The effect of pressure tuning on the structure and mechanical properties of high-entropy carbides

High-purity (Ta _0.2Nb _0.2Hf _0.2Zr _0.2Ti _0.2 )C high-entropy ceramics are successfully synthesized using high-pressure solid-phase reactions. The high-entropy phase formation route and the effect of pressure tuning on the structural and mechanical properties of the ceramics are systematically investigated. An interesting process is observed whereby a double phase high-entropy carbide is formed, followed by the defusing of one phase into another, and the eventual formation of a high-entropy phase. Moreover, an abnormal, pressure-induced enhancement of the bulk modulus and strength is observed, resulting from the crystal plane distortion in high-entropy carbides. These results reflect the unusual lattice distortion effects of continuous, pressure-induced tuning on the structure and properties of high-entropy carbides.