Material positioning influence towards fatigue strength of the
friction stir processed AA8011/AA6082 joints
Mabuwa S1, Msomi V1*
1Cape Peninsula University of Technology, Mechanical
Engineering Department, Faculty of Engineering and the Built
Environment, P.O.Box 1906, Bellville, 7535, South Africa.
*Corresponding author: msomiv@gmail.com
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.
Keywords : Microstructural analysis, tensile properties,
microhardness, Fatigue, fracture surface morphology.