Abstract

Method and protective coating composition for preventing or minimizing costion or melting of titanium and combustible alloys thereof. Two layers of coatings are applied, the first layer preventing diffusion of the second layer into the titanium or alloy even at elevated temperatures, and the second layer suppressing titanium combustion. The first layer contains chromium, molybdenum, niobium, tantalum, vanadium, zirconium, platinum, or rhodium or a combination thereof or alloy of any of these metals. The second layer contains copper, aluminum, gold, nickel, silver, cobalt or a combination thereof or alloy of any of these metals. By preventing diffusion of the second layer into the substrate, the first layer prevents degradation of substrate engineering or mechanical properties. When in an operating aircraft engine molten or burning titanium or other material arrives at the surface of the second layer, the second layer melts directly underneath the molten material which then is moved downstream by the engine airflow, leaving behind a non-melted substrate.