Chemical Vapor Deposition of TBC: An Alternative Process for Gas Turbine Components

Abstract

This paper deals with the development of a new process for the deposition of thermal barrier coatings (TBC) based on chemical vapor deposition (CVD). The research program started in September 1998 under a BRITE/Euram III project. The CVD process involves the evaporation of zirconium and yttrium starting from metal-organic precursors and their reaction with oxygen in a hot wall reactor in order to deposit TBC layers. The influence of different deposition parameters such as evaporation temperature, pressure, and substrate temperature on structure, deposition rate, and process yield are described. The characterization of different precursors behavior is also described. Preliminary results, obtained with optimized conditions, have shown ZrO2-Y2O3 columnar layers with deposition rates of interest from an industrial point of view.