Characterization of flame sprayed abradable seal NiCrAl-bentonite coatings

0508578 - ÚFP 2020 RIV CZ eng C - Conference Paper (international conference)
Houdková, Š. - Česánek, Z. - Schubert, J. - Lukáč, František - Bystrianský, M.
Characterization of flame sprayed abradable seal NiCrAl-bentonite coatings.
27th International Conference on Metallurgy and Materials. Ostrava: Tanger, 2018, s. 979-984. ISBN 978-80-87294-84-0.
[27th International Conference on Metallurgy and Materials. Brno (CZ), 23.05.2018-25.05.2018]
Institutional support: RVO:61389021
Keywords : Abradability * Abradable seal * Flame spray * NiCrAl-Bentonite
OECD category: Materials engineering

The NiCrAl-21% Bentonite abradable coating, deposited by flame spraying, was exposed to 720°C / 1 hour air-annealing to evaluate its resistance against heat-induced changes. The SEM and XRD microstructure evaluation was done. After the air-annealing, the increase of HR15Y surface hardness was recorded and accompanied with decrease of abradability evaluated by Progressive Readability Hardness (PAH) test, although no demonstrable microstructural changes was recorded by SEM. XRD analyses evidenced the formation of nickel oxides and ordered Ni3Al phase during the air-annealing. Besides the abradable coating evaluation, this work brings the verification of the potential of PAH for scratch hardness testing. The measurement provides the results with low scatter, compared to usual surface hardness testing, and enables to distinguish between the depth of indentation in loaded and unloaded state, pointing out to the elastic/plastic deformation ratio.
Permanent Link: http://hdl.handle.net/11104/0299447