In-Situ Atomic Force Microscopy and Crystallo Graphic Orientation Analysis of Small Fatigue Crack Deflection Behavior

Abstract

Successive observation of transgranular small fatigue crack growth behavior of alpha-brass was performed by means of an atomic force microscope (AFM) equipped with small in-plane bending fatigue testing machine. The fatigue crack deflection behavior, which was observed frequently in the low growth rate region, was investigated by the crystallographic orientation analysis based on the Electron Back Scatter Diffraction (EBSD) technique. The slip factor considering the slip system and singular stress field at the crack tip was introduced in order to evaluate the easiness of slip deformation instead of Schmid factor. The direction of crack deflection was found to be explained well by the slip factor and the geometric relative location between the preferential slip plane and crack front.