Cf/SiC制备过程中纤维热应力损伤研究

采用束丝碳纤维和聚碳硅烷先驱体浸渍裂解工艺制成C_f/SiC丝束,并进行了分析表征,研究了其中的纤维受损情况。实验结果表明,由于先驱体聚碳硅烷在浸渍裂解时倾向于以纤维为依托进行热解,并且其中较多量的氧及杂质的存在将对纤维造成损伤,因而会形成较强的纤维基体界面;纤维基体热膨胀系数失配等因素造成的热应力将使纤维进一步受损。 

THERMAL STRESS DAMAGE OF FIBER IN THE PREPARATION OF Cf/SiC

In this paper, C f/SiC was prepared by the process of precursor infiltration pyrolysis(PIP) using carbon fiber bundles and polycarbosilane(PCS), and the damage extent of fibers in C f/SiC was studied. The results show that strongly bonded fiber/matrix interface will come into being because PCS is ready to pyrolyze surrounding the fibers, and the considerable oxygen and impurity hurts the fiber. At the same time, the thermal stress hurts the fiber greatly, which is caused by the imparity of the fiber matrix coefficients of thermal expansion and considerable bulk shrink in the process of pyrolysis.