Micro-chemical and -morphological features of heat treated plasma sprayed zirconia-based thermal barrier coatings

• Published in: Thin solid films Vol. 549; pp. 321 - 329
• Main Authors: Cortese, Barbara, Caschera, Daniela, de Caro, Tilde, Ingo, Gabriel Maria
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 31.12.2013; Elsevier
• Subjects: Ceria–yttria stabilized zirconia; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Electron and ion emission by liquids and solids; impact phenomena; Exact sciences and technology; Field emission, ionization, evaporation, and desorption; Heat treatment; Ion and electron beam-assisted deposition; ion plating; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Phase composition; Physics; Physics of gases, plasmas and electric discharges; Physics of plasmas and electric discharges; Plasma applications; Plasma-based ion implantation and deposition; Spray coating techniques; Thermal barrier coatings; Yttria stabilized zirconia; Thermal barrier coatings; Heat treatment; Yttria stabilized zirconia; Ceria–yttria stabilized zirconia; Phase composition; Porous materials; Field emission; Chemical composition; Ceria-yttria stabilized zirconia; Temperature dependence; Scanning electron microscopy; Phase transformations; Spray coatings; Secondary ion mass spectrometry; Stabilized zirconia; Dispersive spectrometry; Surface composition; Heat treatments; Valence; Sintering; Morphology; Crystal-phase transformations; Microstructure; Impurity segregation; Plasma deposition; X-ray photoelectron spectra
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2013.04.155

Zirconia-based plasma-sprayed coatings are extensively used in jet and land-based engines as thermal barrier coatings (TBCs) for protecting and insulating gas turbine metal components from the extreme temperature in the hot gas extending the engine life capabilities and service performances as well as reducing fuel consumption. Zirconia-based thermal barrier coatings stabilized with yttria and ceria were prepared by means of atmospheric plasma spray (APS) and thermal treated at different temperatures. The resulting fractured heated surfaces have been studied by means of X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM) combined with energy dispersive spectrometry (EDS) and secondary ion mass spectrometry (SIMS) in order to study the surface micro-chemical composition and morphology. The results disclose the variation of the stabilizing oxide amount, the occurrence of valence state modifications of cerium, impurity segregation phenomena and sintering. High temperature sintering influenced the porous microstructure leading to structural changes of the surface. This information confirmed that chemical and morphological aspects in plasma sprayed TBCs must be known in order to understand and predict relationships between the parameters of plasma spray process and TBC features, properties and performances for a better design of reliable TBCs. •Yttria and Ceria stabilized zirconia-based TBCs were prepared by means of atmospheric plasma spray (APS) and thermal treated at different temperatures.•The chemical and morphological structure of the fractured materials were analysed.•Morphology and structural changes of the coatings depended on the nucleation and temperature treatments.•Ceria stabilized TBCs showed higher phase stability than Yttria’s.