Investigation of interface debonding behaviour in a unidirectional SiC fibre reinforced Ti-17 composite by a single fibre push-out technique

Abstract

The debonding behaviour at the fibre/matrix interface in a unidirectional continuous carbon-coated SiC fibre reinforced Ti-17 composite was investigated. Single fibre push-out testing on thin slice specimen by micro-indentation was employed to evaluate the interface debonding strength. In order to investigate interface debonding modes, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were utilised to observe the microstructure at the fibre/matrix interface region after the fibres were pushed out. It is found that the interface debonding strength is evaluated to be 108.2 MPa in the composite. The interface debonding occurs at the interface between the interface reaction zone (RZ) and the carbon coating on the fibre surface. The carbon coating/SiC fibre interface and the RZ/matrix interface remain intact after the fibre was pushed out.