Measurement of Crystal Orientation around the Fatigue Crack in Iron Films Using EBSD Method
Kenichi SHIMIZU, Tashiyuki TORII and Hirotaka OCHI
Abstract:Using a fatigue testing method by which fatigue cracks can be initiated and propagated in a film adhered to cover an circular through-hole in a base plate subjected to pull-pull cyclic loads, annealed rolled commercially-pure iron films of 100ƒÊm thickness were fatigued under constant stress amplitudes with a stress ratio of R = 0. In order to discuss correlation between fatigue crack propagation and change of crystal orientation, crystal orientation on the surface of the film materials was measured before and after fatigue testing. The crystallographic information of these films was analyzed using the Electron Back-scatter Diffraction (EBSD) system. As a result, the fatigue crack propagated not only along the boundary of crystal grains but also in a crystal grain and it was found that the scatter of crystal orientation around the fatigue crack on the films became larger after the crack initiation and propagation than before fatigue testing. Key Words:Fatigue, Crack, Iron Film, Crystal Orientation, EBSD Method