Damage Mechanisms in Ti₃Al Matrix Composites

The paper discusses experimental observations and some related theoretical results associated with the mechanical response of two Ti₃Al matrix composites, subjected to transverse loading. Both composites contain continuous unidirectional fibers; however, there are considerable differences in the composition of the two interfaces. The Ti₃Al/SCS-6 system contains brittle reaction products around the fibers that degrade the strength of the composite. The second composite consists of a Ti₃Al matrix reinforced by sapphire fibers that are strongly bonded to the matrix. Experimental observations indicate that the damage mechanisms in the two composites are substantially different. Utilizing elastic analyses of the local stress field, an attempt was made to explain the dependence of the observed damage mechanisms on the residual field and the properties of the interface.