Electron Beam/Physical Vapor Deposition (EB/PVD) Coating Process Mapping for Complex Shapes

ABSTRACT: Thermal barrier coatings are currently employed to thermally protect gas turbine engine components from high gas inlet temperatures to improve the performance (fuel efficiency and thrust) of these engines. Enhanced benefits are envisioned in future TBC systems if TBC"s reliability and durability can be improved. One approach to achieve more reliable TBCs is the development of non destructive methodologies to determine processing / structure / property relationships for electron beam-physical vapor deposited (EB-PVD) thermal barrier coatings (TBC) in both an ex-situ and in-situ manner. This would enable the creation of comprehensive process maps that could be used along with real time feedback during manufacturing to greatly enhance the capabilities of an EB-PVD system to reliably produce high quality TBC coatings. To achieve this, Directed Vapor Technologies International (DVTI) and Reliacoat Technologies (RCT) will investigate the use of a curvature measurement technique to non-destructively determine critical, design related mechanical properties of EB-PVD deposited coatings and link these properties to processing parameters and coating performance. In Phase I, the apparatus and relevant analysis had been successfully demonstrated. In Phase II, the applicability of this approach will be demonstrated for in-situ testing to establish advanced process maps for EB-PVD based TBC processing techniques. BENEFIT: This research is anticipated to establish advanced process maps for EB-PVD based TBC processing techniques utilizing novel non-destructive ex-situ and in-situ curvature measurement approaches. The research will enable tighter lifetime distributions and aid the development of advanced TBC coating systems which will result in more reliable and durable TBC coatings. These developments significantly increase the potential for TBC coatings to become prime reliant which would result in much greater gas turbine engine performance. This would help enable the realization of advanced gas turbine engine designs while leading to several percent thrust improvement or specific fuel consumption reduction for current turbine engines. These advances will not only benefit military engines, but also commercial and industrial gas turbines. In addition, the innovative approach proposed here will reduce the time and expense for refurbishing and repairing blades during engine overhauls, thus improving military readiness and reducing the cost of maintaining commercial aircraft. The demonstration of such novel concepts may also be applied to other functional coatings, such as environmental barrier coatings and damping coatings where reliability is also critical.