| Title |
Thermal - Fatigue Failure Behavior of MCrAlY / ZrO2 - 8wt%Y2O3 Thermal Barrier Coating and Effects of the Laser Treatment |
| Authors |
진만복(Man Bok Jin); 이선호(Seon Ho Lee); 김종영(Chong Young Kim); 강춘식(Choon Sik Kang) |
| Abstract |
Isothermal and thermal fatigue tests were carried out for plasma sprayed and laser treated MCrAly/ZrO₂ 8wt%Y₂O₃ thermal barrier coatings(TBCs) to discuss the failure mechanism and the effects of laser-treatment. Phase transformation of the ceramic coating was not occurred during testing. In thermal fatigue test, at the temperature range of 1100℃∼RT, specimens were investigated prior to and after failure. Cracks initiated, grew and combined by stresses due to thermal expansion mismatch and oxidation of the bond coating near the bond/ceramic coating interface. So, failure of the TBC without laser-treatment occurred suddenly. In case of laser-treated TBCs, vertical cracks arisen from laser-treatment and cracks which initiated and grew near the interface-combined. But failure of the laser-treated TBC occurred gradually. Thermal fatigue Iife of the laser-treated TBC was increased 1.7 times than the TBC without laser-treatment. |