The microstructural studies of suspension plasma sprayed zirconia coatings with the use of high-energy plasma torchesShow others and affiliations
2017 (English)In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 318, p. 250-261Article in journal (Refereed) Published
Abstract [en]
The presented studies are focused on the microstructure characterization of zirconia-based coatings deposited by two types of high-energy plasma torches: (i) Axial III; and, (ii) hybrid version of Water-Stabilized Plasma (WSP) torch. The suspensions were formulated using solid dispersed phase of: (i) zirconia stabilized with 14 wt of Y2O3 and (ii) zirconia stabilized with 24 wt% of CeO2 + 2.5 wt% of Y2O3 and continuous phase of water with ethanol. The spray process parameters were optimized for each plasma set-up individually. The in-flight observations (shadowgraphy) were performed to optimize the injection of the liquid feedstock into the plasma jet. Then the coating’s morphology and coating/substrate interface were characterized using conventional light microscopy and scanning electron microscopy (SEM). The results showed that through the change of deposition parameters various coatings microstructures could be obtained, in particular columnar and two-zones structures. The EDS/EDX and XRD studies showed that there was no significant change in chemical/phase composition of zirconia material before and after spraying. Electron backscatter diffraction (EBSD) method allowed to analyze the grain size in the coating microstructure as well as crystallographic orientation of individual grains. The results showed that coatings were characterized by submicrometric microstructure what corresponded to the size of powder particles used to formulate suspension. No texture was observed in the coatings microstructure. The surface topography analysis which was performed by confocal scanning laser microscopy (CSLM) and Shape From Shading (SFS) technique proved the great influence of suspension concentration on the coating structure. (C) 2017 Elsevier B.V. All rights reserved.
Place, publisher, year, edition, pages
2017. Vol. 318, p. 250-261
Keywords [en]
Water-stabilized plasma (WSP); Gas-stabilized plasma (GSP); Suspension injection; Columnar microstructure; Two-zones microstructure; Electron backscatter diffraction
National Category
Manufacturing, Surface and Joining Technology
Research subject
ENGINEERING, Manufacturing and materials engineering
Identifiers
URN: urn:nbn:se:hv:diva-11037DOI: 10.1016/j.surfcoat.2017.03.025ISI: 000402356100029Scopus ID: 2-s2.0-85016063934OAI: oai:DiVA.org:hv-11037DiVA, id: diva2:1113892
Conference
7th International Meeting on Thermal Spraying (RIPT), Lumoges, FRANCE, DEC 09-11, 2015
Note
Funders: National Science Centre (Poland) grant Sonata, UMO-2013/11/D/ST8/03400, GA15-12145S
2017-06-222017-06-222020-02-06Bibliographically approved