Oxidation-resistant coatings for application on high-temperature titanium alloys in aeroengines

High-temperature application of titanium alloys in aeroengines is often limited by their insufficient resistance to the aggressive environment. Magnetron-sputtered Ti-Al based coatings were developed in order to increase the maximum service temperature of conventional titanium alloys from the present 520-600 degrees C, the temperature limit set by the mechanical capabilities of most advances alloys. The coatings not only demonstrated excellent oxidation resistance but also demonstrated beneficial effects on mechanical properties. Most importantly, the fatigue behavior of the substrate alloys was not degraded, a major hurdle for coating application on titanium alloys so far. Initial results on Cr-containing Ti-Al based coatings indicated significant potential for application on titanium aluminides.