2017 Volume 58 Issue 12 Pages 1647-1655
In this study, the method of high-pressure sliding (HPS) was applied for grain refinement of an A2024 alloy. Sheet samples with 10–15 mm width and 100 mm length with 1 mm thickness were processed by HPS under pressures of 2–3 GPa. Microstructural observations revealed that the grain size was refined to ~200 nm. Tensile tests showed that the ultimate tensile strength reached 886 MPa with a total elongation of 7.1% and the anisotropy of samples was less developed in the HPS-processed samples. Extra strengthening was attained by aging at 423 K after HPS processing, leading to an ultimate tensile strength of 967 MPa at the peak aged condition. Superplastic elongation of more than 400% appeared when the A2024 alloy processed by HPS for 20 mm was deformed in tension at a testing temperature of 623 K with an initial strain rate of 1.0 × 10−3 s−1.
This Paper was Originally Published in Japanese in J. Japan Inst. Met. Mater. 80 (2016) 593–601. In order to convey the results more precisely, Fig. 3 included the average hardness and the standard deviation for each sample. Miller indices were also added in the selected area electron diffraction patterns in Figs. 4, 10 and 13.