Life Enhancement of Gas Turbine Combustor Liner Through Thermal Barrier Coating

The life enhancement program of an aero gas turbine combustor liner has been taken up through thermal barrier coating. Yttria-stabilized zirconia with a composition of Zr₂O₂ + 8 wt.% Y₂O₃ has been applied by atmospheric plasma spray on newly manufactured liner. A remarkable improvement in liner life has been observed under severe service condition. However, peel off of coating is noticed on the serviced components which are premature withdrawn for any other reasons. Reason for peel off has been studied metallurgically in detail. Coated samples were subjected to cross-sectional microanalysis. Based on the microanalysis suitable repair procedures are being adopted for serviced components. The process found very effective for a better life.