DEVELOPMENT OF SYNTHESIS METHOD FOR SINGLE-PHASE HIGH-ENTROPY CERAMIC MATERIALS WITH A HIGH DEGREE OF CHEMICAL HOMOGENEITY ON THE EXAMPLE OF EQUIATOMIC HIGH-ENTROPY CARBIDE (TIZRHFTANB)C

The paper presents the synthesis results of high-entropy carbides using pre-mechanically alloyed powders of high-entropy alloys (HEA). The use of HEA as a starting material for synthesizing high-entropy ceramics allows obtaining one-phase and chemically homogeneous high-entropy carbides due to preliminary mixing of metals at the atomic level, accompanied by the formation of a single-phase solid solution. We showed that in the process of sintering a mechanical mixture of pre-mechanically alloyed HEA powders with graphite at temperatures of about 1600°C, high-entropy carbide with the chemical formula MeC and space group Fm-3m is formed. However, according to the phase composition and microstructure analysis, inclusions are formed in the form of zirconium-hafnium oxide and a transition layer between oxide inclusions and the main carbide phase. Raising the temperature up to 2000°C produces a single-phase and chemically homogeneous high-entropy carbide (TiZrHfTaNb)C.