Damage in Oxidized Titanium Metal Matrix Composites

Abstract

The oxidation effects on surface crack development of oxidized Ti 15-3 and Ti β-21S Metal Matrix Composite (MMC) unidirectional laminates under applied mechanical loading are investigated in the present study. Experimental results of surface crack development as a function of applied load are presented. An approximate mechanical model is established and a stress analysis of an oxidized laminate with surface cracks is performed. To simplify the analysis, motivated by experimental observations, a periodic distribution of surface cracks in the oxide layer is assumed. The critical value of the applied mechanical load, which is necessary for the formation of new cracks, as a function of crack density and phase transformation induced eigenstrain are studied.