Processamento de compósitos C-SiCxOy via pirólise polimérica para aplicações termo estruturais / Processing of SICxOy composites by polymeric pyrolysis to thermo-structural applications

AUTOR(ES)
DATA DE PUBLICAÇÃO

2000

RESUMO

Composites are heterogeneous materials made by one or more types of reinforcements, disposed or not in a definied direction, which is dispersed in a ceramic, metallic or polymeric matrix. The combination of these materials permits that the intrinsic properties from each one of the components contribute in the formation of a new material having characteristics adjusted and superior to each one of the individual components. The composites can be divided in: a)low application temperatures (< 300 §C), e. g. polymeric composites and, b)high application temperaturs (>1000 §C), mainly composites having ceramic and mettalic matrices. The composites made by using ceramic matrices can be processed essentially by two methods: 1)Liquid phase, as example polymer pyrolyse; 2)Gaseous phase, as example chemical vapour infiltration (CVI). The present work has a main objective the obtaintion of a composite starting from carbon fibres and a silicon carbide-based ceramic matrix (SiC)using a polymer precursors as a starting material. This processing route seems to be promising due to easy processing. The mateials obtained in this work were characterized by microscopy and dynamic-mechanical testing, which have been proved of usefulness to the characterization of the material during the processing steps. A C/SiC composite having bulk density of 1,70 g/cm3, flexural strength of 57 MPa, and flexural modulus of 24 GPa was obtained. Dynamic mechanical properties were also measured in carbon fibre reinforced carbon composites and the results showed correlation with the type of carbon fibre in their manufacture, with the fibre volume fraction and with the final heat temperature treatment.

ASSUNTO(S)

fibras de carbono propriedades elásticas pirólise vibration measurement engenharia e tecnologia espacial propriedades mecânicas mechanical properties compósitos de matriz cerâmica carbon fibrs pyrolysis elastic properties ceramic matrix composites medida de vibração

ACESSO AO ARTIGO

Documentos Relacionados