Advanced Microscopic Study of Suspension Plasma-Sprayed Zirconia Coatings with Different Microstructures

Paweł Sokołowski (1, 2) , Lech Pawłowski (1) , Dagmar Dietrich (3) , Thomas Lampke (3) , David Jech (4)

1 SPCTS-AXE2 - Axe 2 : procédés plasmas et lasers
2 Wroclaw University of Science and Technology
3 Chemnitz University of Technology / Technische Universität Chemnitz
4 BUT - Brno University of Technology [Brno]

The present paper is focused on the characterization of the differences between two microstructures that can be obtained using SPS technology, namely (i) columnar and (ii) two-zone microstructure including lamellas and fine unmelted particulates. The optimization of spray parameters was made, and the advanced microstructural studies of obtained coatings were performed. The work was focused on zirconia stabilized by yttria (YSZ, ZrO2 + 14 wt.% Y2O3) and both by yttria and ceria (YCSZ, ZrO2 + 24 wt.% CeO2 + 2.5 wt.% Y2O3) which are frequently used as thermal barrier coatings. Two types of microstructure were achieved using two different plasma torches, namely SG-100 of Praxair and Triplex of Oerlikon Metco. The microstructure of prepared coatings was analyzed using scanning electron microscopy with secondary electrons detector and backscattered electrons. Energy dispersive spectroscopy was performed to analyze the chemical composition of sprayed coatings. By electron backscatter diffraction grain shape, size, and crystal orientation were determined. The analysis enabled the discussion of the coatings growth mechanism. Finally, the Shape From Shading technique was applied to recreate and to analyze 3D views of coatings’ topographies, and using laser confocal microscopy, the surface roughness was examined.

Mots clés: yttria-ceria-stabilized zirconia; two-zone microstructure; thermal barrier coatings; suspension plasma spraying; yttria-stabilized zirconia; electron backscatter diffraction; columnar microstructure; diffraction

Domaines: Matériaux; Matériaux; Plasmas

Paweł Sokołowski, Lech Pawłowski, Dagmar Dietrich, Thomas Lampke, David Jech. Advanced Microscopic Study of Suspension Plasma-Sprayed Zirconia Coatings with Different Microstructures. Journal of Thermal Spray Technology, 2016, 25 (1-2), pp.94 - 104. ⟨10.1007/s11666-015-0310-7⟩. ⟨hal-01875694⟩