Affiliation:
1. Army Institute of Technology, India
2. College of Engineering, Pune, India
3. Cummins India Ltd., Pune, India
Abstract
Thermal barrier coatings protect the substrate from thermal diffusion, oxidation, phase transformations, elastic deformation, plastic deformation, creep deformation, thermal expansion, thermal radiation. It allows parts and components of gas turbines to withstand high temperature upto1650 °C. Cylic oxidation behavior of alumina incorporated, lanthanum titanium aluminum oxide (LaTi2Al9O19), and yttria stabilized zirconia (YSZ), that is LTA/YSZ top ceramic layer coating, was investigated. Two coating combinations, L 100 having top LTA layer thickness of 100 µm and L 150 having top layer of LTA having thickness 150 µm, were tested for thermal cycles at the temperature of 1100°C. The performances of these coatings were compared with conventional YSZ coatings. Microstructure studies, EDX, and XRD analysis demonstrated the formation of mainly LTA, LaAlO3, Al2TiO5, Al2O3, and TiO2 at 1100°C in both coatings. But in L 150 coating, the rate of oxidation was found slower than L 100 coating. Annealed L 150A and L 100A specimens show cyclic oxidation life of 272th and 250th cycles, respectively.