Fabrication of multi-anionic high-entropy carbonitride ultra-high-temperature ceramics by a green and low-cost process with excellent mechanical properties

As a new category of ultra-high temperature ceramics (UHTCs), multi-anionic high-entropy (HE) carbonitride UHTCs are expected to have better comprehensive performances than conventional UHTCs. However, how realize the green and low-cost synthesis high-quality HE UHTC powders prepare bulk with excellent mechanical properties still faces great challenges. In this work, green, controllable preparation process (Ti0.2Zr0.2Hf0.2Nb0.2Ta0.2)CxN1-x is achieved by sol-gel combined carbothermal reduction/nitridation method for first time. The as-synthesized possess high compositional uniformity particle size. addition, obtained prepared at 1800 ℃ exhibit superior fracture toughness 5.39±0.16 MPa·m1/2, nanohardness 35.75±1.23 GPa, elastic modulus 566.70±8.68 GPa flexural strength 487±41 MPa. This study provides feasible strategy preparing high-performance in more environmentally friendly economical manner.