Fatigue Damage Assessment of Alternator Fans by EBSD

Components of new car alternators are subjected fatigue damage due to the start-stop cycles. Predicting their fatigue life still requires needs an experimental validation. Hence, identification of both monotonic and cyclic behaviour is required to integrate the right values in the models. Therefore a precise analysis of the dislocation arrangement produced by cyclic plasticty appears as a fatigue damage indicator. Here SEM-EBSD provide two plasticity markers: the Kernel Average Misorientation and the Low Angel Grain Boundaries that characterize dislocations arrangements in a quantitative way.Based on these indexes, the comparison between lab fatigue specimens and component gives an estimation of the local cyclic plastic strain.