High-temperature corrosion behavior of BaCeO3 in Na2SO4+V2O5 salt mixture

This study examines the high temperature corrosion response and thermal barrier characteristics of BaCeO 3 . The phase stability and decomposition behaviour of BaCeO 3 were studied using TG-DSC analysis. The thermal diffusivity and thermal expansion coefficient were determined using Laser Flash Analysis and Dilatometry techniques. Microhardness of the sintered BaCeO 3 was measured using Vickers micro indentation technique whereas the elastic modulus was found using Ultrasonic technique. Corrosion tests were performed on both BaCeO 3 coatings and pellet samples in 32 wt% Na 2 SO 4 + 68 wt% V 2 O 5 salt melt at 900ºC, and the corrosion process was analyzed using XRD and SEM-EDS. The main corrosion product found in the samples exposed to 32 wt% Na 2 SO 4 + 68 wt% V 2 O 5 mixture was Ba 3 V 2 O 8 , with small amounts of CeO 2 and BaSO 4 . SEM-EDS examination of the corroded samples highlighted the significant corrosive action on BaCeO 3 , indicating the acidic leaching of Ba 2+ ions, which then reacted with the salt mixture. The formation of NaVO 3 intensified atomic mobility, aggravating the corrosion process. Comparing the hot corrosion of BaCeO 3 in pure Na 2 SO 4 and V 2 O 5 melts with that in the 32 wt% Na 2 SO 4 + 68 wt% V 2 O 5 mixture confirmed this effect. No discernible peaks corresponding to any Ce-V-O compound were observed in any of the corrosion patterns, suggesting a preference for BaO over CeO 2 in the corrosion process due to its stronger basic nature.