TRNÍK Jaroslav Alexander Dubček University of Trencin

Spoluautoři KIANICOVÁ Marta, KAFRÍK Ján

Nickel-base superalloys are used in the aircraft turbines because of their superior properties and performance at high temperatures. Superalloys in such environments are limited from the view of their lowered resistance to the oxidation and corrosion impacts. This problem has been solved using protective coatings deposited on the surface of such engine components as turbine blades and they act as a diffusion barrier by creating thermodynamically stable oxide layer. There are other sources of loads imposed on turbine blades and vanes; centrifugal forces due to rotation, creep, low cycle fatigue and time varying thermo-mechanical fatigue due to sequential engine start-ups and shutdowns. Except oxidation and corrosion attack, the life of the coatings can be reduced by cracking caused by thermal and mechanical cycling due to poor mechanical behaviour of the coatings. The focus of the paper is on the study of thermo-mechanical fatigue behaviour of turbine rotor blades made from polycrystalline IN 713 LC with diffusion aluminide coatings under service conditions. This test revealed a few of fatigue cracks in the upper part of the layer but they were stopped by inner diffusion zone of the coating.