Friction stir processing (FSP) has been developed as a potential grain refinement technique. In the current study, a commercial 5083 Al alloy was friction stir processed with three combinations of FSP parameters. Fine-grained microstructures with average grain sizes of 3.5-8.5 µm were obtained. Tensile tests revealed that the maximum ductility of 590 was achieved at a strain rate of 3 x 10-3 s-1 and 530 °C in the 6.5-µm grain size FSP material, whereas for the material with 8.5-µm grain size, maximum ductility of 575 was achieved at a strain rate of 3 x 10-4 s-1 and 490 °C. The deformation mechanisms for both the materials were grain boundary sliding (m ~0.5) However, the 3.5-µm grain size material showed maximum ductility of 315% at 10-2 s-1 and 430 °C. The flow mechanism was solute-drag dislocation glide (m ~0.33) This study indicated that establishing a processing window is crucial for obtaining optimized microstructure for optimum superplasticity.


Materials Science and Engineering


National Science Foundation (U.S.)
United States. Department of Energy

Keywords and Phrases

Fine-Grained Microstructures; Friction Stir Processing; Tensile Tests

International Standard Serial Number (ISSN)


Document Type

Article - Journal

Document Version

Final Version

File Type





© 2004 Materials Research Society, All rights reserved.

Publication Date

01 Jan 2004