Numéro
J. Phys. IV France
Volume 03, Numéro C7, Novembre 1993
The 3rd European Conference on Advanced Materials and Processes
Troisiéme Conférence Européenne sur les Matériaux et les Procédés Avancés
Page(s) C7-1927 - C7-1930
DOI http://dx.doi.org/10.1051/jp4:19937308
The 3rd European Conference on Advanced Materials and Processes
Troisiéme Conférence Européenne sur les Matériaux et les Procédés Avancés

J. Phys. IV France 03 (1993) C7-1927-C7-1930

DOI: 10.1051/jp4:19937308

Corrosion of ceramic matrix composites

T. SCANU1, 2 and Ph. COLOMBAN1, 2

1  ONERA-OM, BP. 72, 92322 Châtillon, France
2  LASIR, CNRS, 2 rue Henri Dunant, 94320 Thiais, France


Abstract
Air stable ceramic matrix composites are promising for thermostructural applications such as aircraft engine parts. Turbine parts are subject to both sulphuric acid and sodium molten salts corrosion due to sulphate traces in engine fuel and to the NaCl air content. The chemical stability is a very important criterion but this point has not received much attention to date. We report here a study of acidic and sodium corrosion of various aluminosilicate matrices : LAS matrices (Li2OAl2O32-6SiO2, nP2O5) in the amorphous, β eucryptite and β spodumene forms, BAS matrix (BaOAl2O32SiO2) in the form of monoclinic and hexagonal celsian, NASICON matrix (Na3Zr2Si2PO12) and mullite matrix. Microstructure damages and ion exchange have been analysed by X-ray diffraction, IR absorption, scanning electron microscopy and Raman microprobe. Drastic corrosion is observed for β spodumene containing composites with the formation of strong hydrogen bond or with the cell expansion due to Li/NA+ exchange. Medium acidic attack occurs for glassy LAS, β eucryptite, BAS and NASICON matrix composites. On the other hand, β eucryptite, NASICON and monoclinic celsian resist to alkaline melts. Mullite matrix composites are never corroded.



© EDP Sciences 1993