SiC微粉含量对先驱体转化制备碳纤维布增强碳化硅复合材料性能的影响

Effect of SiC Powder Content on the Mechanical Properties of Carbon Fiber Cloth Reinforced SiC Composites Fabricated via Precursor Pyrolysis

以聚碳硅烷(PCS)、二乙烯基苯(DVB)和SiC微粉为原料制备了碳纤维布增强碳化硅复合材料,考察了SiC微粉含量对材料结构与性能的影响。实验表明,SiC微粉含量过低,材料内部存在大的孔洞,容易造成应力集中,导致材料的力学性能较差;而当SiC微粉含量较高时,在制备过程中微粉对碳纤维机械损伤加大,同样导致材料力学性能下降。当SiC微粉含量为30%(质量分数)时,所制备的材料的力学性能较好,其弯曲强度和拉伸强度分别为246.4MPa和72.5MPa。

Carbon fiber cloth reinforced silicon carbide(C_f /SiC) composites were fabricated with polycarbosilane(PCS) and divinylbenzene (DVB) as precursors and SiC as inert fillers. The effects of SiC powder(SiC_p) content on the structure and properties of C_f/SiC composites were investigated. The results show that the mechanical properties of the cloth fabricated with lesser SiC_p content were low because big pores existed in the composites which led to stress concentration. But when the content was excessive, SiC_p would hurt the carbon fiber seriously. As a result, the properties of the composites decreased. It was found that when fabricated with 30% SiC_p (mass fraction) the composites exhibited highest properties, and the flexural strength and tensile strength reached 246.4MPa and 72.5MPa, respectively.