OFF-AXIS LOADING OF SILICON-CARBIDE FIBERS IN A TITANIUM ALUMINIDE MATRIX

Silicon carbide SCS-6 fibers in a Ti24Al + 11Nb matrix were subjected to off axis loading in a ''thin-slice'' pushout test, resulting in various combinations of shear, radial compression, and tension along the fibers as a function of orientation angle. The load necessary for debonding decreased as the orientation angle increased, whereas the average frictional sliding stress after 60 s of sliding remained relatively constant for orientation angles less than 30 deg. Analyses of the specimen bending stresses and of the contact stresses by finite element modelling and thin plate theory are presented.