Abstract: Four kinds of Mg alloys reinforced with carbon fibres were fabricated by a gas pressure infiltration technique. The fibres were pre-coated a SiO2 layer prior to fabrication. Different microstructures and interactions in the fibre-matrix interface of these composites were observed by transmission electron microscopy (TEM). The results showed that the interfacial interaction strongly depended on the content of Al in the Mg-based matrices. The microstructure of the interface could then be controlled by adjusting the Al content of the Mg-based matrix. In addition, fibres extracted from different Mg-based matrix all had some degradation owing to the interfacial reaction and the fibre-matrix interdiffusion.

Key words: Carbon fibre, SiO2 coating, Microstructure, Interface