INFILTRATION OF ZIRCONIUM DIBORIDE BY ICVI IN POROUS MATERIALS

This paper presents the results of an infiltration study, by ICVI, of zirconium diboride into three-dimensional porous preforms to make C/Zr B2 composites. An experimental design based on a model substrate shows the level and the sense of the influence of the parameters on the qua lity and kinetics of infiltration. Dilution of the reactants (BCl3, Zr Cl4, H-2) by helium improves infiltration quality. Application of the results to the densification of a real porous preform with small dimen sions shows the possibility of densification and its great sensitivity to the variation of the most important experimental parameters (total flux, temperature). The infiltration process shows that larger prefor ms could be densified by this method. (C) 1997 Elsevier Science Limite d.