D.D. Hass, H.N.G. Wadley, P.A. Parrish

Electron Beam Directed Vapor Deposition of Thermal Barrier Coatings

Journal of Vacuum Science and Technology A, In Press, 1998.

Thermal barrier coatings (TBC's) are used for the thermal protection of turbine engine components to increase engine durability and could result in higher operating temperatures and thus substantial improvements in the efficiency of gas turbine engines. here, an emerging electron beam-directed vapor deposition (EB-DVD) approach is explored as a method for producing TBC's. The EB-DVD technique combines low vacuum (10-3 - 10 Torr) electron beam evaporation with a carrier gas jet to rapidly create and efficiently transport evaporant to a deposition surface. Studies of the deposition of yttria partially stabilized zirconia (YSZ) and reactively formed zirconia coatings have been performed and the microstructure, phase content, and texture of deposited layers are reported. Results indicate an ability to form YSZ and zirconia coatings at a rate in excess of 50 mm min-1 which have the columnar microstructure necessary for high performance gas turbine applications.