Corrosion behavior of pyrocarbon coatings exposed to Al2O3-SiO2 gels containing ammonium nitrate

摘要

The corrosion behavior of pyrocarbon (PyC) coatings exposed to Al2O3-SiO2 gels containing ammonium nitrate (AN) was investigated. The formation of nitrogen oxides during the decomposition of AN could enable the oxidation of PyC at relatively low temperature. After corrosion by the gels, severe attack was observed and the surface roughness of the coatings increased remarkably. The degree of crystallization decreased while that of disorder increased in PyC. Finally, PyC coatings were introduced into threedimensional all-oxide fiber-reinforced composites. We found that the resulting porous coatings were favorable to the fiber/matrix debonding, thereby contributing to the performance improvement. (C) 2015 Elsevier Ltd. All rights reserved.