High-entropy diboride: A novel high-temperature self-lubricating ceramic with enhanced mechanical and tribological properties

作者：Jicheng Li, Yunfeng Su, Shuna Chen, Hengzhong Fan, Xiande Zheng, Qiuan Sun, Junjie Song, Litian Hu, Yongsheng Zhang · 发表于：Journal of Advanced Ceramics · 年份：2025 · DOI：10.26599/jac.2025.9221085 · 被引用次数：26 · 研究领域：High Entropy Alloys Studies、Metal and Thin Film Mechanics、High-Temperature Coating Behaviors

Ceramic-based lubrication materials are among the best choices for solving high-temperature load-bearing and lubrication problems. However, traditional ceramics achieve self-lubrication by adding lubricating phases, which often leads to a significant degradation of mechanical properties, severely limiting their engineering applications. Benefiting from the excellent high-temperature mechanical and lubrication potential of the novel high-entropy borides, the present work innovatively proposed the strategy of using high-entropy ceramics' own components to provide lubrication functions and successfully designed and prepared a novel high-entropy (Ti 0.2 V 0.2 Nb 0.2 Ta 0.2 Mo 0.2 )B 2 based on the tribological element design principles. The material achieves synergistic enhancement of both mechanical and tribological performances. Its microhardness, fracture toughness, and flexural strength are up to 23.8±0.9 GPa, 5.4±0.3 MPa·m 1/2 , and 415±17 MPa, respectively. Furthermore, compared with the conventional single-phase ceramics, the high-entropy (Ti 0.2 V 0.2 Nb 0.2 Ta 0.2 Mo 0.2 )B 2 with Al 2 O 3 balls as the mating partner demonstrates exceptional overall tribological properties across a wide temperature range. Notably, the friction coefficient is as low as 0.12±0.01 at 1000 ℃, while the wear rate maintains at a low level ((8.8±0.7)×10 -5 mm 3 /Nm). This outstanding high-temperature tribological performance is primarily attributed to the novel high-temperature solid-liquid...