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Publikācija: Influence of Raw Materials Ratio and Sintering Temperature on the Properties of the Refractory Mullite-Corundum Ceramics

Publication Type Scientific article indexed in ERIH database, in INT1 or INT2 category journals
Funding for basic activity Unknown
Defending: ,
Publication language English (en)
Title in original language Influence of Raw Materials Ratio and Sintering Temperature on the Properties of the Refractory Mullite-Corundum Ceramics
Field of research 2. Engineering and technology
Sub-field of research 2.5 Materials engineering
Authors Ludmila Mahņicka-Goremikina
Keywords Alumina, Kaolin, Mullite-corundum, Porous refractory ceramics
Abstract The alumosilicate ceramics with mullite crystalline phase are used in various branches of science and technique. The mullite refractory ceramics with high porosity serve as a heat insulator and as well as a constructional materials. The purpose of the work was to sinter high porosity ceramic and to increase the quantity of mullite phase in this mullite, mullite-corundum ceramics. Two types of compositions were prepared during the experiment. The first type was the compositions with commercial alumina and silica oxides. The second type was from mixing these oxides with 10, 20 and 30 wt% of kaolin. In all samples the Al2O3 and SiO2 were in 2.57:1 ratio, because that was conformed to mullite stechiometric compositions (3Al2O3.2SiO2). The types of alumina oxides were α-Al2O3 (d50=4µm) and γ-Al2O3 (d50=80µm). Ratios of α-: γ-Al2O3 were (1:1) or (1:3). The porous materials were prepared by slip casting of suspension of raw materials. The aluminium paste (0.18 wt%) was used as a pore former. Water content in the suspensions was 30-47 wt%. Pore formation occurred as a result of hydrogen formation in chemical reaction between aluminium paste and water. The samples were sintered at the temperature of 1650°C and 1750°C for one hour. The increasing amount of kaolin, α-: γ-Al2O3 at the ratio (1:3) and sintering at the highest temperature raised the quantity of mullite phase. The mullite phase began to dominate over the corundum phase.
Hyperlink: http://waset.org/publications/12805 
Reference Mahņicka-Goremikina, L. Influence of Raw Materials Ratio and Sintering Temperature on the Properties of the Refractory Mullite-Corundum Ceramics. World Academy of Science, Engineering and Technology: International Journal of Chemical, Molecular, Nuclear, Materials and Metallurgical Engineering, 2012, Vol.6, No.3, pp.404-409. ISSN 2010-376X. e-ISSN 2010-3778.
ID 13558