DEVELOPMENT OF CERAMIC COMPOSITES FROM MIXTURE OF ALUMINA AND CERAMIC PRECURSOR POLYMER POLY (SILSESQUIOXANE) / Desenvolvimento de compósito cerâmico a partir de mistura de alumina e polímero pecursor  cerâmico polissilsesquioxano

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Processing of ceramics materials, by polymer precursors pyrolysis, has been intensively researched over the past decades, due to advantages that this path provides, such as: lower temperature process compared to conventional techniques; structure control at molecular level; synthesis possibility of a wide range of ceramic compounds; obtaining parts with dimensions of the final product etc. The active filler controlled polymer pyrolysis (AFCOP) process, enables the synthesis of ceramic composites, by reaction between added filler (oxides, metals, intermetallic etc.) and solid and gaseous products, from polymer decomposition. In this study, based on this process, samples of alumina, with addition of 10 and 20 mass% of poly silsesquioxane polymer precursor, were manufactured. These samples were pyrolyzed at 900 °C and thermal treated at temperatures of 1100, 1300 and 1500 °C. The samples were characterized for bulk density, porosity and hardness, after each stage of thermal treatment. Structural transformations were analyzed by X-ray diffraction, scanning electron microscopy and infrared spectroscopy. Samples treated until 1300 °C resulted in composites of alumina and silicon oxicarbide, while those treated at 1500 °C, formed composites of mullite and alumina. The samples with 20% of polymer added started to densify around 800°C and high retraction rate was observed at 1400°C.

ASSUNTO(S)

compósito alumina compósito pirólise polissilsesquioxano polissilsesquioxano pirólise alumina

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