Evaluation of the porogenic behavior of aluminum hydroxide particles of different size distributions in castable high-alumina structures
| Autor: | Adriane D.V. Souza, Rafael Salomão |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
010302 applied physics
Materials science Metallurgy Sintering 02 engineering and technology Thermal treatment 021001 nanoscience & nanotechnology Microstructure 01 natural sciences Casting Chemical engineering visual_art 0103 physical sciences Materials Chemistry Ceramics and Composites visual_art.visual_art_medium CERÂMICA Particle Ceramic 0210 nano-technology Porosity Gibbsite |
| Zdroj: | Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual) Universidade de São Paulo (USP) instacron:USP |
| ISSN: | 0955-2219 |
| DOI: | 10.1016/j.jeurceramsoc.2015.11.019 |
| Popis: | The combination of Al2O3 and Al(OH)3 produces high refractoriness porous structures. The evolution of these ceramics during the first heating is a competition between pore generation by Al(OH)3 dehydroxilation, and densification by sintering. Previous studies have reported the size of Al(OH)3 particles affect both events. In this study, we evaluate the porogenic behavior of three grades of α-Al(OH)3 (gibbsite) of different average particle sizes (0.9, 10 and, 107 μm). The particles were thermally treated (300–1500 °C) for the investigation of changes in their physical properties and microstructures. Amounts of 67.5 vol% of each grade were added to aqueous castable alumina suspensions. After rheological tests and casting, the sintered samples (1100–1500 °C) were tested for porosity, pore size, and strength and examined by electron microscopy. The particles of the three grades exhibited similar evolution during thermal treatment. When they were added to the alumina matrix, structures of different porosity and strength were obtained. |
| Databáze: | OpenAIRE |
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