1. Chromia layer growth on a Ni-based superalloy: Sub-parabolic kinetics and the role of titanium
- Author
-
Sam Cruchley, Svjetlana Stekovic, M.P. Taylor, Mark Hardy, and Hugh Evans
- Subjects
Materials science ,Chemistry(all) ,General Chemical Engineering ,Kinetics ,Alloy ,A. Superalloys ,chemistry.chemical_element ,engineering.material ,Selective Oxidation ,Materials Science(all) ,Teknik och teknologier ,Oxidation ,General Materials Science ,C. Selective Oxidation ,Superalloys ,Metallurgy ,C. Oxidation ,General Chemistry ,Atmospheric temperature range ,Chromia ,Superalloy ,chemistry ,Rutile ,Chemical Engineering(all) ,engineering ,Engineering and Technology ,Layer (electronics) ,Titanium - Abstract
Oxidation of the Ni-based superalloy RR1000 has been undertaken in air over the temperature range 600-900 degrees C for times up to 5000 h. The surface oxide consisted of a protective Ti-doped chromia layer but with rutile forming on its outer surface. Sub-surface oxidation of Al and Ti also occurred. The thickening kinetics of the chromia layer were sub-parabolic with initial rates around two orders of magnitude higher than expected for Ti-free chromia. This enhancement and the sub-parabolic kinetics are accounted for by Ti-doping of the chromia layer. Over time the enhancement reduced because of Ti-depletion in the alloy. Funding Agencies|Engineering and Physical Sciences Research Council||Rolls-Royce plc
- Published
- 2013