碳化硅陶瓷复合材料的制备及抗氧化行为  

Preparation and Antioxidant Behavior of Silicon Carbide Ceramic Composites

作　　者：李少峰 LI Shaofeng(Ningbo Donglian Seals Co.,LTD.,Ningbo 315191,Zhejiang,China)

机构地区：[1]宁波东联密封件有限公司,浙江宁波315191

出　　处：《陶瓷学报》2021年第6期1018-1025,共8页Journal of Ceramics

基　　金：宁波市科技创新2025重大专项(2020Z112)。

摘　　要：通过热压烧结工艺制备了碳化硅陶瓷复合材料。对其力学性能进行评估,利用扫描电镜图片(SEM)观察了基体的断口形貌,并利用X射线衍射仪(XRD)对物相进行了分析,讨论了其氧化过程及机理。结果显示:力学性能随TiC添投量的增加而逐步提高,当投入量9 wt.%时为最强,断裂韧性为5.07 MPa·m^(1/2),抗弯强度达到552 MPa,相对密度高达99.3%。分析其增韧机理主要是由于SiC基体中TiC颗粒的离散效果所激发的裂纹偏转和钉扎效用。在空气中经过温度1200℃以及保温2 h的静态氧化条件下,试样表面形成了一层对基体具有有效保护作用的致密性氧化层。Silicon carbide ceramic composites were prepared by using hot pressing sintering.Phase composition and microstructure of the ceramics were characterized by using X-ray diffractometer(XRD)and scanning electron microscopy(SEM)respectively.Mechanical properties and oxidation mechanism of the sintered bodies were studied.The mechanical strength was enhanced gradually with increasing content of TiC.Optimal mechanical properties were achieved in the composite with 9 wt.%,with a fracture toughness of 5.07 MPa·m^(1/2),a bending strength of 552 MPa and relative density of 99.3%.The toughening mechanism is mainly crack deflection and pinning effect,because the TiC particles are dispersed in the SiC matrix.A relatively compact protective oxide-layer was formed on surface of the ceramics,which protected the matrix under the condition of static oxidation in air at 1200℃ for 2 h.

关 键 词：碳化硅 碳化钛 复合材料 热压烧结 抗氧化行为 

分 类 号：TQ174.75[化学工程—陶瓷工业]