Investigation of hot corrosion behavior of thermal barrier coating (TBC) systems with rare earth contents
Abstract
Thermal barrier coatings (TBCs) are extensively used to protect critical components such as aircraft turbines to provide thermal
insulation at elevated temperatures. At high operating temperatures, damage mechanisms such as oxidation and hot corrosion
result in spallation of TBC system. The spallation occurs due to the phase transformation during penetration of hot corrosion salts
to top coat. YSZ is mainly used as top coat material for TBC systems. However, YSZ cannot be used in temperature higher than
1000 °C. More superior efficiency of gas turbine engines will demand a new generation materials for TBC systems. Nowadays,
rare earth zirconates, Gd
2
Zr
2
O
7
,La
2
Zr
2
O
7
, YSZ/Gd
2
Zr
2
O
7
, and YSZ/La
2
Zr
2
O
used as ceramic top coat materials in gas turbine
engine components owing to their superior thermal isolation and hot corrosion resistance properties. In this study, hot corrosion
mechanism, rare earth zirconates, and their properties as well as their hot corrosion behavior in TBCs were investigated based on
literature studies.
