In-situ AFM Observation of Small Fatigue Crack Deflection behavior on alpha Brass

摘要

Fatigue crack growth test under constant amplitude loading was carried out on a brass. Successive observation of small fatigue crack growth behavior was performed by means of an atomic force microscope (AFM) equipped with small in-plane bending fatigue testing machine. Crack deflection and crack branching were observed frequently. They were resulted from the constraint of slip deformation due to strain hardening. The fatigue crack deflection behavior was investigated by the crystallographic orientation analysis based on the Electron Backscatter Diffraction (EBSD). It was found that the direction of crack deflection did not decided only by Schmid factor and depended on relative location between the preferential slip plane and crack front.