Original paper(Vol.47 No.7 pp.672)

Basic study of sintering behavior of zirconia thermal barrier coating

Itoh Yoshiyasu; Takahashi Masashi; Okamura Takanari; Nagata Kohsoku

Abstract:Thermal barrier coating (TBC) had been already applied to the hot section parts of gas turbines, such as a bucket and a combustor. It is thought that TBCs are in dispensable for the gas turbines along with cooling technology. It is now desired to give higher durability to TBCs so as to endure higher combustion temperature. The object of this study is to clarify the sintering behavior of Atmospheric Plasma Spraying zirconia TBC at high temperature.
The experimental results showed that the shrinkage of plasma sprayed zirconia coating became remarkable above 1300K. There was a tendency that the shrinkage increased with increasing heating temperature and heating time. It was also indicated that the linear shrinkage followed a 2/5 power time law. The Arrhenius type temperature dependence for the sintering rate constant was confirmed. Finally, the shrinkage stress behavior induced by the sintering was made clear by the simulation analysis.

Key Words:thermal barrier coating, zirconia, atmospheric plasma spray, MCrAlY bond coating, sintering, linear shrinkage, shrinkage stress