Surface densification of porous ZrC by a laser process
Résumé
Thin films of 100%-dense zirconium carbide, ZrC, on top of ca. 30%-porous ZrC are obtained by using an ytterbium-doped fibre laser under argon atmosphere. It is shown experimentally and theoretically that oxidation into zirconia or oxycarbide is completely avoided at the working temperature of at least 3420 ◦C. This type of highly refractory materials – dense at the surface and porous in the bulk – could be used in high temperature applications where both diffusion and ained by thermal carboreduction of oxides.