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An investigation into the microstructure of friction-stir welded and artificially aged AA2017

Mirjalili, A ; Sharif University of Technology | 2013

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  1. Type of Document: Article
  2. DOI: 10.1007/s11665-013-0640-x
  3. Publisher: 2013
  4. Abstract:
  5. Microstructural changes in friction-stir welding (FSW) of artificially aged AA2017 were investigated. First, FSW was performed with rotational and linear speeds of 800 rpm and 40 mm/min, respectively. Then, microstructural studies by means of optical metallography and electron microscopy were conducted in different regions of the welded plates. Hardness testing was also employed to determine local strength and subsequent natural aging progress after welding. The results indicate that the considerable hardness degradation occurs in the thermo-mechanically affected zone owing to coarsening of semi-coherent precipitates. Grain refinement also takes place in the weld nugget as a result of dynamic recrystallization and it results in a fine-grained structure with the mean grain size to 5 μm. On the other hand, the initial precipitate distribution is completely vanished in the weld nugget and instead, spherical-shaped particles are formed. Moreover, natural aging after FSW occurs in the welded sample and leads to considerable increase in the hardness of the weld nugget zone
  6. Keywords:
  7. 2017 aluminum alloy ; dislocation network ; friction-stir welding ; microstructures ; precipitation ; Dislocation networks ; Fine-grained structure ; Micro-structural ; Microstructural changes ; Optical metallography ; Precipitate distributions ; Semi-coherent precipitates ; Thermomechanically affected zones ; Dynamic recrystallization ; Friction stir welding ; Grain refinement ; Grain size and shape ; Hardness ; Microstructure ; Precipitates ; Precipitation (chemical) ; Welded steel structures ; Welds ; Welding
  8. Source: Journal of Materials Engineering and Performance ; Volume 22, Issue 11 , 2013 , Pages 3566-3571 ; 10599495 (ISSN)
  9. URL: http://link.springer.com/article/10.1007%2Fs11665-013-0640-x