Conventional two-layered thermal barrier coatings （TBCs） are prepared by electron beam physical vapor deposition （EB-PVD） with ZrO2-8 wt% Y2O3 （8YSZ） as top coat and CoCrAlY as bond coat on disk-shaped Ni based ...Conventional two-layered thermal barrier coatings （TBCs） are prepared by electron beam physical vapor deposition （EB-PVD） with ZrO2-8 wt% Y2O3 （8YSZ） as top coat and CoCrAlY as bond coat on disk-shaped Ni based super-alloy. In this paper, three kinds of shot peening process with different lengths of operating time were adopted for bond coating. As a result, changes took place in its surface roughness and the surface micro-hardness. A thermal cycling test at 1 273 Kx55 rain and another at room temperature for 5 min were performed to study the effects of shot peening process on the thermal cycling lifetime of TBCs. It is found that a moderate shot peening process will be able to prolong the life time. The oxidation dynamic of the as-processed TBCs basically accords with the parabolic rule, and the oxidation test also attests to the spallation between YSZ and thermal growth oxide （TGO） responsible mainly for the failure of TBCs.展开更多
基金National Natural Science Foundation of China (50571005 50420130032)
文摘Conventional two-layered thermal barrier coatings （TBCs） are prepared by electron beam physical vapor deposition （EB-PVD） with ZrO2-8 wt% Y2O3 （8YSZ） as top coat and CoCrAlY as bond coat on disk-shaped Ni based super-alloy. In this paper, three kinds of shot peening process with different lengths of operating time were adopted for bond coating. As a result, changes took place in its surface roughness and the surface micro-hardness. A thermal cycling test at 1 273 Kx55 rain and another at room temperature for 5 min were performed to study the effects of shot peening process on the thermal cycling lifetime of TBCs. It is found that a moderate shot peening process will be able to prolong the life time. The oxidation dynamic of the as-processed TBCs basically accords with the parabolic rule, and the oxidation test also attests to the spallation between YSZ and thermal growth oxide （TGO） responsible mainly for the failure of TBCs.
