Csf/BAS玻璃陶瓷复合材料的制备及其力学性能研究

为了提高钡长石(BAS)玻璃陶瓷的力学性能,采用轧膜成型、热压烧结方法制备出纤维分布均匀的致密短碳纤维增强BAS玻璃陶瓷基复合材料(Csf/BAS).采用X射线衍射分析,扫描电子显微镜、透射电子显微镜观察及三点弯曲法与单边开口梁法研究了纤维含量对复合材料组织及力学性能的影响.研究表明:Csf对BAS玻璃陶瓷有良好的强韧化效应.体积分数为30%Csf/BAS复合材料的室温抗弯强度及断裂韧性分别为255 MPa和3.45 MPa.m1/2,其主要的韧化机制为裂纹偏转、纤维的拔出与桥接.用摩尔分数25%Sr代替Ba实现了基体的六方→单斜相的完全转变,进一步提高了复合材料的力学性能.

Preparation and mechanical properties of Csf/BAS glass ceramic matrix composites

In order to obtain higher mechanical properties,dense homogeneous Csf/BAS glass ceramic matrix composites were fabricated by hot pressing.The effects of Csf content on the microstructure and mechanical properties were investigated by means of scanning electron microscope,transmission electron microscope,three-point bending and single-edge notch beam tests.The results show that the mechanical properties of BAS can be effectively increased by incorporation of the short carbon fibers.The flexural strength and the toughness of 30 vol% Csf/BAS are 255 MPa and 3.45 MPa·m1/2,respectively.The main toughening mechanisms are crack deflection,fiber pull-out and bridging.Substituting 25 mol% Sr for Ba in the BAS matrix could promote BAS phase transformation from hexacelsian to celsian,resulting in further improvement of its mechanical properties.