enhanced particle coalescence during the liquid phase sintering, resulting in pore elimination and grain coarsening.

Citation

Hocine BELHOUCHET , , (2019), Sintering behavior of anorthite-based composite ceramics produced from natural phosphate and kaolin, Ceramics International, Vol:45, Issue:16, pages:20258-20265, sciencedirect

In order to fabricate cheaper porous hydroxyapatite/krotite composites, we worked on the opportunity to use Algerian phosphate and aluminum metal powder. Hydroxyapatite (Hap) is a bioceramics due to its similar composition to bone substitutes because of its excellent bioactive properties. However, the low mechanical properties of this material have been the major problem of the extensive use of this bioceramics. Aluminum metal powder was used to obtain reinforced hydroxyapatite composites with krotite. The alumina phases resulting from the oxidation of aluminum powder at high temperature. The reactions and phase transformations between hydroxyapatite and aluminum powder were studied using thermal techniques (DTA/TG), X-ray diffraction (standard and In-situ XRD) and infrared spectroscopy (FT-IR). All samples were heated at different temperatures and characterized by apparent density, open porosity measurements, XRD and SEM analysis. The results showed the formation of different phases at room temperature. The mixture powder milled showed the formation of different phases during heat treatment. Porosity was shown to be increased with temperature increasing and controlled by the reaction between phosphate and aluminum metal powder.

Citation

Hocine BELHOUCHET , ,(2019), Elaboration and characterization of porous hydroxyapatite materials via the reaction-sintering of phosphate and aluminium powder,9th International advances in applied physics & materials science,Turkey

The structural transformations of kaolin–aluminium slag mixtures during heating werestudied using differential thermal analysis (DTA), thermal gravimetric analysis (TGA),Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction analysis (XRD) and scanningelectron microscopy (SEM). The amount of formed mullite increases with the firing temper-ature. At 1500◦C, the mullitization of the mixture is almost complete. The morphology ofthe formed mullite is bimodal (primary and secondary phases). The primary mullite, formedfrom processing of kaolin by the gradual collapse of metakaolin from 990◦C, has a shape ofelongated crystals. The other hand, the secondary mullite formed by solution-precipitationfrom the glass phase in the presence of alumina particles has a shape of acicular grains.

Citation

Hocine BELHOUCHET , , (2018), Mullite fabrication from natural kaolin and aluminium slag, Boletin de la Sociedad Espanola de Ceramica y Vidrio, Vol:57, Issue:, pages:169-177, Elsevier

The kinetics of discontinuous precipitation of Ag2Al intermetallic in alloy Al – 10 % Ag is studied after 10-h holding in vacuum at 530 °C and subsequent water quenching. The DSC and dilatometric curves are plotted for heating rates ranging from 5 to 20 °Cmin. The activation energy of formation of the Ag2Al -phase is computed from the DSC data with the help of the Boswell equation by the Kissinger method.

Citation

Hocine BELHOUCHET , M. Fatmi, F. Sahnoune, M. Heraiz, N. Saheb, , (2018), Heat treatment and kinetics of precipitation of β-Mg17Al12phase in AZ91 alloy, Results in Physics, Vol:10, Issue:, pages:693-698, /

The aim of the present work is to explore the utilization of Algerian kaolin (DD2) and calcium carbonate (CaCO3) to synthesis of anorthite. Also, the effect of B2O3 addition on the properties of prepared anorthite was investigated. Compacted samples were sintered at temperatures between 1100 and 1300 C for 2 h. All samples were characterized by X-ray diffraction, differential thermal analysis/thermogravimetric analysis, apparent density and open porosity measurements. The experimental results show the formation of anorthite in all samples. The increase in B2O3 ratio promoted the formation and the densification of anorthite at lower temperature.

Citation

Hocine BELHOUCHET , A. Mokhtari, F. Sahnoune, , (2018), The effects of B2O3 addition on the properties of anorthite prepared from Algerian kaolin, Acta Physica Polonica A, Vol:134, Issue:, pages:460-462, /

The kinetics of discontinuous precipitation of Ag2Al intermetallic in alloy Al – 10% Ag is studied after 10-h holding in vacuum at 530°C and subsequent water quenching. The DSC and dilatometric curves are plotted for heating rates ranging from 5 to 20 Kmin. The activation energy of formation of the Ag2Al -phase is computed from the DSC data with the help of the Boswell equation and by the Kissinger method.

Citation

Hocine BELHOUCHET , M.Fatmi, F. Sahnoune, M. Heraiz, N. Saheb, , (2018), Dilatometric and DSC Study of the Kinetics of Discontinuous Precipitation of Ag2Al Intermetallic in Al – 10% Ag Alloy, Metal Science and Heat Treatment, Vol:60, Issue:, pages:185–189, /

In this work we have studied the thermal shock behavior of mullite prepared locally under different conditions. The initial powders used are 60% of trihydrate alumina (Gibbsite) and 40% of natural Kaolin. The specimen shaping was obtained by uniaxial pressing the mixture powders under three pressures (100, 80 and 70) MPa. After debinding at 600°C, precooked samples were sintered at 1600°C for 1h. Differential thermal analysis coupled with thermogravimetric analysis, conducted on the mixture kaolin-gibbsite, revealed different microstructural transformations and reactions occurring during heating. The spectra X-ray diffraction showed the presence of mullite. Observations of the microstructures showed a bi-modal morphology of the mullite grains. A water-quenching technique was used for the thermal shock tests. The Mullite specimens were heated at different temperatures (100°C to 500°C), and held at each temperature for 10 min. Then, the heated specimens were dropped by free fall into a water bath, which was maintained at 25°C with a thermostat. The residual strengths of the quenched specimens were determined in a three-point bending test. The results showed that the quenching critical temperature difference ΔTc depends on density and porosity of the samples.

Citation

Hocine BELHOUCHET , Zahra Malou, Mohamed Hamidouche, , (2018), Thermal Shock Resistance of Mullite obtained from Kaolin and Tri-hydrated Alumina, High Temperatures-High Pressures, Vol:47, Issue:2, pages:179-190, /

The aim of this work is the substitution of the bovine bone by the natural phosphate from Djebelel-Onk (Tébessa, East of Algeria). We prepared two composites (bone/Al2O3 and natural phosphate/Al2O3) by reaction sintering. Different experimental techniques, including density, porosity, X-rays diffraction, and SEM techniques, were used to analyze the formation and transformation of phases at different temperatures. From the X-ray diffraction patterns, we put in evidence the formation of several phases. Through these results, we lighted the possibility of preparing bioceramics from natural phosphate (bone and natural phosphate). The presence of the different materials was confirmed by the micrographic observations. DOI: 10.12693/APhysPolA.131.117 PACS/topics: 81.05.Je, 81.05.Mh, 87.85.jf

Citation

Hocine BELHOUCHET , Foudil SAHNOUNE , MENAD Heraiz , , (2017), Elaboration and Characterization of Bioceramics from Natural Phosphate, ACTA PHYSICA POLONICA A, Vol:131, Issue:1, pages:117-119, POLISH ACAD SCIENCES INST PHYSICS

investigated by using differential thermal analysis. The differential thermal analysis and the thermogravimetric experiments were carried out on samples between room temperature and 1400 °C, at heating rates from 10 to 40 °Cmin-1. X-ray diffraction was used to identify the phases present in the samples. The activation energies measured by differential thermal analysis from isothermal and non-isothermal treatments using Johnson-Mehl- Avrami methods with Ligero approximation and using Kissinger-Akahira-Sunose methods were around 145 and 159 kJ/mol, respectively. The Avrami parameter n which indicates the growth morphology parameters were found to be almost equal to 1.60, using non-isothermal treatments, and equal to 1.47 using isothermal treatments. The numerical factor which depends on the dimensionality of crystal growth was 1.60 obtained using Matusita et al. equation. The frequency factor calculated using the isothermal treatment is equal to 1.173 * 107 s-1. Analysis of the results have shown that bulk nucleation was dominant during kaolinite transformation, followed by three-dimensional growth of meta-kaolinite with polyhedron-like morphology, controlled by diffusion from a constant number of nuclei. DOI: 10.12693/APhysPolA.131.382 PACS/topics: 82.30.Lp, 81.05.Je, 81.05.Mh, 81.70.Pg

Citation

Foudil SAHNOUNE , MENAD Heraiz , Hocine BELHOUCHET , Nouari Saheb, Djida Redaoui,, , (2017), Thermal Decomposition Kinetics of Algerian Tamazarte Kaolin by Differential Thermal Analysis (DTA), ACTA PHYSICA POLONICA A, Vol:131, Issue:3, pages:382-385, POLISH ACAD SCIENCES INST PHYSICS

the effect of soda lime silica waste glass, from the glass ca broken in partial replacement of k-feldespar for porcelain insulators are disscussed. in this study, different mixes of four different materials namely; Kaolin from Tamazert, quartz from Tamerasset feldespar from Spain and recycle soda-lime-silica were prepared by sintering the samples between 1000 and 1300°C for 2 h. Mesearments have been performed by X-ray diffraction, scanning electron microscopy, DTA/TG, water absorption, and mechanical tests. Experimental results showed a significant improvement in physical and michanical properties. the microstructure observasion indicated that replacement of K- feldespar by the soda-lime-silica waste can facilate the sintering of the porcelain insulators. Finally, the addition of the soda-lime-silica improves the dielectric properties.

Citation

Khaled BELHOUCHET , Hocine BELHOUCHET , ,(2015), Effect of soda- lime- silica waste glass on the properties and microstructures development in porcelain insulator,Conference materiaux 2015,Mahdia, Tunisia

In this work, different composites (zircon–mullite–zirconia, mullite–zircon–zirconia, mullite–zirconia, mullite– zirconia–alumina and alumina–mullite–zirconia) were developed by reaction sintering of boehmite (AlOOH) and zircon (ZrSiO4). Several mixtures were used by varying the boehmite content from 10 to 90 wt. %. All powders were mixed and grounded by ball milling and then pressed in cylindrical form. Finally, the green specimens were sintered under normal conditions for 2 hours at temperatures between 1400 and 1600°C, with a heating rate of 5°C/min. The dilatometric curves reveal several microstructural transformations in these mixtures. The X-rays diffraction spectra revealed factors such as percentage of boehmite and zircon and the sintering temperature lead to the formation of several composites. The presence of the various phases was confirmed by micrographic observations.

Citation

Hocine BELHOUCHET , Hocine MAKRI , , (2014), Elaboration and characterization of multiphase composites obtained by reaction sintering of boehmite and zircon, Journal of the Australian Ceramic Society, Vol:50, Issue:2, pages:135 – 146, Australian Ceramic Society