Deep Cup Forming by Superplastic Punch Stretching of Friction Stir Processed 7075 Al Alloy
Multiple overlapping passes of friction stir processing (FSP) were used to cover 80 mm wide region for punch stretching of 7075 Al alloy plate. The forming experiments were performed at 723 K. While a maximum depth of 52 mm (depth/punch diameter not, vert, similar 2.7) could be achieved by punch stretching at a slow strain rate of 10−3 s−1, the maximum depth obtained at a higher strain rate of 10−2 s−1 was 40.4 mm. However, tolerable variations in thickness can be maintained up to a depth of 18.5 mm which is nearly equal to the punch diameter. FEM simulation closely predicts the load and thickness variation till the point of initiation of cavities and instabilities.
I. Charit et al., "Deep Cup Forming by Superplastic Punch Stretching of Friction Stir Processed 7075 Al Alloy," Materials Science and Engineering A, Elsevier, Jan 2005.
The definitive version is available at http://dx.doi.org/10.1016/j.msea.2004.12.016
Materials Science and Engineering
National Science Foundation (U.S.)
University of Missouri Research Board
Keywords and Phrases
FEM Modeling; Friction Stir Processing; Punch Forming; Superplasticity
Article - Journal
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