Wetting characteristics and interfacial reaction of liquid aluminium on hot-pressed boron nitride substrate

The wettability and interfacial reaction between liquid aluminium and hot-pressed (HP) boron nitride were investigated by the sessile drop method, electron probe microanalysis and X-ray diffraction. The results show that the interfacial reaction and diffusion of liquid aluminium on the ceramic surface promote wetting of the ceramic. Interface analysis shows that liquid aluminium can react intensely with HP boron nitride at high temperature, and there exists a nitrogen-rich layer near the aluminium and a pile-up of boron near the ceramic. After the experiment at 1435 K, the surface of the reaction layer was completely covered by aluminium nitride.