Hot-Corrosion Behavior of Graded Thermal Barrier Coatings Formed by Plasma-Spraying Process

Investigation of reactions between vanadium oxide and plasma-sprayed yttria-stabilized zirconia coatings

“…The reaction mechanism, however, remains unclear. [14][15][16][17][18] Further complicating the analysis is that Na 2 SO 4 is often combined with V 2 O 5 to produce the corrosive species, and this combination is less reactive with the coating. [13][14][15][16] Published accounts of reactions above ∼750 • C describe yttria, which is basic with respect to the acidic V 2 O 5 , being sequestered or leached from the t -ZrO 2 by the corrosive agent to form YVO 4 .…”

Cyclic Hot Corrosion Failure Behaviors of EB-PVD TBC Systems in the Presence of Sulfate and Vanadate Molten Salts

“…The process of hot corrosion has been emphasized in several earlier studies [1,6,11,14,15]. The hot corrosion action can be expressed by the following reactions [1,6,14,18,19].…”

“…The process of hot corrosion has been emphasized in several earlier studies [1,6,11,14,15]. The hot corrosion action can be expressed by the following reactions [1,6,14,18,19]. After hot corrosion tests, a uniform and dense coating structure provided by EB-PVD technique retards the formation of hot corrosion products [1,5,8,12].…”

“…This may be related to the presence of V2O5 in our hot corrosion salts. Liu et al [30] observed a volumetric increase in thermal barrier coating samples comprising of Sc2O3-Y2O3-ZrO2 (ScYSZ) subjected to hot corrosion test at 1000 °C in a Na2SO4 + V2O5 environment, which was attributed to the phase transformation of zirconium dioxide, from tetragonal to monoclinic phase [1,7,11,16,19,21]. This phase transformation caused crack formation in the coating.…”

Design of novel thermal barrier coatings with reduced thermal conduction and thermal radiation

“…The hot corrosion behavior of TBCs has been studied by Mifune et al [57]. Two types of oxide ceramics C2S -I5 CZ (2CaO.SiC>2 -15wt% CaO.ZrC^) and 8YSZ were investigated in hot corrosion testing environments with V2O5-Na2SOs corrosive ash for 3 hours at 1000°C.…”