Application of thermal barrier coating in light weight gas turbine

Abstract

Application of thermal barrier coatings improves the performances than the previous design. Key failure areas of thermal barrier coatings are thermally grown oxide growth and ceramic coat sinter induced buckling and spallations. These coatings are in practice appearing in the forms of thick, thin, and duplex, laser surface re-melted, functionally gradient materials, and micro-laminations. The composite system of material evaluation responds the requirement of fatigue experiments for prediction of life. The comparative behavior of nickel base superalloys under different conditions of fatigue and influence of thermal barrier coating (TBC) were revised. Different types of fatigue mechanism experimentally simulate components exposed to services because the variable for interrelation of physical-thermal-chemical-mechanical phenomenon that prevails in system appears to be deficient. Hot section gas turbine implements are subjected to fluctuating stresses and temperature within aggressive environments. It results in combined fatigue, creep and oxidation of constituent materials. Studies of different types of high temperature fatigue of nickel base superalloys help us to understand the causes of failure and expectations of prediction of life. Generally nickel base superalloys are used in the form of single crystal, directionally solidified, powder metallurgy products, and polycrystalline cast/wrought alloys for different applications. The high temperature properties of these various forms make interesting usage within different high temperature and aggressive environments under stressed conditions. Gas turbines of either aerospace or electricity or diesel engine sectors are the consumers of these alloys. Thermal profiles of gas turbines are zones of interest for application. Additions of lightweight philosophies to the implements reduce the section thickness. Therefore evaluation of fatigue on these alloys under stipulation of simulation bears more attention. Creep interposition into fatigue theories has become the basis of interpretation. Till date experiences belong to empiricism, where the formulations require introduction of many suitable variables according to the system of exposure.