High-performance B4C-Al2O3 composite ceramics fabricated via fast hot-pressing sintering

In this study, fast hot-pressing sintering and the power of B 4 C and 1/3/5/7 wt% Al 2 O 3 were used to make B 4 C-Al 2 O 3 composite ceramics at 2000°C and 30 MPa. The toughening mechanism was thoroughly examined, and the impact of Al 2 O 3 content on the microstructures and mechanical characteristics of B 4 C-Al 2 O 3 composite ceramics was examined. The comprehensive mechanical properties of B 4 C-Al 2 O 3 composite ceramics were optimized by adding 3 wt% Al 2 O 3 , the relative density, flexural strength , fracture toughness, and Vickers hardness reached 99.38   %, 616.2 MPa, 5.45 MPa∙m 1/2 , and 35.91 GPa, respectively. The strengthening mechanism of B 4 C-Al 2 O 3 composite ceramics is that grain refinement and grain boundary movement are hindered by second-phase particles. And the toughening mechanism is crack deflection and Al 2 O 3 grain cracking.