Abstract
Thermal barrier coating (TBC) of 8wt% Y2O3-ZrO2 was made by low-pressure plasma spraying. The coated film with 0.3mm in thickness was removed from the substrate of Nimonic-263 by electropolishing. Tension and compression tests of removed films were conducted by using a specially designed gap jig. TBC films showed stress relaxation while keeping the displacement constant both tensile and compressive deformation.
The X-ray method was used to measure the stress in the TBC film under bending. The stress measured by the X-ray method changed proportionally to the bending stress up to the magnitude of about 10MPa both in tension and compression. When the bending stress of about 20MPa was applied to the films, the X-ray stress did not increase because of sliding of the lamella structure. The sliding stress between lamellae was determined from the residual curvature of films after bending. It was about 10MPa, which agreed with limit stress measured by the X-ray method.
