Hetero-modulus Nanoparticles Reinforced Corundum Matrix CMC with Extreme Wear and Thermal Shock Resistances

Abstract: A novel approach to obtain ceramic matrix composites with extreme high mechanical wear and thermal shock resistance abilities is presented. The developed corundum matrix composites were reinforced with nanoparticles, submicron fibres and whiskers of Si 2 ON 2 , SiAlON, AlN and Si 3 N 4 . These kinds of materials have several Young's modulus simultaneously. These new alumina based ceramic matrix composites were obliged to collisions with different metallic bodies having high densities and impact speeds larger than 900 m/s at the moment of the hits. During the experiments in the places of collisions where oxygen was absent new high density "diamond-like" c-Si 3 N 4 cubic crystals have developed with spinel structures, where nitrogen atoms were distributed in the centres of the cubes. These new spinel crystals of c-Si 3 N 4 in the alumina matrix have extreme high dynamic strength, hardness and wear resistance, like diamond. They were fully resistance to oxygen and thermal shock at the tested temperature of 1200 o C

Hetero-modulus Nanoparticles Reinforced Corundum Matrix CMC with Extreme Wear and Thermal Shock Resistances

Abstract: A novel approach to obtain ceramic matrix composites with extreme high mechanical wear and thermal shock resistance abilities is presented. The developed corundum matrix composites were reinforced with nanoparticles, submicron fibres and whiskers of Si 2 ON 2 , SiAlON, AlN and Si 3 N 4 . These kinds of materials have several Young's modulus simultaneously. These new alumina based ceramic matrix composites were obliged to collisions with different metallic bodies having high densities and impact speeds larger than 900 m/s at the moment of the hits. During the experiments in the places of collisions where oxygen was absent new high density "diamond-like" c-Si 3 N 4 cubic crystals have developed with spinel structures, where nitrogen atoms were distributed in the centres of the cubes. These new spinel crystals of c-Si 3 N 4 in the alumina matrix have extreme high dynamic strength, hardness and wear resistance, like diamond. They were fully resistance to oxygen and thermal shock at the tested temperature of 1200 o C

Porózus dekoratív kerámiatermékek előállítási lehetőségeinek vizsgálata téglaagyag és alumínium-oxid porok felhasználásával

By using conventional brick and aluminum oxide raw material, the authors have developed a new ceramic composite that can be used for decorative coating of floor heating systems. The powdery ingredients mixed with fine granular sawdust were mixed, and cylindrical specimens were compacted with uniaxial pressure. The samples were incinerated at a temperature of 1050°C, 1150°C and 1250°C in the electrically heated chamber furnace. The results obtained by the authors shows the effect of the mixture composition and the heat treatment conditions on the shrinkage, porosity and thermal conductivity of the prepared specimens as well as the physical properties of the product as the color.Hagyományos téglaagyag és a műszaki kerámiaipari alapanyagként ismert alumíniumoxid felhasználásával a szerzők olyan új kerámia kompozitot fejlesztettek ki, amely felhasználható padlófűtési rendszerek dekoratív burkolására. A porszerű alapanyagokból finom szemcsés fűrészporral több összetétel alkalmazásával keverékeket készítettek, majd egytengelyű porsajtolással henger formájú próbatesteket sajtoltak. A minták égetése 1050°C, 1150°C illetve 1250°C-os maximális hőmérséklettel történt elektromos fűtésű kamrás kemencében. A szerzők által kapott vizsgálati eredmények jól mutatják a keverék összetétel és a hőkezelési körülmények hatását az elkészült próbatestek zsugorodására, porozitására, hővezető-képességére, valamint a termék olyan fizikai tulajdonságaira is, mint a szín.&nbsp

Porózus dekoratív kerámiatermékek előállítási lehetőségeinek vizsgálata téglaagyag és alumínium-oxid porok felhasználásával

Absztrakt: Hagyományos téglaagyag és a műszaki kerámiaipari alapanyagként ismert alumíniumoxid felhasználásával a szerzők olyan új kerámia kompozitot fejlesztettek ki, amely felhasználható padlófűtési rendszerek dekoratív burkolására. A porszerű alapanyagokból finom szemcsés fűrészporral több összetétel alkalmazásával keverékeket készítettek, majd egytengelyű porsajtolással henger formájú próbatesteket sajtoltak. A minták égetése 1050°C, 1150°C illetve 1250°C-os maximális hőmérséklettel történt elektromos fűtésű kamrás kemencében. A szerzők által kapott vizsgálati eredmények jól mutatják a keverék összetétel és a hőkezelési körülmények hatását az elkészült próbatestek zsugorodására, porozitására, hővezető-képességére, valamint a termék olyan fizikai tulajdonságaira is, mint a szín. Abstract: By using conventional brick and aluminum oxide raw material, the authors have developed a new ceramic composite that can be used for decorative coating of floor heating systems. The powdery ingredients mixed with fine granular sawdust were mixed, and cylindrical specimens were compacted with uniaxial pressure. The samples were incinerated at a temperature of 1050°C, 1150°C and 1250°C in the electrically heated chamber furnace. The results obtained by the authors shows the effect of the mixture composition and the heat treatment conditions on the shrinkage, porosity and thermal conductivity of the prepared specimens as well as the physical properties of the product as the color

The effect of temperature and composition to the rheological properties of asphalt pavements;

Abstract. Ceramics, concretes and asphalt-mixtures are the most popular building materials in Hungary, because of the highway programme of the government. In spite of their large popularity, some of the mechanical properties of ceramics, concretes and asphalts are not investigated enough till today. Particularly, there is no mechanical model usable to understand and explain the rheological behaviours of these materials with different compositions of mineral raw materials. It is well known, that the viscosity of viscous materials, viscoelastic materials, and viscoplastic materials dynamically decreases, as the temperature increases. The decrease of viscosity by leaps and bounds could be extremely dangerous in case of asphalt pavements in the range of 55 -75 °C, due to the crossing of cars on the low viscosity pavements which suffer inelastic deformation, as a result. Using a Rheo-tribometer instrument developed by L. A. Gömze and others, the authors have investigated and tested asphalt mixtures with different composition of mineral raw materials, and would like to reveal and review the dependence of the rheological properties of these pavements against the temperature, and the intensity of the dependence