Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1576462 | Materials Science and Engineering: A | 2013 | 10 Pages |
Abstract
Microstructures required for superplasticity were fabricated by intermittent multipass friction stir processing (FSP) in a 6 mm 5086 aluminium alloy plate. Two processing parameters corresponding to two different heat inputs were used. Multipass FSP created a gradient microstructure with fine and coarse grain-depth features on the processed plates. Three sheets of 1.5 mm thickness with different microstructural features were extracted for deformation testing under superplastic conditions: a layer with only fine grains from the nugget layer (NL), a layer with a thermomechanical-/heat-affected layer containing coarse grains (TL), and a composite layer (CL) having both fine and coarse grains in equal proportions. High temperature tensile testing was conducted for different layers between 450-550 °C with strain rates ranging from 5Ã10â4 sâ1 to 1Ã10â2 sâ1 to determine the optimum superplastic conditions. The NL and CL were comparable in terms of ductility with a high m value of 0.44. The maximum ductility values were 325% for NL, 355% for CL and 230% for TL. The high ductility of the composite layers, despite their microstructural inhomogeneity, establishes multipass FSP as an effective bulk processing technique.
Related Topics
Physical Sciences and Engineering
Materials Science
Materials Science (General)
Authors
S. Pradeep, Vivek Pancholi,