Thermal explosion synthesis of Cr2AlB2 materials

Abstract Ternary conductive ceramic Cr2AlB2 phase has been widely studied because of its unique physical and chemical properties. However, the preparation of conventional synthetic Cr2AlB2 requires expensive raw materials or higher equipment cost, which is not conducive to its synthesis and promotion. Hence, we synthesized high-content Cr2AlB2 by thermal explosion reaction, a technology with low-energy consumption. Cr2AlB2 was synthesized by thermal explosion reaction from Cr/Al/B mixed powders. The effects of different ignition materials and diamond additive on Cr2AlB2 synthesis were studied systematically. Results showed that the Cr/Al/B system did not undergo a thermal explosion reaction. An aluminothermic reaction between Al and Cr2O3 occurred by introducing a small amount of Cr2O3. The main phase of the thermal explosion products of the Cr/Al/B/Cr2O3 green body was CrB. The addition of an appropriate amount (7.5 % and 10 %) of diamond in the raw material can obviously promote Cr2AlB2 synthesis. The main phases of the product were Cr2AlB2 and CrB. The samples were composed of a large number of fine Cr2AlB2 lath grains. Finally, the mechanism of Cr2AlB2 formation by thermal explosion reaction was proposed.