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研究了烧结助剂ＡＩＮ 和Ｂ对Ｃｆ／ＳｉＣ复合材料力学性能的影响。结果表明：Ｂ含量较低时（小于０．５ｗ ｔ％ ），Ｂ的增加能有效地提高复合材料的抗弯强度与断裂韧性，继续增加Ｂ的用量至１ｗ ｔ％ ，虽能大幅度提高复合材料的强度，但使复合材料的断裂韧性大大降低。ＡＩＮ 与ＳｉＣ高温反应形成固溶体，能起到强化和细化基体ＳｉＣ晶粒以及改善ＳｉＣ晶界结构的作用，但对复合材料内纤维与基体间界面的结合影响较小，因此与Ｂ的作用相比，ＡＩＮ 对复合材料密度和力学性能的影响较小。烧结助剂为５ｗ ｔ％ ＡＩＮ－０．５ｗ ｔ％ Ｂ，经１８５０℃和２５ＭＰａ 热压烧结后的Ｃｆ／ＳｉＣ复合材料具有较佳的综合力学性能，其抗弯强度与断裂韧性值分别为５２６．６ＭＰａ 和１７．１４ＭＰａ·ｍ １／２。
The effects of sintering aids AIN and B on the mechanical properties of Cf / SiC composites were investigated. The results show that when the content of B is low (less than 0.5w t%), the increase of B can effectively improve the flexural strength and fracture toughness of the composites and continue to increase the amount of B to 1w t% The strength of the material, but the fracture toughness of the composite material greatly reduced. AIN reacts with SiC at high temperature to form a solid solution, which can enhance and refine matrix SiC grains and improve the grain boundary structure of SiC. However, it has little effect on the bonding between the fibers and the matrix in the composite material. Therefore, AIN has less effect on the density and mechanical properties of composites. Sintering aids for the 5w t% AIN-0.5w t% B, after 1850 ℃ and 25MPa hot-pressed Cf / SiC composites have better mechanical properties, the flexural strength and fracture toughness values were 526 .6 MPa and 17.14 MPa · m 1/2.