Abstract
The bending fatigue tests were performed using the small sized microcantilever-shaped specimens of AZ31 magnesium alloy fabricated by the focused ion beam (FIB) processing to investigate the effects of the scale and the grain orientation on the fatigue behavior. The configuration of specimen was the rectangular cross section of 3μm x 8μm and the height of 40μm. For the fatigue test of small sized specimens, the fatigue testing apparatus was constructed by the piezo actuator and the high resolution microscope for controlling the very small displacement. The small sized specimens exhibited the higher fatigue strength than the bulk sized specimens. The fracture surfaces of the small sized specimens were flat, which were different from those of bulk sized specimens. By the investigation of grain orientation by the EBSD analysis, it was found that the stripe patterns observed on the surface of small sized specimen after the fatigue test were parallel to the basal sliding plane and the twin plane whose Schmid factor is high.
