TY - JOUR AU - FADOUL MOHAMMED IBRAHIM, JAMAL ELDIN AU - Kurovics, Emese AU - TIHTIH, Mohammed AU - Basyooni, Mohamed A. AU - Kocserha, István TI - Reaction synthesis of porous nano-structured mullite ceramic composites from alumina and zeolite-poor rock with enhanced strength and low thermal conductivity JF - RESULTS IN ENGINEERING J2 - RESULT ENGIN VL - 20 PY - 2023 PG - 10 SN - 2590-1230 DO - 10.1016/j.rineng.2023.101423 UR - https://m2.mtmt.hu/api/publication/34474887 ID - 34474887 AB - Porous mullite-based ceramics have been developed using a mixture of zeolite-poor rock and alumina through mechanical activation and reactive sintering. The experimental findings demonstrate that the in-situ mullite growth may develop in a variety of shapes, including whiskers, nanofiber, nanonetwork and diamond-like particles. The XRD examination indicates that the samples sintered at 1500 °C are mostly made of the mullite phase. The SEM photographs show that as the sintering temperature increases, the mullitization process takes place first in zeolite-poor rock particles, and subsequently, alumina combines with the silica-containing phase via a liquid-phase sintering mechanism to produce an interlocking network of extended secondary mullite. The effects of mullite formation and the sintering temperature on various properties of the sintered samples, such as their density, apparent porosity, thermal conductivity, strength, wear resistance, composition, morphologies, and microstructural characteristics of the sintered samples were studied. Increasing the sintering temperature from 1100 to 1500 °C improved the different properties. The density increased from 1.9 to 2.1 g/cm3, thermal conductivity rose from 0.9 to 1.6 W/m.K, compressive strength escalated from 18.9 to 92.1 MPa, and worn material volume decreased from 2444 to 36.9 mm3 after a 5-min abrasion test. LA - English DB - MTMT ER - TY - JOUR AU - Simon, Andrea AU - Kurovics, Emese AU - Mucsi, Gábor AU - Kocserha, István TI - Az égetési hőmérséklet hatása az Al2O3-üveg kompozit tulajdonságaira JF - ÉPÍTŐANYAG: JOURNAL OF SILICATE BASED AND COMPOSITE MATERIALS J2 - ÉPÍTŐANYAG-JSBCM VL - 75 PY - 2023 IS - 4 SP - 136 EP - 141 PG - 6 SN - 0013-970X DO - 10.14382/epitoanyag-jsbcm.2023.19 UR - https://m2.mtmt.hu/api/publication/34445383 ID - 34445383 LA - Hungarian DB - MTMT ER - TY - JOUR AU - Mohammed, Al-Saudi Sarah kareem AU - Géber, Róbert AU - Simon, Andrea AU - Kurovics, Emese AU - Hamza, Alexandra TI - Comparative study of metakaolin-based geopolymer characteristics utilizing different dosages of water glass in the activator solution JF - RESULTS IN ENGINEERING J2 - RESULT ENGIN VL - 20 PY - 2023 PG - 10 SN - 2590-1230 DO - 10.1016/j.rineng.2023.101469 UR - https://m2.mtmt.hu/api/publication/34186523 ID - 34186523 LA - English DB - MTMT ER - TY - JOUR AU - FADOUL MOHAMMED IBRAHIM, JAMAL ELDIN AU - TIHTIH, Mohammed AU - Kurovics, Emese AU - Şahin, Ethem İlhan AU - Gömze, Antal László AU - Kocserha, István TI - Glass-Ceramic Foams Produced from Zeolite-Poor Rock (Tokaj) JF - POLLACK PERIODICA: AN INTERNATIONAL JOURNAL FOR ENGINEERING AND INFORMATION SCIENCES J2 - POLLACK PERIODICA VL - 18 PY - 2023 IS - 1 SP - 119 EP - 125 PG - 7 SN - 1788-1994 DO - 10.1556/606.2022.00641 UR - https://m2.mtmt.hu/api/publication/33210574 ID - 33210574 AB - This study evaluated the possibility of producing innovative glass-ceramic foams from zeolite-poor rock (Tokaj, Hungary) using alkali-activation and reactive sintering techniques. The composition and morphology of the samples were studied using X-ray diffraction, X-ray fluorescence, scanning electron microscope, and computed tomography techniques. The influence of various sintering temperatures on glass-ceramic foams was examined. It has been observed that zeolite-poor rock has a self-foaming capability. The heat treatment temperature affects the pore size and distribution as well as the technical characteristics of the obtained samples. The resulting glass-ceramic foams possess moderate thermal conductivity ranging from 0.11 to 0.17 W mK-1 and good compressive strength (1.5–4.4 MPa). The produced samples might be utilized for thermal insulation, which would have both economic and environmental advantages. LA - English DB - MTMT ER - TY - JOUR AU - TIHTIH, Mohammed AU - FADOUL MOHAMMED IBRAHIM, JAMAL ELDIN AU - Basyooni, Mohamed A. AU - Kurovics, Emese AU - Belaid, Walid AU - Hussainova, Irina AU - Kocserha, István TI - Role of A-site (Sr), B-site (Y), and A, B sites (Sr, Y) substitution in lead-free BaTiO3 ceramic compounds: Structural, optical, microstructure, mechanical, and thermal conductivity properties JF - CERAMICS INTERNATIONAL J2 - CERAM INT VL - 49 PY - 2023 IS - 2 SP - 1947 EP - 1959 PG - 13 SN - 0272-8842 DO - 10.1016/j.ceramint.2022.09.160 UR - https://m2.mtmt.hu/api/publication/33191337 ID - 33191337 LA - English DB - MTMT ER - TY - JOUR AU - Kurovics, Emese AU - FADOUL MOHAMMED IBRAHIM, JAMAL ELDIN AU - TIHTIH, Mohammed AU - Sebe, Emese TI - Phase composition and microstructure of ceramics made from kaolin mineral, alumina, and corn starch JF - ÉPÍTŐANYAG: JOURNAL OF SILICATE BASED AND COMPOSITE MATERIALS J2 - ÉPÍTŐANYAG-JSBCM VL - 74 PY - 2022 IS - 6 SP - 237 EP - 240 PG - 4 SN - 0013-970X DO - 10.14382/epitoanyag-jsbcm.2022.34 UR - https://m2.mtmt.hu/api/publication/33588272 ID - 33588272 AB - In this work, Sedlecky ml kaolinite, Nabalox No. 315 alumina and corn starch were used. The powder mixtures were milled and uniaxially pressed into pellets. Some properties of the raw materials and mixtures were investigated like TG, DTA, and the gas composition formed during the sintering process. The pellet samples were pre-sintered in the electric kiln under an oxygenfree reduction atmosphere at 1250 °C and then sintered in nitrogen gas at 1450 °C. The composition and microstructure of the produced specimens were tested. The pyrolysis results show that in reducing pre-sintering 25 wt% of the mass of the corn additive remove from the ceramic body as gas. The remained part of the corn can incorporate into the material structure, and it may affect the further heat treatment processes. The mullite content of the ceramic samples increased from 43 wt% to 70 wt% because of high-temperature sintering in nitrogen gas. The mullite crystal structure has also changed. The increase in the amount of mullite phase is a consequence of the sintering process since the free SiO2 and Al2O3 formed mullite crystals. Keywords: alumina, free SiO2, mullite, pyrolysis, sintering process LA - English DB - MTMT ER - TY - JOUR AU - TIHTIH, Mohammed AU - FADOUL MOHAMMED IBRAHIM, JAMAL ELDIN AU - Kurovics, Emese AU - Mohammed, Al-Saudi Sarah kareem AU - Kocserha, István TI - Characterization of Bi and Fe doping BaTiO3 nanoceramics prepared by Sol-gel method JF - Doktorandusz Almanach J2 - Doktorandusz Almanach VL - 1 PY - 2022 SP - 40 EP - 50 PG - 11 SN - 2939-7294 UR - https://m2.mtmt.hu/api/publication/33351300 ID - 33351300 AB - Fe-doped barium titanate (BFexT) and Bismuth (Bi) doped barium titanate (BaTiO3) nanoceramics were successfully prepared by a simple sol-gel process, these materials are very interesting and could be a candidate for many optoelectronic applications. X-ray diffraction (XRD) patterns of the obtained samples, heat-treated at a quite low temperature (800 °C/3h) revealed that BFexT and BBixT nanoceramics crystallized into a tetragonal phase perovskite structure. The occupation of the Ba and Ti sites by Fe and Bi in the BaTiO3 lattice and the evolution of the different parameters (crystallite size, lattice parameters and strain) as functions of the Fe doping have been discussed in details using several characterization techniques including XRD and Fourier Transformation Infrared (FT-IR). The band gap of the Bi-doped BaTiO3 nanopowders is lower compared to that of pure BaTiO3, as determined from the analysis of UV absorbance spectra. LA - English DB - MTMT ER - TY - JOUR AU - Mohammed, Al-Saudi Sarah kareem AU - Kurovics, Emese AU - FADOUL MOHAMMED IBRAHIM, JAMAL ELDIN AU - TIHTIH, Mohammed AU - Simon, Andrea AU - Géber, Róbert TI - Preparation of an Aluminum Titania /Mullite Composite from the Raw Materials Alumina, Titania and Silica Fume JF - Revue des Composites et des Materiaux Avances J2 - Revue des Composites et des Materiaux Avances VL - 32 PY - 2022 IS - 5 SP - 223 EP - 228 PG - 6 SN - 1169-7954 DO - 10.18280/rcma.320502 UR - https://m2.mtmt.hu/api/publication/33292604 ID - 33292604 AB - The present work deals with the preparation of ceramic composites and the study of phase transformation. Three mixtures were prepared, the main mixture containing (80 wt%) alumina and (20 wt%) titania and the other two mixtures to which two amounts of silica fume were added at (5 and 10 wt%). The phase transformation was studied at two temperatures: 1200℃ and 1400℃. The X-ray diffraction results at 1200℃ show that the amorphous silica (silica fume) transformed into the crystalline phase cristobalite. At 1400℃, aluminum titanate formed by the reaction of alumina with titania, and mullite formed by the reaction of alumina with silica. The result of scanning electron microscopy shows that the addition of (5 wt%) silica leads to a microstructure with smaller grain size up to (500 nm), a lower porosity (20 vol%), a lower water absorption (7 wt%) and a thermal conductivity (1.514W/m.k). LA - English DB - MTMT ER - TY - JOUR AU - FADOUL MOHAMMED IBRAHIM, JAMAL ELDIN AU - TIHTIH, Mohammed AU - Kurovics, Emese AU - Gömze, Antal László AU - Kocserha, István TI - Innovative Glass-Ceramic Foams Prepared by Alkali Activation and Reactive Sintering of Zeolite-Poor Rock and Sawdust JF - SOCIAL SCIENCE RESEARCH NETWORK: SSRN J2 - SOC SCI RES NETW (SSRN) VL - 1 PY - 2022 PG - 38 SN - 1556-5068 DO - 10.2139/ssrn.4065693 UR - https://m2.mtmt.hu/api/publication/33210518 ID - 33210518 LA - English DB - MTMT ER - TY - CONF AU - Mohammed, Al-Saudi Sarah kareem AU - Kurovics, Emese AU - FADOUL MOHAMMED IBRAHIM, JAMAL ELDIN AU - TIHTIH, Mohammed AU - Simon, Andrea AU - Géber, Róbert AU - Gömze, Antal László ED - Molnár, Dániel ED - Molnár , Dóra TI - STUDY OF THE PROPERTIES OF ALUMINUM TITANATE WITH THE ADDITION OF SILICA FUME T2 - XXV. Tavaszi Szél Konferencia 2022. Absztraktkötet PB - Doktoranduszok Országos Szövetsége (DOSZ) C1 - Budapest SN - 9786158205481 PY - 2022 SP - 782 UR - https://m2.mtmt.hu/api/publication/33204709 ID - 33204709 AB - Materials science research in general and ceramics in particular are evolving at a rapid pace. To achieve the best properties, ceramic technologies today aim to produce superior ceramic products from readily available raw materials. Aluminum titanate ceramic is a composite material mainly used as a refractory material in casting aluminum alloys compared to molten aluminum alloys. It is versatile due to its high melting temperature, excellent chemical resistance, low thermal expansion and excellent thermal shock resistance. In this work, the formation of aluminum titanate was studied by sintering at 1400°C samples prepared from mixtures of 80 wt% alumina and 20 wt% titania with the addition of 5 and 10 wt% silica fume. X-ray diffraction and scanning electron microscopy results show that the addition of silica stabilizes the structure of aluminum titanate Al2TiO5, and the mullite phase appears as a product of alumina Al2O3 and silica SiO2. Mullite has a wide range of applications as it has good mechanical and thermal properties. Silica Fume is a powdery by-product resulting from gasses evaporated during the production of silicon or ferrosilicon alloys. It is a very fine, noncrystalline, spherical powder with a material size up to 0.1µm. The sample with 5 wt% silica fume has the best properties because a small percentage of silica leads to stabilization of the aluminum titanate while improving the microstructure, which consists of small particle sizes, while too high a concentration of silica fume leads to grain growth, which negatively affects mechanical strength. The sample with 5 wt% has low porosity, low water absorption and low thermal conductivity value. This makes it attractive for applications such as thermal barriers, combustion engines and catalyst reference materials LA - English DB - MTMT ER -