Iridium Coating: Processes, Properties and Application. Part I
[61, (1), 16 ]
The successful use in rocket engines of iridium as a barrier coating is an important area of high-temperature application. The Ir coating must be continuous and dense in order to protect the underlying material from corrosion and oxidation. The microstructure and morphology of the coating can be effectively controlled by varying the deposition conditions. The microstructure has an important influence on the physical and mechanical properties of the coating. A number of deposition processes, which have different conditions and requirements, have been employed to produce Ir coatings on various substrate materials. Part I of this paper presents the introduction and reviews the different deposition processes, while Part II will deal with texture and structure evolution, mechanical properties, growth mechanisms and applications of Ir coatings. The mechanisms of micropore formation after high-temperature treatment will also be investigated in some detail.