Spouted bed metallorganic chemical vapor deposition of ruthenium on NiCoCrAIYTa powders

This paper reports on the spouted bed metallorganic chemical vapor deposition (SBMOCVD) of ruthenium on NiCoCrAIYTa commercial powders. The aim is to propose an economic, versatile and time saving process for the screening of the doping by platinum group elements of thermal barrier coatings applied on gas turbine engine blades, in order to improve their oxidation and corrosion resistance. Information on the spouting of the NiCoCrAIYTa powders and on the SBMOCVD reactor is provided in the first part of the paper. Following, two deposition routes for the CVD of ruthenium starting form ruthenocene are described. The first implies high temperature reaction with hydrogen and yields crystalline Ru nanoparticles on the surface of the powders. The second is a low temperature reaction with oxygen. It yields ruthenium oxide which in turn is reduced in situ to yield amorphous Ru. Both processes lead to uniform doping of the powders.