Microhardness
The Vickers microharness profiles of the friction stir processed FSWed joints are presented in Figure 4. The microhardness profile of the AA6082/AA8011 joint showed a decreasing path from the advancing side across the nugget zone (NZ) towards the reatreating side. The microhardness profile of AA8011/AA6082 joint showed a gradual increase from the advancing side towards the retreating side. The maximamum microhardness value of about 72 HV for AA6082/AA8011 joint was recorded next to thermos-mechanically affected zone (TMAZ) of AA6082. The maximum microhardness value of about 56 HV for AA8011/AA6082 joint was also recorded on the TMAZ region of AA6082. Both microhardness values of the friction stir processed joints were both lower compared to the base metals and this behaviour is normally associated with dissimilar aluminium alloyjoints [33-35].