High‐entropy boride ceramic cutting tools by SPS‐HF dual sintering: Preparation process, composition, and properties

Abstract High‐entropy boride (HEB) ceramics demonstrate significant potential for cutting tool applications, yet conventional synthesis methods face challenges in achieving full densification and optimal mechanical performance. (Mo 0.2 Zr 0.2 Ta 0.2 Nb 0.2 Ti 0.2 )B 2 HEB ceramics were prepared using the spark plasma sintering‐high‐frequency (SPS‐HF) dual sintering method. The optimal mechanical properties of the HEB ceramic cutting tool materials were achieved at a sintering temperature of 1750°C. Compared with the HEB ceramic tool material without Al 2 O 3 (HEB0), the HEB ceramic tool material containing 3 wt% Al 2 O 3 (HEB3A) exhibited improved mechanical properties. The Vickers hardness and flexural strength of HEB3A were 20.07 GPa and 492.85 MPa, representing increases of 2.87% and 17.28%, respectively, compared to HEB0. The HEB3A tool achieved a cutting distance of 1000 m and a coefficient of friction of 0.62 during dry cutting tests on 45 steel, representing a 66.67% increase and an 11.29% reduction, respectively, compared to the HEB0 tool. The results indicate that the addition of Al 2 O 3 improves the cutting performance of HEB ceramic tools. This work shows that the HEB‐based ceramics with high hardness, high toughness, and high flexural strength have potential applications in the field of cutting tools.