FCVI工艺制备SiC_f/SiC复合材料结构与性能研究

A Study on Microstructure and Properties of SiC_f/SiC Composite Fabricated by FCVI

采用热梯度强制流动化学气相渗积 (FCVI)工艺制备 Si Cf/Si C复合材料 ,测试了复合材料的性能。制备的复合材料密度达到 2 .3g/cm3,强度为 2 91MPa,断裂韧性为 11.4MPa·m1 / 2 。运用 SEM,TEM,X射线衍射等分析手段对复合材料的微观结构进行了表征。结果表明 :渗积的基体材料为 β- Si C,晶粒尺寸为亚微米级 ,结晶度良好。通过对断口形貌的观察 ,分析了增韧机制。

SiC f/SiC composite was fabricated by forced flow thermal gradient chemical vapor infiltration (FCVI) The density of composite is 2 3g/cm 3.The flexural strength and fracture toughness of SiC f/SiC compsites were tested: the flexural strength is 291 MPa, the fracture toughness is 11 4 MPa·m 1/2 The microscopy structure was characterized by SEM, TEM and X ray diffraction The results show that SiC matrix fabricated by FCVI is β SiC, which has sub micron grain size and good crystallinity And the toughening mechanism was also investigated by morphology of the fractrue surface