2002 Volume 45 Issue 4 Pages 504-509
Using two types of specimen that rolling direction was parallel and perpendicular to loading direction in film fatigue testing, effects of rolling texture on fatigue crack propagation properties in iron films of 100µm were discussed in relation with the grain size. A crystallographic analysis by EBSD (Electron Backscatter Diffraction) method showed that the anisotropy of rolling texture remained even in the films annealed at 873K and 1173K. The cracks in the film with the smaller grain size annealed at 873K propagated along the grain boundary and the crack propagation rate is approximately the same for both loading direction parallel and perpendicular to the rolling direction. On the other hand, the cracks in the film with the larger grain size annealed at 1173K propagated across the grain and the crack propagated slower toward the perpendicular direction to the rolling direction than toward the parallel direction. This is probably because the slip system of the rolling texture in a grain of the iron film annealed at 1173K is different in accordance with the relationship between rolling direction and crack propagation direction. Also, the rolling texture was outstandingly turned around the fatigue crack propagated perpendicular to the rolling direction in the film annealed at 1173K.