Synthesis of fine and high purity Cr2AlC powders by novel method

Cr2AlC powders using Cr/Al/C and Cr/Al/Cr3C2 systems as raw materials were successfully synthesised by a microwave hybrid heating method for the first time. The mixtures of Cr, Al and graphite or Cr3C2 with different molar ratios were used to investigate the formation of Cr2AlC phase. For Cr/Al/C with the molar ratios of 2:(1.0-1.2): 1 system, Cr2AlC with a small amount of Cr7C3 and Cr2Al was synthesised at 1000 degrees C for 3 min, and the average particle size was, similar to 1 mu m. For Cr/Al/Cr3C2 with the molar ratio of 1:2:1 system, high purity Cr2AlC powders was synthesised at 1000 degrees C for 3 min, and the average particle size was, <1 mu m. The synthesis of high purity Cr2AlC powders for short time was attributed to the combination of the hybrid heating effect and the introduction of Cr3C2 as carbon source. Microwave hybrid heating is a promising method for the preparation of various other MAX phases.