Wetting and non-wetting behaviour of silicon carbide grain boundaries

Abstract

Silicon carbide (SiC) grain boundaries have been observed to be free from intergranular films. On the basis of equilibrium film thickness calculations, it has been proposed elsewhere that because SiC has very high refractive index, the attractive forces are very large and thin amorphous films cannot exist at SiC grain boundaries. However, in our studies, we have observed film-free grain boundaries together with grain boundaries containing intergranular films. Possible reasons for the welting and non-wetting behaviour of SiC grain boundaries are briefly discussed.