Distribution of residual stresses in EB-PVD thermal barrier coatings

EB-PVD遮熱コーティングを施した材料における残留応力分布

鈴木 賢治*; 菖蒲 敬久  ; 田中 啓介*

Suzuki, Kenji*; Shobu, Takahisa; Tanaka, Keisuke*

As a bond coating, CoNiCrAlY was pressureless plasma-sprayed on a substrate of nickel-base superalloy. As the top coating, zirconia with 4 mol yttria was coated by the electron beam-physical vapor deposited (EB-PVD) on the substrate which was rotating during coating. The rotation speed of the in-plane was 5, 10 and 20 rpm. The thickness of the top coating was about 0.12 mm. The distribution of the in-plane residual stress was measured by a conventional X-ray method. The distribution of the out-of-plane residual strain was measured by a strain scanning method with hard synchrotron X-rays. For the specimen with 20 rpm, the in-plane residual stress was small within the range from -20 to 30 MPa, the out-of-plane residual stress was a very small compression. A columnar structure of the EB-PVD thermal barrier coatings consists of the core part with a fourfold pyramid and the peripheral part with a feather-like structure.