Texture and microstructure of ZrO2-4mol% Y2O3 layers obliquely deposited by EB-PVD

• Published in: Surface & coatings technology 2006-01, Vol.200 (8), p.2725-2730
• Main Authors: Wada, Kunihiko, Yoshiya, Masato, Yamaguchi, Norio, Matsubara, Hideaki
• Format: Article
• Language: English
• Subjects: Applied sciences; Cross-disciplinary physics: materials science; rheology; Electron beam evaporation; Exact sciences and technology; Materials science; Metals. Metallurgy; Monte Carlo simulation; Nonmetallic coatings; Other topics in materials science; Physics; Production techniques; Scanning electron microscopy (SEM); Surface treatment; Thermal barrier coatings; X-ray diffraction; Zirconium oxide
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2005.02.121

Observing texture and microstructure growth in coating layers during oblique deposition provides the most fundamental information to optimize the process parameters of the deposition process. In this study, the columnar structure of 4 mol% Y2O3 partially stabilized ZrO2 (YSZ) coating layers produced by electron beam physical vapor deposition (EB-PVD) process was experimentally investigated. Most results could be summarized as a function of vapor incident angle (VIA), α. While a mixture of and textured columns was observed in the samples deposited at a low α less than 30°, single textured columns were observed at a high α (>30°). Therefore, the was the preferential crystallographic growth direction under oblique deposition. However, the direction of did not accord with the geometric growth direction of the columns, which is approximately predicted based on so-called the tangent rule. It is likely that the mismatch between these directions results in the formation of feather-like structure, which has been commonly reported. In addition to crystallographic observation, the porosities in the coating layers were investigated. The tendency of the porosity with the change of VIA qualitatively agreed with the previously reported prediction based on the Monte Carlo simulation method.