Deposition Mechanisms of Thick Lanthanum Zirconate Coatings by Spray Pyrolysis
Abstract:An aqueous nitrate‐based precursor solution was deposited on stainless steel substrate by spray pyrolysis to produce thick lanthanum zirconate coatings for thermal barrier coating application. The as‐deposited, dried, and further annealed coatings were characterized by thermogravimetry, Fourier transform infrared spectroscopy, X‐ray diffraction, and scanning electron microscopy. The influence of the substrate temperature on the film formation and microstructure has been carefully studied for a better understanding of the deposition mechanisms. A temperature range corresponding to the deposition of an ionic salt liquid was found to be critical to obtain thick crack‐free green coatings. Further heat treatment was necessary to decompose the nitrate species into an oxide coating with a fine porous microstructure.
Document Type: Research Article
Publication date: December 1, 2011