Superplasticity of Friction-Stir Welds of Zr-Modified 5083 Aluminum Alloy with Ultrafine-Grained Structure

摘要

The commercial Zr-modified 5083 aluminum alloy was homogenized to precipitate nano-scale Al_6Mn particles and then undergone to equal-channel angular pressing (ECAP) at 300 ℃ to a true strain of～12 via B_C route. The obtained ultrafine-grained material was subjected to friction-stir welding (FSW). The welding variables were selected to provide reasonable homogeneous microstructure distribution across the weld zone and thus to ensure a highly uniform elongation during subsequent superplastic tests of the joints. Superplastic behavior of the obtained welds is discussed.