Hot corrosion, high temperature oxidation and thermal shock behavior of nanoagglomerated YSZ-Alumina composite coatings produced by plasma spray method

摘要

Hot corrosion, high temperature oxidation, thermal shock resistance and tensile strength of nanoagglomerated YSZ and YSZ-5, 10 and 15wt.% Alumina composite coatings produced by plasma spraying have been studied. Findings showed that hot corrosion resistance of YSZ-5 and 10wt.% Alumina composite coatings is higher than YSZ coating. After 21h of corrosion test, degradation of YSZ and YSZ-15wt.% Alumina coatings occurred at the interface of ceramic-bond coat while for YSZ-5 and 10wt.% Alumina coatings degradation occurred as spallation of the surface layers of coatings. After corrosion test the peak intensity ratio of t-ZrO_2/m-ZrO_2 for YSZ-15wt.% Alumina is higher than YSZ coating which shows better corrosion resistance of the former. Thermal shock and tensile strength test results showed a decrease in the shock resistance and tensile strength for YSZ-5 and 10wt.% Alumina coatings. High temperature oxidation of YSZ-Alumina coatings was higher than YSZ coating which shows that diffusion of O_2 through grain boundaries or defects as molecules or through vacancies in the lattice structure as ions has been limited.