Spontaneous pulverisation of Al4C3containing MAX bulk ceramics at room temperature

The deleterious effect of Al4C3 on the performance of MAX ceramics has not attracted much attention. In the present study, Al4C3 containing Cr2Al(Si)C and SiC/Cr2AlC 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 Al4C3 with moisture is held responsible for the disintegration of Al4C3 containing MAX ceramics. Preventive measures to avoid the formation of Al4C3 upon preparing MAX ceramics were herein proposed.