N. Hitchman, A. Feuerstein, J. Knapp, L. Li, D. Lemen, T. A. Taylor, Praxair Surface Technologies, Inc., Indianapolis, IN
State of the art advanced thermal barrier coating (TBC) systems for aircraft engine and power generation hot section components consist of EBPVD applied yttria stabilized zirconia and platinum modified diffusion aluminide bond coating. Thermally-sprayed ceramic coatings are still extensively used for combustors and power generation blades and vanes. This paper highlights the key features of plasma spray and EBPVD coating processes for TBC. The process and coating characteristics of APS low density and dense vertically cracked (DVC) Zircoat™ TBC as well as EBPVD coatings are described. New trends in TBC development such as low conductivity compositions and ultra pure Zirconia for improved sintering resistance are addressed. The major coating cost elements such as material, equipment and processing are explained for the different technologies.
