Formation and behavior of thermal barrier coatings
on nickel-base superalloys①
on nickel-base superalloys①
(1. Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, China;
2. School of Information, University of Science and Technology Beijing, Beijing 100083, China)
2. School of Information, University of Science and Technology Beijing, Beijing 100083, China)
Abstract: Plasma-sprayed thermal barrier coatings (TBCs) have been used to extend the life of combustors. Electron beam physical vapor deposited (EB-PVD) ceramic coating has been developed for more demanding rotating as well as stationary turbine components. Here 3 kW RF magnetron sputtering equipment was used to gain zirconia ceramic coatings on hollow turbine blades and vanes, which had been deposited NiCrAlY by cathodic arc deposition. NiCrAlY coating surface was treated by shot peening; the effects of shot peening on the residual stress are presented. The results show that RF sputtered TBCs are columnar ceramics, strongly bonded to metal substrates. NiCrAlY bond coat is made ofβ,γ′and Cr phases, ZrO2ceramic layer consists oft′andcphases. No degradation occurs to RF ceramic coatings after 100 h high temperature oxidation at 1 150℃and 500 thermal cycles at 1 150℃for 2 min, air-cooling.
Key words: magnetron sputtering; thermal barrier coating; shot peening; high temperature oxidation