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基于反应烧结SiC制备出相对密度较高的SiC/B4C复合材料,并探讨原料中C含量对SiC/B4C复合材料物相、显微结构、体积密度、力学性能的影响。结果表明,SiC/B4C复合材料的相组成为B4C、SiC、Si、B13C2和B12.97Si0.03C2。SiC/B4C复合材料的显微组织为:SiC相和B4C相均匀分布,游离Si填充在B4C相和SiC相的空隙处,且形成了连续相。随着原料中C含量的增加,复合材料的力学性能整体呈现先增加后降低的趋势。原料中C最佳添加量为10%(质量分数),对应SiC/B4C复合材料的维氏硬度、抗弯强度和断裂韧性分别为24.4GPa、361.3MPa和4.41MPa·m1/2,复合材料开口气孔率和体积密度分别为0.19%和2.58g/cm3。
The SiC / B4C composites with higher relative density were prepared by reactive sintering SiC, and the influence of C content in raw materials on the phase, microstructure, bulk density and mechanical properties of SiC / B4C composites was investigated. The results show that the phase composition of SiC / B4C composites is B4C, SiC, Si, B13C2 and B12.97Si0.03C2. The microstructure of SiC / B4C composites is that the SiC phase and the B4C phase are uniformly distributed, the free Si is filled in the gaps of the B4C phase and the SiC phase, and the continuous phase is formed. With the increase of C content in the raw materials, the mechanical properties of the composites first increased and then decreased. The optimal addition amount of C in raw material is 10% (mass fraction), corresponding to Vickers hardness, flexural strength and fracture toughness of 24.4GPa, 361.3MPa and 4.41MPa · m1 / 2 for SiC / B4C composites, respectively The porosity and bulk density were 0.19% and 2.58 g / cm3, respectively.