自蔓延高温合成C_f/TiC-TiB_2复合材料的力学性能研究

Study on Mechanical Properties of C_f/TiC-TiB_2 Composites Combustion-Synthesized by SHS

为提高TiC-TiB2复合材料的强度和韧性以拓宽其应用,用自蔓延高温合成结合准热等静压(SHS/PHIP)的方法制备了碳纤维质量分数分别为0%,1%,3%,5%,7%的Cf/TiC-TiB2复合材料。通过实验测定,随碳纤维含量的增加,Cf/TiC-TiB2复合材料的弯曲强度和断裂韧性都呈现先增加后降低的趋势。当碳纤维含量达到3%时,强度和韧性分别为406.12MPa和6.26MPa.m1/2,均高于纯TiC-TiB2陶瓷。纤维的断裂、桥连和裂纹的偏转是复合材料的主要增韧机制。

To improve strength and toughness of TiC-TiB2 composites and widen their applications, Cf/TiC-TiB2 ceramic composites containing 0wt%, 1wt%, 3wt%, 5wt%, 7wt% carbon fiber were fabricated respectively by Self-propagating High temperature Synthesis and Pseudo Heat Isostatic Press （SHS/PHIP）. The results show that the bend strength and toughness of Cf/TiC-TiB2 ceramic composites increased first and then decreased later with increasing of the content of carbon fiber. When the content of carbon fiber was 3wt%, the bend strength and toughness of Cp/TiC-TiB2 ceramic composites reached 406.12 MPa 和 6.26 MPa.min, respectively, which were higher than that of pure TiC-TiB2 composites. The main toughening mechanism was attributed to fracture and bridging of carbon fiber and crack deflexion.