Abstract A kind of B4C/SiC composite ceramic toughened by graphene platelets and Al was fabricated by spark plasma sintering. The effects of graphene platelets and Al on densification, microstructure and mechanical properties were studied. The sintering temperature was decreased about 125–300 °C with the addition of 3–10 wt% Al. Al can also improve fracture toughness but decrease hardness. The B4C/SiC composite ceramic with 3 wt%Al and 1.5 wt% graphene platelets sintered at 1825 °C for 5 min had the optimal performances. It was fully densified, and the Vickers hardness and fracture toughness were 30.09 ± 0.39 GPa and 5.88 ± 0.49 MPa m1/2, respectively. The fracture toughness was 25.6% higher than that of the composite without graphene platelets. The toughening mechanism of graphene platelets was also studied. Pulling-out of graphene platelets, crack deflection, bridging and branching contributed to the toughness enhancement of the B4C-based ceramic.

中文翻译：

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放电等离子烧结石墨烯薄片增韧碳化硼复合陶瓷的组织与性能

摘要 采用放电等离子烧结法制备了一种石墨烯薄片和铝增韧的B4C/SiC复合陶瓷。研究了石墨烯薄片和铝对致密化、微观结构和机械性能的影响。添加 3-10 wt% Al 后，烧结温度降低了约 125-300 °C。Al还可以提高断裂韧性但降低硬度。含有 3 wt% Al 和 1.5 wt% 石墨烯薄片的 B4C/SiC 复合陶瓷在 1825°C 下烧结 5 分钟具有最佳性能。充分致密化，维氏硬度和断裂韧性分别为 30.09±0.39 GPa 和 5.88±0.49 MPa m1/2。断裂韧性比没有石墨烯片的复合材料高 25.6%。还研究了石墨烯片晶的增韧机制。石墨烯片的拉出，