EB-PVD遮熱コーティングの熱サイクルによる内部応力

Internal stress in EB-PVD thermal barrier coatings under thermal cycle

鈴木 賢治*; 菖蒲 敬久  

Suzuki, Kenji*; Shobu, Takahisa

As the top coating, zirconia with 4 mol% yittria was electron beam-physical vapor deposited (EB-PVD) on the bond coating of CoNiCrAlY. The substrates were rotated during EB-PVD process and the rotation speeds were 5 (R5) and 10 rpm (R10). In order to investigate the change of the internal stress in the top coating by a thermal cycle, the specimen was heated from a room temperature to 1273 K, the internal stress was measured in-situ by the strain scanning method with hard synchrotron X-rays at each temperature step. For the specimen R5, the internal stress increased from about -100 MPa to about 100 MPa with the increase in temperature, then the stress relaxation of the top coating occurred over 1073 K. For the specimen R10, the internal stress did not show a tension in the heating process, it was caused by the separation between columnar structure.