PIP法制备陶瓷基复合材料构件的弯曲性能研究

Studies of Flexural Strength of Ceramic Matrix Composite Component Prepared by PIP Process

采用先驱体转化工艺(PIP)制备三维炭纤维增强碳化硅陶瓷基复合材料(3D-Cf/SiC)构件。通过三点弯曲强度方法分析构件材料的弯曲性能及破坏规律。研究表明:采用三维炭纤维编织的陶瓷基复合材料构件,其复合材料基体的主要成分为β-SiC,材料具有较高的弯曲性能,可达511MPa,构件材料与采用同种PIP工艺制备的3D-Cf/SiC陶瓷基复合材料相比较,强度降低26.4%,这可能是由制备的构件其致密度较低以及后续加工等因素所致。3D-Cf/SiC陶瓷基复合材料在弯曲断裂过程,材料纤维与纤维束被大量拔出,表现出类似金属的较好假塑性断裂特征。

A 3D-Cf/SiC engine component has been made through precursor infiltration pyrolsis (PIP) process. XRD results prove that the SiC matrix is mainly composed of β-SiC. This Cf/SiC component was then cut into small samples with the required size to measure the flexural properties by the three-point test method. These small Cf/SiC samples show their good flexural qualities with a flexural strength of 511 MPa. A decrease of 26.4% in flexural strength occurs in comparison with Cf/SiC composite material prepared using the same PIP process, where the flexural strength is 641 MPa. The difference between Cf/SiC engine component and Cf/SiC composite materials in flexural strength lies in the density of the material and further machining procedure. A lot of pulling-out fibers was found in SEM photographs of fracture surfaces, which shows a characteristic of a rupture.