Columnar and DVC structured thermal barrier coatings deposited by suspension plasma spray: high temperature stability and their corrosion resistance to the molten salt
Abstract High temperature stability of SPS YSZ coatings with the columnar and deep vertically cracked (DVC) structures and their corrosion resistance to 56 wt% V 2 O 5 +44 wt% Na 2 SO 4 molten salt mixture were investigated. Both the columnar and DVC structured YSZ coatings were sintered at 1000 degC, but a significant increase in porosity in combination with significant reductions in Vickers' hardness and Young's modulus were observed at the temperatures from 1200 degC to 1400 degC. The DVC structured YSZ coating exhibited superior corrosion resistance against the molten salt mixture attack to the columnar structured one due to its higher density behaving as a sealing protective top layer at 950 degC.