Wetting behaviour of a Cu/Ti 3 SiC 2 system was investigated by the sessile drop technique under a vacuum atmosphere. Contact angles between Cu and Ti 3 SiC 2 changed from 95 to 15u as temperatures increased from 1089 to 1270uC. Two distinct reaction layers consisting of different contents of Cu, TiC x , Ti 3 SiC 2 and Cu x Si y intermetallics were formed at the interface of Cu and Ti 3 SiC 2 . The formation of the interface layers contributes to the improvement of the wettability of the system. The dissolution of Si from theTi 3 SiC 2 into the molten Cu at high temperature plays a dominant role in the wetting behaviour of Cu/Ti 3 SiC 2 systems.

The deleterious effect of Al 4 C 3 on the performance of MAX ceramics has not attracted much attention. In the present study, Al 4 C 3 containing Cr 2 Al(Si)C and SiC/Cr 2 AlC ceramics have been prepared. It was found that spontaneous pulverisation of the as synthesised samples took place at room temperature after exposure in air and water for various durations. Volume expansion induced by the interaction of Al 4 C 3 with moisture is held responsible for the disintegration of Al 4 C 3 containing MAX ceramics. Preventive measures to avoid the formation of Al 4 C 3 upon preparing MAX ceramics were herein proposed.

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