Abstract
High temperature fatigue (R=0) damage and deformation behavior of SUS304 steel thermally sprayed with Al_2O_3/NiCr coating were investigated using an electronic speckle pattern interferometry(ESPI) method. Surface cracks and delamination occurred after 1x10^5 cycles test when σ_<max> was 202MPa at 873K. The lengths and number of cracks or delamination largely decreased when σ_<max> or temperature decreased to 115MPa or 573K, respectively. Strain values measured with the ESPI method along cracks were much larger than those in other areas due to crack opening under the tensile load. The positions of strain concentration zones on strain distribution figures measured by ESPI method corresponded well to those of cracks on sprayed coatings. Strain values decreased largely where local delamination occurred.
