A debonding layer is formed on fibers such as silicon carbide fibers by forming a thin film of a metal such as nickel or iron on the silicon carbide fibers and then annealing at a temperature of about 350-550.degree. C. to form a debond layer of a metal silicide and carbon. These fibers having the debond coating can be added to composite forming materials and the mixture treated to form a consolidated composite. A one heating-step method to form a consolidated composite involves inserting the silicon carbide fibers with just the initial metal film coating into the composite forming materials and then heating the mixture to form the debond coating in situ on the fibers and to form the consolidated composite. Preferred heating techniques include high temperature annealing, hot-pressing, or hot isostatic pressing (HIP).
