@{MTMT:34445038, title = {INVESTIGATION OF THE PROPERTIES OF FOAM GLASS PRODUCED FROM WINDOW GLASS WASTE AND VARIOUS FOAMING AGENTS}, url = {https://m2.mtmt.hu/api/publication/34445038}, author = {Mohammed, Al-Saudi Sarah kareem and Simon, Andrea and Géber, Róbert}, booktitle = {XXVI. Tavaszi Szél Konferencia 2023 : Absztrakt kötet}, unique-id = {34445038}, abstract = {Foam glass, an advanced type of environmentally friendly material made from waste, has a porous structure. The type of pores determines the properties and applications of foam glass. Closed-cell foam glass, in which the open porosity is less than 10 vol.%, is a building material that outperforms typical thermal insulation materials in terms of low thermal conductivity, compressive strength of higher than 0.5 MPa, water resistance and long service life. When used in subway stations and gardens, open-pore foam glass with an open porosity of more than 50 vol.% provides high sound insulation. Soda-lime glass waste is generated in large quantities from bottle and window waste glass. The main components are sodium silicate and calcium silicate. The selection of the appropriate foaming agent is very important for pore formation, because the whole process is based on the reactions of the foaming agent at high temperatures and also the viscosity of the mixture. In this work, foam glass samples were prepared by used soda-lime-silicate (SLS) waste glass (window glass) and different foaming agents like silicon carbide (SiC), limestone (CaCO3) and titanium dioxide (TiO2) at two foaming temperatures (800°C and 850°C). Limestone decomposes at temperatures 750°C to 900°C, producing large amounts of CO2 gas, and is therefore likely to form an open-pore structure. Limestone combined with SiC and TiO2 were added to form composite foams. The physical properties (density, water absorption and apparent porosity), microstructure, thermal conductivity and phase composition of the foam glass were measured. At a foaming temperature of 800°C, the SLS glass foam samples exhibited low water absorption (0.73-1.57wt.%) ,bulk density (0.27- 0.04 g/cm3 ), and thermal conductivity (0.063-0.140 W/m·k). When the foaming temperature was increased to 850°C, the water absorption increased sharply due to the increased number of open cells formed. Depending on the foam microstructure, the water absorption was in the range of (53-98 wt.%) and decreased the bulk density (0.04-0.083 g/cm3 ) and thermal conductivity (0.040-0.083 W/m·k)}, year = {2023}, pages = {268}, orcid-numbers = {Géber, Róbert/0000-0002-0973-863X} } @CONFERENCE{MTMT:34394902, title = {Tensile Strength Investigation of Polyamide 6.12 Reinforced by Glass Fiber 30%}, url = {https://m2.mtmt.hu/api/publication/34394902}, author = {S.H., Yoshanlouei and Géber, Róbert and Polyákné Kovács, Annamária}, booktitle = {Book of Abstracts from 9th International Scientific Conference on Advances in Mechanical Engineering}, unique-id = {34394902}, year = {2023}, pages = {120}, orcid-numbers = {Géber, Róbert/0000-0002-0973-863X} } @article{MTMT:34186523, title = {Comparative study of metakaolin-based geopolymer characteristics utilizing different dosages of water glass in the activator solution}, url = {https://m2.mtmt.hu/api/publication/34186523}, author = {Mohammed, Al-Saudi Sarah kareem and Géber, Róbert and Simon, Andrea and Kurovics, Emese and Hamza, Alexandra}, doi = {10.1016/j.rineng.2023.101469}, journal-iso = {RESULT ENGIN}, journal = {RESULTS IN ENGINEERING}, volume = {20}, unique-id = {34186523}, year = {2023}, eissn = {2590-1230}, orcid-numbers = {Géber, Róbert/0000-0002-0973-863X; Kurovics, Emese/0000-0001-5669-3318} } @article{MTMT:33762624, title = {Structure and properties of ZrO2-Al2O3-MgO porous ceramic for biomedical applications}, url = {https://m2.mtmt.hu/api/publication/33762624}, author = {ALSHALAL, RUSUL AHMED SHAKIR and Géber, Róbert}, doi = {10.1016/j.rineng.2023.101104}, journal-iso = {RESULT ENGIN}, journal = {RESULTS IN ENGINEERING}, volume = {18}, unique-id = {33762624}, abstract = {Starch consolidation casting (SCC), which involves pouring starch-containing slurries into an impermeable mould, is a flexible, easy, not harmful, not expensive, and firmly established method for manufacturing ceramic green structures. The procedure depends on the fact that the starch granules, when heated to about 80 °C, start to swell and absorb the water from the ceramic slurries. Following sintering, the starch granules have been completely destroyed by burning, resulting in the formation of porous-structured ceramics. In the current study, porous zirconia-alumina–magnesia (77.5 wt% ZrO2, 2.5 wt% MgO, and 20 wt% Al2O3) ceramic composites have been produced using starch consolidation casting method at different suspension concentration (60, 65, and 70 wt%). Potato or tapioca starches with varying quantities (10, 20, and 30 wt% related to the solid ceramics) were used as a pore and body forming agents. The sintered microstructures were investigated using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Furthermore, the research activity investigates how the apparent density and apparent porosity of the porous ceramic structure that has been produced are affected by the addition of different proportions of starches in different suspension concentrations. The XRD result after sintering reveals monoclinic zirconia, indicating that the tetragonal phase of zirconia is not stabilized by MgO and returns to monoclinic upon cooling. Magnesia does not act as a stabilizer for zirconia, but it is combined with alumina to produce a spinel structure. Maximum apparent porosity value of around 73% were demonstrated for porous-structured ceramics made with (30 wt%) potato starch and (60 wt%) suspension concentration. The SEM analysis of porous-structured ceramics revealed the presence of pore fills in the shape of miniature sintered ceramic shells within the pores. These shells form throughout the drying and burn-out processes, when the starch granules undergo a process that causes them to shrink. For nominal starch quantities of approximately 10 wt%, starch swelling is noticeable, and the pores left behind by sintering are bigger than the starch granules. Swelling is limited for greater amounts of starch by the amount of available space and/or water, and the matrix shrinkage that occurs during sintering more than compensates for the swelling impact, resulting in ceramic pores much smaller than the initial starch granule size. SEM and high-pressure mercury porosimetry results indicated that the prepared porous-structured ceramics have a bimodal pore structure. The maximum compressive strength at around 15.87 MPa for a sample containing 10 wt% tapioca starch and 70 wt% suspension concentration. Compressive strength drastically reduced when starch content increased from 10 to 30 wt% and suspension concentration reduced from 70 to 60 wt%.}, keywords = {Porosity; Biomedical applications; Porous structure; Starch consolidation casting; Alumina-zirconia-magnesia composites; Pore- and body-forming agents; Swelling factor}, year = {2023}, eissn = {2590-1230}, orcid-numbers = {Géber, Róbert/0000-0002-0973-863X} } @article{MTMT:33187834, title = {Enhancing the properties of lightweight aggregates using volcanic rock additive materials}, url = {https://m2.mtmt.hu/api/publication/33187834}, author = {Abdelfattah, Mohamed and Géber, Róbert and Kocserha, István}, doi = {10.1016/j.jobe.2022.105426}, journal-iso = {J BUILDING ENG}, journal = {JOURNAL OF BUILDING ENGINEERING}, volume = {63}, unique-id = {33187834}, year = {2023}, eissn = {2352-7102}, orcid-numbers = {Abdelfattah, Mohamed/0000-0001-7339-255X; Géber, Róbert/0000-0002-0973-863X; Kocserha, István/0000-0003-0904-933X} } @article{MTMT:33540979, title = {Geopolimer nyomószilárdságának növelése különböző adalékanyagokkal}, url = {https://m2.mtmt.hu/api/publication/33540979}, author = {Udvardi, Bella and Kocserha, István and Géber, Róbert}, journal-iso = {Doktorandusz Almanach}, journal = {Doktorandusz Almanach}, volume = {1}, unique-id = {33540979}, issn = {2939-7294}, year = {2022}, pages = {14-20}, orcid-numbers = {Géber, Róbert/0000-0002-0973-863X} } @article{MTMT:33532636, title = {Starch Consolidation Casting Method for Preparation Of ZrO2–Al2O3–MgO Porous Structure}, url = {https://m2.mtmt.hu/api/publication/33532636}, author = {Shakir, Rusul Ahmed and Géber, Róbert}, doi = {10.35925/j.multi.2022.4.25}, journal-iso = {MULTIDISZCIPLINÁRIS TUDOMÁNYOK}, journal = {MULTIDISZCIPLINÁRIS TUDOMÁNYOK: A MISKOLCI EGYETEM KÖZLEMÉNYE}, volume = {12}, unique-id = {33532636}, issn = {2062-9737}, abstract = {The starch consolidation casting (SCC) method was used for the preparation of porous structure ceramic based on partially stabilized ZrO2 with other oxides such as MgO and Al2O3 with the addition of tapioca and potato starch as a binder and pore-forming agents. For casting purpose, three impermeable plastic moulds were designed and manufactured with different sizes and shapes depending on the shape and size of the required samples. The method is based on the fact that after being heated to about 80°C, starch may swell and absorb water from aqueous ceramic solutions. The process's simplicity, the ability to create complicated shapes using different moulds, and the inexpensive cost of the necessary processing tools and materials are its main benefits.}, year = {2022}, eissn = {2786-1465}, pages = {232-241}, orcid-numbers = {Shakir, Rusul Ahmed/0000-0001-6010-8193; Géber, Róbert/0000-0002-0973-863X} } @article{MTMT:33292604, title = {Preparation of an Aluminum Titania /Mullite Composite from the Raw Materials Alumina, Titania and Silica Fume}, url = {https://m2.mtmt.hu/api/publication/33292604}, author = {Mohammed, Al-Saudi Sarah kareem and Kurovics, Emese and FADOUL MOHAMMED IBRAHIM, JAMAL ELDIN and TIHTIH, Mohammed and Simon, Andrea and Géber, Róbert}, doi = {10.18280/rcma.320502}, journal-iso = {Revue des Composites et des Materiaux Avances}, journal = {Revue des Composites et des Materiaux Avances}, volume = {32}, unique-id = {33292604}, issn = {1169-7954}, abstract = {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).}, keywords = {ALUMINA; Titania; Silica fume}, year = {2022}, pages = {223-228}, orcid-numbers = {Kurovics, Emese/0000-0001-5669-3318; Géber, Róbert/0000-0002-0973-863X} } @article{MTMT:33270877, title = {Preparation and characterization of foam glass from soda lime silicate glass waste by using different dosages of limestone}, url = {https://m2.mtmt.hu/api/publication/33270877}, author = {Mohammed, Al-Saudi Sarah kareem and Simon, Andrea and Géber, Róbert}, doi = {10.35925/j.multi.2022.4.20}, journal-iso = {MULTIDISZCIPLINÁRIS TUDOMÁNYOK}, journal = {MULTIDISZCIPLINÁRIS TUDOMÁNYOK: A MISKOLCI EGYETEM KÖZLEMÉNYE}, volume = {12}, unique-id = {33270877}, issn = {2062-9737}, abstract = {Soda-lime silicate (SLS) waste glass is a kind of solid waste that is produced in large quantities as container glass or flat glass. In this work, waste window glass is used to produce foam glass using limestone as a foaming agent. The pore structure of the foam glass and the optimization of its properties by adjusting the amount of glass and foaming agents were investigated in this work. The formation of foam glass was studied on samples prepared from blends of SLS waste glass with 0.5 wt% SiC and 2, 4, 6 wt% limestone by sintering at 800 °C. The foam glass with 2wt % limestone presented a homogeneous foam structure with low body density (0.26 g/cm3), apparent porosity (9 vol%) and thermal conductivity (0.04 W/m∙K). When the limestone content increases to 6 wt %, the density and thermal conductivity of the sample also increases to 0.92 g/cm3 and 0.13 W/m∙K, respectively.}, year = {2022}, eissn = {2786-1465}, pages = {189-197}, orcid-numbers = {Mohammed, Al-Saudi Sarah kareem/0000-0003-3363-6155; Géber, Róbert/0000-0002-0973-863X} } @CONFERENCE{MTMT:33204709, title = {STUDY OF THE PROPERTIES OF ALUMINUM TITANATE WITH THE ADDITION OF SILICA FUME}, url = {https://m2.mtmt.hu/api/publication/33204709}, author = {Mohammed, Al-Saudi Sarah kareem and Kurovics, Emese and FADOUL MOHAMMED IBRAHIM, JAMAL ELDIN and TIHTIH, Mohammed and Simon, Andrea and Géber, Róbert and Gömze, Antal László}, booktitle = {XXV. Tavaszi Szél Konferencia 2022. Absztraktkötet}, unique-id = {33204709}, abstract = {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}, year = {2022}, pages = {782}, orcid-numbers = {Kurovics, Emese/0000-0001-5669-3318; Géber, Róbert/0000-0002-0973-863X} }