The Experts below are selected from a list of 270 Experts worldwide ranked by ideXlab platform
Marco Antonio Durlo Tie - One of the best experts on this subject based on the ideXlab platform.
-
development of Refractory Ceramics from residual silica derived from rice husk ash and steel fibres
Ceramics International, 2017Co-Authors: N P Stochero, Ederli Marango, A S Nunes, Marco Antonio Durlo TieAbstract:Abstract Despite their high hardness and thermal stability, Refractory Ceramics have a tendency to undergo failure due to fatigue and thermal shock. In this study, the effects of rice husk silica and steel fibres on the mechanical and thermal properties of Refractory ceramic materials were investigated. Samples were fabricated by replacing kaolin clay with 20% rice husk silica and 3%, 6% or 9% steel fibres in volume percentages. These specimens were analysed for their mineralogical composition, density, apparent porosity, tensile strength in a three-point bending test, thermal shock and microstructural analysis by scanning electron microscopy. For materials with silica and clay, a reduction in porosity and increase in mechanical resistance was observed. Ceramics with 9% steel fibre had the greatest ductility, while materials with 3% and 6% steel fibre presented the highest resistance against thermal shock.
-
development of Refractory Ceramics from residual silica derived from rice husk ash
Ceramics International, 2017Co-Authors: F Z Sobrosa, N P Stochero, Ederli Marango, Marco Antonio Durlo TieAbstract:Abstract Rice husk has been used as a thermal energy source for electricity generation, resulting in the formation of silica from rice husk as a by-product. This research aims to develop Refractory ceramic materials by replacing kaolin clay with rice husk silica at 5%, 10% and 20% volume percentages. The samples were investigated in terms of their density, apparent porosity, tensile strength in three-point bending test, compressive strength, thermal shock and mineralogical composition. The use of 20% silica resulted in an increase in the formation of cristobalite, higher packing of granular mixtures, and consequently, an improvement in the tensile strength and compression strength of the samples. However, the material that was most successful in increasing the mechanical strength without decreasing the thermal shock strength was the sample processed with 10% clay replacement by silica from rice husk.
N P Stochero - One of the best experts on this subject based on the ideXlab platform.
-
development of Refractory Ceramics from residual silica derived from rice husk ash and steel fibres
Ceramics International, 2017Co-Authors: N P Stochero, Ederli Marango, A S Nunes, Marco Antonio Durlo TieAbstract:Abstract Despite their high hardness and thermal stability, Refractory Ceramics have a tendency to undergo failure due to fatigue and thermal shock. In this study, the effects of rice husk silica and steel fibres on the mechanical and thermal properties of Refractory ceramic materials were investigated. Samples were fabricated by replacing kaolin clay with 20% rice husk silica and 3%, 6% or 9% steel fibres in volume percentages. These specimens were analysed for their mineralogical composition, density, apparent porosity, tensile strength in a three-point bending test, thermal shock and microstructural analysis by scanning electron microscopy. For materials with silica and clay, a reduction in porosity and increase in mechanical resistance was observed. Ceramics with 9% steel fibre had the greatest ductility, while materials with 3% and 6% steel fibre presented the highest resistance against thermal shock.
-
development of Refractory Ceramics from residual silica derived from rice husk ash
Ceramics International, 2017Co-Authors: F Z Sobrosa, N P Stochero, Ederli Marango, Marco Antonio Durlo TieAbstract:Abstract Rice husk has been used as a thermal energy source for electricity generation, resulting in the formation of silica from rice husk as a by-product. This research aims to develop Refractory ceramic materials by replacing kaolin clay with rice husk silica at 5%, 10% and 20% volume percentages. The samples were investigated in terms of their density, apparent porosity, tensile strength in three-point bending test, compressive strength, thermal shock and mineralogical composition. The use of 20% silica resulted in an increase in the formation of cristobalite, higher packing of granular mixtures, and consequently, an improvement in the tensile strength and compression strength of the samples. However, the material that was most successful in increasing the mechanical strength without decreasing the thermal shock strength was the sample processed with 10% clay replacement by silica from rice husk.
Ederli Marango - One of the best experts on this subject based on the ideXlab platform.
-
development of Refractory Ceramics from residual silica derived from rice husk ash and steel fibres
Ceramics International, 2017Co-Authors: N P Stochero, Ederli Marango, A S Nunes, Marco Antonio Durlo TieAbstract:Abstract Despite their high hardness and thermal stability, Refractory Ceramics have a tendency to undergo failure due to fatigue and thermal shock. In this study, the effects of rice husk silica and steel fibres on the mechanical and thermal properties of Refractory ceramic materials were investigated. Samples were fabricated by replacing kaolin clay with 20% rice husk silica and 3%, 6% or 9% steel fibres in volume percentages. These specimens were analysed for their mineralogical composition, density, apparent porosity, tensile strength in a three-point bending test, thermal shock and microstructural analysis by scanning electron microscopy. For materials with silica and clay, a reduction in porosity and increase in mechanical resistance was observed. Ceramics with 9% steel fibre had the greatest ductility, while materials with 3% and 6% steel fibre presented the highest resistance against thermal shock.
-
development of Refractory Ceramics from residual silica derived from rice husk ash
Ceramics International, 2017Co-Authors: F Z Sobrosa, N P Stochero, Ederli Marango, Marco Antonio Durlo TieAbstract:Abstract Rice husk has been used as a thermal energy source for electricity generation, resulting in the formation of silica from rice husk as a by-product. This research aims to develop Refractory ceramic materials by replacing kaolin clay with rice husk silica at 5%, 10% and 20% volume percentages. The samples were investigated in terms of their density, apparent porosity, tensile strength in three-point bending test, compressive strength, thermal shock and mineralogical composition. The use of 20% silica resulted in an increase in the formation of cristobalite, higher packing of granular mixtures, and consequently, an improvement in the tensile strength and compression strength of the samples. However, the material that was most successful in increasing the mechanical strength without decreasing the thermal shock strength was the sample processed with 10% clay replacement by silica from rice husk.
F H Sto - One of the best experts on this subject based on the ideXlab platform.
-
statistical approach for minimizing cracks in combined flame spraying and laser surface modification of Refractory Ceramics
Journal of The European Ceramic Society, 2004Co-Authors: F H StoAbstract:Abstract Combined flame and CO2 laser spraying for surface modification of 20 wt.% Cr2O3–80 wt.% Al2O3 has been developed for improved surface performance of alumina-based Refractory bricks. In this paper, the crack length per unit surface area and crack density of single treated tracks with respect to the three process parameters: laser irradiation intensity, powder feed rate and workpiece traverse velocity, have been investigated by employing a statistical approach involving statistical experiment design and regression analysis. It was found that the present statistical approach was effective for investigating the role of the process parameters on the crack length per unit surface area. Reducing both the powder feed rate and the workpiece traverse velocity could reduce the occurrence of cracks in the treated tracks. The former corresponded to decreasing the α-Al2O3 content in the treated tracks, and the latter to decreasing the cooling and solidifying rate of the melt pool.
-
crystallographical analysis of surface layers of Refractory Ceramics formed using combined flame spray and simultaneous laser treatment
Journal of The European Ceramic Society, 2004Co-Authors: F H StoAbstract:Abstract The crystalline characteristics of the surface layers of an alumina-based Refractory ceramic, prepared using a novel combined flame spraying and laser melting method, have been investigated using X-ray diffraction and the Rietveld method. The results have indicated that 20% Cr 2 O 3 by weight added to Al 2 O 3 powder retards the metastable γ-Al 2 O 3 to α-Al 2 O 3 phase transition during flame spraying. The mullite crystals grew preferentially along the [111] direction for surface layers prepared by laser melting only or by the combined process using pure Al 2 O 3 powder as the feedstock for flame spraying. In the latter case, the surface layer contained more alumina-rich mullite and more crystalline cristobalite than the surface layer prepared by laser melting. However, using a composite powder of 20% Cr 2 O 3 and 80% Al 2 O 3 by weight as feedstock in the combined process, not only did the preferred orientation of the mullite grains change to the [220] direction, but, also, the amount of SiO 2 incorporated in the mullite crystals was closer to that for stoichiometric mullite.
-
combined laser and flame surface coating of Refractory Ceramics phase and microstructural characteristics
Thin Solid Films, 2004Co-Authors: F H StoAbstract:Abstract Hybrid flame spraying, combined with CO 2 laser irradiation, has been developed to improve the structural integrity and performance of alumina coatings deposited on an alumina-based Refractory substrate. The alumina coatings, over 400 μm in thickness, were prepared using various process parameters. The phases and microstructures of the coatings were investigated with X-ray diffraction, optical microscopy, scanning electron microscopy and an image analysis method. It was found that, with the hybrid spraying, the extent of densification was increased and the β-Al 2 O 3 content of the coatings was decreased, with increase in laser power level and decrease in workpiece traverse velocity. A larger laser beam size could decrease and, even, eliminate the intermediate metastable γ-Al 2 O 3 , δ-Al 2 O 3 and θ-Al 2 O 3 phases in the corresponding coating. The above results suggest that the β-Al 2 O 3 content of the coatings should reflect the degree of melting of the starting alumina powder. A larger laser beam would be useful for decreasing the cooling and solidifying rates of the melted alumina.
-
multi layered surface coatings of Refractory Ceramics prepared by combined laser and flame spraying
Surface & Coatings Technology, 2004Co-Authors: F H StoAbstract:Hybrid laser-flame spraying provides a new opportunity for depositing multi-layered surface coatings with a range of densities and microstructures. In the present study, multi-layered zirconia-alumina coatings of various densities and thicknesses were applied onto an alumina-based Refractory substrate by the hybrid laser-flame spraying method, using several sets of process parameters. The microstructures and porosity data for the coatings were characterized by scanning electron microscopy and the image analysis method. The results showed that the combined laser and flame spraying technique was a practicable approach for preparing multi-layered coatings. The relationships between the coating microstructure, process parameters and types of powder materials are discussed.
F Z Sobrosa - One of the best experts on this subject based on the ideXlab platform.
-
development of Refractory Ceramics from residual silica derived from rice husk ash
Ceramics International, 2017Co-Authors: F Z Sobrosa, N P Stochero, Ederli Marango, Marco Antonio Durlo TieAbstract:Abstract Rice husk has been used as a thermal energy source for electricity generation, resulting in the formation of silica from rice husk as a by-product. This research aims to develop Refractory ceramic materials by replacing kaolin clay with rice husk silica at 5%, 10% and 20% volume percentages. The samples were investigated in terms of their density, apparent porosity, tensile strength in three-point bending test, compressive strength, thermal shock and mineralogical composition. The use of 20% silica resulted in an increase in the formation of cristobalite, higher packing of granular mixtures, and consequently, an improvement in the tensile strength and compression strength of the samples. However, the material that was most successful in increasing the mechanical strength without decreasing the thermal shock strength was the sample processed with 10% clay replacement by silica from rice husk.