中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 17 No. 4 August 2007 |
（School of Materials Science and Engineering, Beihang University, Beijing 100083, China）
Abstract:Yttria stabilized zirconia(YSZ) was deposited on the line cut β-NiAl substrate by electron-beam physical vapour deposition(EB-PVD), and the cyclic oxidation behaviors of thermal barrier coatings on β-NiAl substrate were investigated in 1 h thermal cycles at 1 200 ℃ in air. The results show that the samples fail after 80−100 cycles. Sub-interface cavitations in the substrate develop due to depletion of Al in forming thermally grown oxides(TGOs). The collapse and closing up of cavities result in the ragged YSZ/TGO/substrate interface. Since the specific crack trajectories are quite sensitive to local geometry, cracks along the YSZ/TGO/substrate interfaces ultimately lead to YSZ spallation.
Key words: EB-PVD; NiAl; TBCs; cyclic oxidation
