Investigation on Fabrication, Microstructure, and Mechanical Properties of (TiZrNbV) C-SiC High Entropy Composite Ceramics
摘要
High-entropy carbide ceramics are promising for extreme environments due to their exceptional hardness and thermal stability, yet their relatively high brittleness hinders further application. This study balanced the hardness and toughness of the high-entropy ceramics by doping with the second phase SiC particles. The (TiZrNbV)C-SiC high-entropy composite ceramics were synthesized via fast hot-press sintering, while (TiZrNbV)C high-entropy ceramics served as a comparative control. The results indicate that within an extremely short timeframe, the (TiZrNbV)C-SiC high-entropy composite ceramic achieved an excellent relative density of 98.71%, resulting from the incorporation of the second phase. The mechanical property test results indicate that the incorporation of the second phase significantly enhances hardness, toughness, and wear resistance. The hardness and fracture toughness of the high-entropy composite ceramic are 33.00 ± 0.52 GPa and 4.57 ± 0.62 MPa m1/2, respectively. While the H3/E2 increased by 27.6% to reach 0.2162 GPa. Doping of the SiC phase inhibits crack propagation and reduces the brittleness of the ceramic. Under a 9 N load, the (TiZrNbV)C-SiC exhibits an exceptionally low specific wear rate of 1.72 × 10-6 mm3 N-1 m-1, compare to the (TiZrNbV)C. This work provides a viable design strategy for simultaneously enhancing the toughness and wear resistance of high-entropy ceramics.