SEM Investigations of Fatigue Crack Propagation in RR 58 Aluminum Alloy

Aluminum alloy RR 58 (AA 2618) has been viewed during exposure to cyclic loading, which is applied using a load frame inserted into a scanning electron microscope. Thus observation of surface interactions of the material microstructure with a propagating crack is feasible. Photomicrographs and (for the purposes of analysis and presentation) dynamic, real-time video-recordings used to document the processes will be displayed and the nature of the observations presented in relation to existing physical understanding of fatigue. Some additional ideas will be included based on the results presented herein.