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

作者：Liansen Xia, Shun Dong, Jianqiang Xin, Kaixuan Gui, Peitao Hu, Yongshuai Xie, Dongdong Yang, Xinghong Zhang, Yanchun Zhou · 发表于：Journal of Advanced Ceramics · 年份：2023 · DOI：10.26599/jac.2023.9220755 · 被引用次数：43 · 研究领域：Advanced materials and composites、High Entropy Alloys Studies、Metal and Thin Film Mechanics

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 to realize the green and low-cost synthesis of high-quality multi-anionic HE carbonitride UHTC powders and prepare bulk ceramics with excellent mechanical properties still faces great challenges. In this work, a green, low-cost and controllable preparation process of (Ti 0.2 Zr 0.2 Hf 0.2 Nb 0.2 Ta 0.2 )C x N 1- x powders is achieved by a sol-gel combined with carbothermal reduction/nitridation method for the first time. The as-synthesized (Ti 0.2 Zr 0.2 Hf 0.2 Nb 0.2 Ta 0.2 )C x N 1- x powders possess high compositional uniformity and controllable particle size. In addition, the obtained bulk ceramics prepared at 1800 ℃ exhibit a superior fracture toughness of 5.39±0.16 MPa·m 1/2 , high nanohardness of 35.75±1.23 GPa, elastic modulus of 566.70±8.68 GPa and flexural strength of 487±41 MPa. This study provides a feasible strategy for preparing high-performance HE carbonitride ceramics in a more environmentally friendly and economical manner.