碳纤维增强镁基复合材料的制备及微观结构分析

Preparation and Microstructure of Carbon Fibre Reinforced Mg-based Composite

采用溶胶-凝胶方法,经过水解、浸渍及干燥烧结,在纤维表面涂覆上一层均匀光亮、无裂纹且厚度适中的二氧化硅涂层。在惰性气体保护下实现三维编织碳纤维增强镁基复合材料的压力浸渗制备。通过SEM和XRD等分析碳纤维表面二氧化硅涂层的形貌、成分及其结构以及复合材料中碳纤维与镁基体界面的微观结构。结果表明,二氧化硅涂层厚度适当的碳纤维与镁合金基体之间通过轻微的界面反应,改善了二者间的润湿性,有效促进了镁合金熔液在三维编织碳纤维中的浸渗过程。

The homogeneous and crack-free SiO2 coating with suitable thickness on the surface of carbon fibre is prepared by sol-gel method with procedure of hydrolysis,dipping,gelling,drying and sintering.The 3-dimensional braided carbon fibre reinforced Mg-based composites are prepared in a route of pressure infiltration process under the protection of argon gas.The morphology,structure and composition of the SiO2 coating as well as the interface microstructure between the carbon fibre and the Mg matrix are analyzed by scanning electron microscopy and X-ray diffraction.The results show that during infiltration there is slight reaction between the SiO2 coating and the Mg matrix.And the wetting between the carbon fibre and the Mg matrix is effectively improved and the performance of the impregnation of Mg into the braided carbon fibre is promoted by the reaction.