Material positioning influence towards fatigue strength of the friction
stir processed AA8011/AA6082 joints
Abstract
The investigation on the fatigue behaviour of the processed friction
stir welded AA8011/AA6082 dissimilar joint is reported in this work. The
single-pass friction stir processing technique was applied on the
friction stir welded AA8011/AA6082 and AA6082/AA8011 dissimilar joints.
The friction stir processing was conducted under normal conditions (room
temperature). The samples were prepared for different analysis using the
waterjet cutter technology. The tests conducted include tensile,
microstructural analysis, microhardness, fatigue and fracture surface
morphology. The microstructural analysis revealed a correlation between
material positioning and grain sizes. There was a notable decrease in
grain size when AA6082 was positioned on the advancing side during
processing. The tensile properties of the joint processed with
AA6082/AA8011 were found to be higher compared to the joint produced
with AA8011/AA6082. The AA6082/AA8011 joint was found to be more ductile
compared to AA8011/AA6082 joint. The stir zone microhardness for the
AA8011/AA6082 and AA6082/AA8011 joints was measured to be approximately
60HV and 80HV, respectively. The fatigue strength of AA6082/AA8011 was
found to be higher compared to AA8011/AA6082 fatigue strength.