Synthesis and thermal stability of Cr2AlC

A new reaction route with AlCr2 and C as starting materials has been developed to produce Cr2AlC. A Cr2AlC bulk ceramic was achieved by hot pressing the AlCr2 and C powders at 1400 °C with 20 MPa for 1 h in Ar. The mechanism to form Cr2AlC in a temperature range of 1050–1400 °C was studied. It was confirmed that Cr2AlC is formed directly by a reaction between C and AlCr2. The reaction process, phase composition and microstructure were characterized with differential thermal analysis, X-ray diffractometry and scanning electron microscopy. The produced Cr2AlC ceramic is stable up to 1500 °C in an Ar atmosphere, but decomposes into Al8Cr5 and Cr23C6 above 1500 °C.