Effect of electropulsing on the fatigue resistance of aluminium alloy 2014-T6

The effects of electropulsing on the fatigue resistance of aluminium alloy 2014-T6 were studied in relation to electric current amplitude, pulse duration, and number of repetitions. Utilising the Taguchi method, the present study identified the current amplitude and the duration of the electropulsing as the two critical treatment parameters for improved fatigue resistance. A 97% fatigue life improvement was achieved under the electropulsing conditions that were applied. An increase in microhardness and a decrease in electrical conductivity due to electropulsing were correlated with enhanced fatigue resistance in the alloy. Mechanisms related to the effects of the electropulsing treatment were elucidated based on observations from scanning electron microscopy (SEM) and transmission electron microscopy (TEM) as well as numerical simulation results. The mechanisms identified by observation included dislocation movement and the secondary precipitation of GP-zones. Further explication of these mechanisms was provided by the application of a "magnetic field'' model.