Mechanical behavior of a Nicalon/SiC composite at room temperature and 1000°C

The effects of fabric orientation on the mechanical behavior of a Nicalon/SiC composite were investigated by performing flexure tests at room temperature in air, and at 1000°C in argon environment. The specimen configurations were designated as edge-on and transverse, depending on whether the load was applied parallel or normal to the fabric plies, respectively. The monotonic and fatigue behavior of the material was not noticeably affected by fabric orientation, at both room and elevated temperatures. The interlaminar pores in the material appeared to have acted as stress concentration sites. The cracks initiated from these sites linked up the interlaminar pores, resulting in specimen severance under monotonic and fatigue loadings, in both edge-on and transverse orientations.