Evaluation of Internal Cohesion of Plasma-Sprayed Coatings by Cavitation Test: Feasibility Study

0538124 - ÚFP 2021 RIV CZ eng J - Journal Article
Mušálek, Radek - Nardozza, E. - Tesař, Tomáš - Medřický, Jan
Evaluation of Internal Cohesion of Plasma-Sprayed Coatings by Cavitation Test: Feasibility Study.
Acta Polytechnica. Roč. 27, Červen (2020), s. 73-78. ISSN 1210-2709. E-ISSN 1805-2363
R&D Projects: GA ČR(CZ) GA19-10246S
Institutional support: RVO:61389021
Keywords : Cavitation damage * cohesion * failure analysis * plasma spray coatings
OECD category: Materials engineering
Method of publishing: Open access
https://ojs.cvut.cz/ojs/index.php/APP/article/view/6691/5733

Mechanical characterization of plasma-sprayed coatings at microscopic level representsa major challenge due to the presence of numerous inherent microstructural features such as cracks,pores, or splat boundaries, which complicate coatings characterization by conventional testing methods.Need for reliable testing of structural integrity of newly developed multiphase plasma-sprayed coatingsintroduced even more complexity to the testing. In this study, applicability of indirect vibratorycavitation test (adapted from ASTM G32 standard) for such testing was evaluated. Three plasma-sprayed coatings having distinctive microstructures were tested: i) conventional alumina coatingdeposited from coarse powder, ii) hybrid coating deposited by co-spraying of coarse alumina powderand fine yttria-stabilized zirconia (YSZ) suspension, and iii) compact alumina coating deposited fromfine ethanol-based suspension. Differences in the coatings internal cohesion were reflected in differentfailure mechanisms observed within the cavitation crater by scanning electron microscopy and meanerosion rates being i) 280μm/hour, ii) 97μm/hour and iii) 14μm/hour, respectively.
Permanent Link: http://hdl.handle.net/11104/0315943