Abstract
An aluminum alloy, 5083-0, was subjected to friction stir processing (FSP) with the aim of improving its room-temperature mechanical properties and realizing superplasticity in the high temperature region; a 6 mm thick rolling sheet of the alloy was used in the experiments. Further, various FSP conditions were employed to achieve microstructure refinement of the alloy. It was confirmed from the experimental results that the average grain size in the FSP region, i.e., the stir zone (SZ), decreased with a decrease in the frictional heat generated during FSP. Moreover, it was observed that the room temperature mechanical properties of the alloy in the SZ satisfied the Hall-Petch relationship. Further, annealing tests were conducted to investigate the thermal stability of the alloy in the SZ. The microstructure of the alloy in the SZ was apparently stable at temperatures below 723 K. Therefore, it was expected that high-temperature tensile tests conducted at temperatures below 723 K would be suitable for realizing superplastic elongation in the alloy. The above-mentioned results are briefly discussed in this paper.
