Investigation of three steps of hot corrosion process in Y2O3 stabilized ZrO2 coatings including nano zones

High-temperature corrosion behavior of zirconia ceramic in molten Na2SO4+NaVO3 salt mixture

“…The volume fraction of monoclinic zirconia formed during the hot corrosion test gradually increased to 72.08% as the hot corrosion dwelling time increased to 96 h. Detailed results will be seen in another paper. Our results are in agreement with the Daroonparvar [32] and Jamali's [31] conclusions. Fig.…”

“…Nejati et al [36] also confirmed that Na 2 SO 4 had no chemical effect on CSZ coating at the elevated temperature of 1050 1C. However, Na 2 SO 4 has been known as an accelerator factor of chemical reactions during hot corrosion [32]. Furthermore, the molten NaVO 3 is also reported to increase mobility of Y 3 þ , hence further promotes the depletion of yttria from 8YSZ and the growth of YVO 4 crystals [37].…”

“…Daroonparvar evaluated the hot corrosion behavior of nanostructured and conventional Y 2 O 3 stabilized ZrO 2 coatings in fused V 2 O 5 -Na 2 SO 4 salts. After hot corrosion test, the volume fraction of monoclinic zirconia was calculated to be 60% and 40% for conventional and nanostructured YSZ coatings, respectively [32]. In another experiment, the hot corrosion studies for micron sized 8YSZ ceramic were carried out.…”

Microstructural characterisation of air plasma sprayed nanostructure ceramic coatings on Mg–1%Ca alloys (bonded by NiCoCrAlYTa alloy)

“…Fig. 5b, d and e shows magnified images of the fractured nano-Al 2 O 3 -13%TiO 2 coating, which consists of both fully melted regions and partially melted regions, which are consistent with the bimodal microstructure that has been reported in many scientific papers [29,32,37]. It is easily seen that the structure of the fully melted regions (see Fig.…”

“…Thus, they are not able to cross the streamline in the spray jet and would be segregated to its periphery without depositing on the substrate. In order to overcome this problem, reconstitution of the nanoparticles into micrometre-sized granules is essential [23,37]. Therefore, in this study, agglomerated nanostructure Al 2 O 3 -13%TiO 2 powders (Nanox S2613S, Inframat Corporation, USA), (with size in the range of 10-50 mm)) (see Fig.…”