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

In this study, fast hot-pressing sintering and the power of B4C and 1/3/5/7 wt% Al2O3 were used to make B4C-Al2O3 composite ceramics at 2000°C and 30 MPa. The toughening mechanism was thoroughly examined, and the impact of Al2O3 content on the microstructures and mechanical characteristics of B4C-Al2O3 composite ceramics was examined. The comprehensive mechanical properties of B4C-Al2O3 composite ceramics were optimized by adding 3 wt% Al2O3, the relative density, flexural strength, fracture toughness, and Vickers hardness reached 99.38%, 616.2 MPa, 5.45 MPa∙m1/2, and 35.91 GPa, respectively. The strengthening mechanism of B4C-Al2O3 composite ceramics is that grain refinement and grain boundary movement are hindered by second-phase particles. And the toughening mechanism is crack deflection and Al2O3 grain cracking.