Transverse fracture study of a ceramic composite by double torsion technique under oxidizing conditions

This paper makes a critique of the double torsion (DT) test technique in studying the transverse fracture behavior of SiC/CAS-II glass-ceramic composite. Previous to this study, there has not been much work on high temperature transverse properties of this composite. The applicability of the DT method to elevated temperatures was demonstrated. Test rate had a considerable effect on the compliance for the DT tests performed at high temperatures. This is believed to be due to the thermal expansion/shrinkage of the metals used in the DT test system. However, this did not appear to be a problem for the purposes of this study. Transverse fracture toughness data, coupled with scanning electron microscopy and microdebonding analysis of the fracture surfaces, indicated no significant effect of high temperature oxidative environment on cracking parallel to the fibers in SiC/CAS-II composite.