Figure 1. FSW setup, AS-advancing side, RS-retreating side, (a) AA8011-AS and (b) AA6082-AS.

The friction stir processed (FSPed) plates were cut with respect to the tests to be done using water-jet technology. The tests conducted were the microstructural analysis, tensile tests, hardness and fatigue tests. The microstructural analysis was performed using the metallurgical microscope. The specimens were grinded, polished and chemically etched prior the analysis. The chemical etchants used were the modified Keller’s reagent (10 ml HNO₃, 1.5 ml HCL, 1.0 ml HF and 87.5 ml distilled H₂O) and Weck’s reagents (1g NaOH, 4g KMnO₄ and 100 ml distilled H₂O). The Vickers hardness test was performed using the Falcon 5000 hardness testing machine through the guidance of ASTM E384-11 standard. The Hounsfield H25K tensile testing machine with Horizon operating software was used to perform the tensile tests. The ASTM-E8M-04 standard was used in designing tensile specimen and also the performance of the tests. The fatigue tests were conducted using the Instron 8801 (100kN) with Bluehill-3 operating software. The fatigue was performed based on the ASTM: E466-07 standard. The fatigue tests were conducted at a frequency of 20 Hz with the minimum and the maximum amplitudes of 30% and 80% of the ultimate tensile strength (UTS).