Improvement of mechanical properties of SiC(SCS-6) fibre-reinforced Ti3AlC2 matrix composites with Ti barrier layer

In this study, silicon carbide fibre-reinforced Ti3AlC2 matrix composites with a Ti barrier layer were prepared by hot-pressing at 1250 °C and 1300 °C. The microstructure of the composites was characterised by field-emission scanning electron microscopy. During consolidation, reactions of Ti with the fibres and the matrix led to the formation of an interfacial reaction zone between the fibres and the matrix and a matrix reaction zone within the matrix. Quantitative elemental distribution maps of both reaction zones were collected using energy-dispersive spectroscopy. The results revealed that the Ti layer effectively hindered the inward diffusion of Al from the matrix. In addition, the flexural strength of the composite was significantly improved with the addition of the Ti layer. Furthermore, noncatastrophic fracture behaviour was observed for the composites. The improvement of their mechanical behaviour is attributed to the added Ti layer, which prevented strength degradation of the fibres via a severe interface reaction.