kinetic COnsiderations for processing a Diffusion NiAl Coating Uniforaly Doped with A Reactive Element By Chemical Vapor Deposition

摘要

Recent manufacturing advances in aluminzing by chemical vapor deposition offer new processing opportunities to further improve the performance of diffusion NiAl and Al bond coatings used for thermal barier coating applications. In particulr, the dynamic versatility of the CVD aluminizing process provides an avenue of uniformly doping the coating matrix with a rective element such as Hf via proactive contro lof the gas phase ocncentration ofits precuresor. However, with the apparent lack of meaningful experimental data, considerable uncertainties exist to properly project the viability of the doping approach for eventual industrial practice. This paper describes some of the critical research issurs associated with the doping concept, with emphasis on generating experimental data that will help understand the kinetics of the doping process and will be useful for model-based porcess optimization.