The influence of nano alumina additions on the coefficient of thermal expansion of a LZS glass–ceramic composition
| Autor: | A.P. Novaes de Oliveira, Rosa Giménez Moreno, M.I. Nieto, Sabrina Arcaro |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
010302 applied physics
Zirconium Materials science Glass-ceramic Process Chemistry and Technology chemistry.chemical_element Sintering 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Thermal expansion Surfaces Coatings and Films Electronic Optical and Magnetic Materials law.invention chemistry law 0103 physical sciences Materials Chemistry Ceramics and Composites Relative density Particle size Crystallization Composite material 0210 nano-technology Frit |
| Zdroj: | Ceramics International. 42:8620-8626 |
| ISSN: | 0272-8842 |
| DOI: | 10.1016/j.ceramint.2016.02.093 |
| Popis: | In this work a 19.58Li 2 O·11.10ZrO 2 ·69.32SiO 2 (mol%) glass–ceramic matrix was prepared and milled in order to determine its coefficient of thermal expansion (CTE) and to study how it is influenced by the addition of nanosized Al 2 O 3 particles (1–5 vol%) and submicrometric Al 2 O 3 particles (5 vol%). Comminution studies from the LZS parent glass frit showed that a powder with an adequate particle size (3.5 µm) is achieved after 120 min of dry milling followed by a second step of 60 h wet milling. The obtained LZS glass–ceramic samples (fired at 900 °C/30 min) showed an average relative density of ∼98% with zirconium silicate and lithium disilicate as main crystalline phases. Prepared composites with 1, 2.5 and 5 vol% of nanosized Al 2 O 3 and 5 vol% submicrometric Al 2 O 3 showed average relative densities varying from 97% to 94% as the alumina content increased. The formation of β-spodumene in the obtained composites leads to reduce the CTEs, whose values ranged from 9.5 to 4.4×10 −6 °C −1 . Composites with 5% nanosized alumina showed a CTE lower than that of the equivalent formulation with submicrometric alumina. |
| Databáze: | OpenAIRE |
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