Abstract
A previously undescribed high aspect ratio strengthening platelet phase, herein named the Y-phase, has been identified in a commercial Al-Zn-Mg-Cu alloy. Differential scanning calorimetry indicates that this phase only precipitates at temperature and cooling rate of about 150-250 °C and 0.05-300 K/s, respectively. This precipitate is shown to be responsible for a noticeable improvement in mechanical properties. Aberration corrected scanning transmission electron microscopy demonstrates the minimal thickness (∼1.4 nm) precipitate plates are isostructural to those of the T 1 (Al 2 CuLi) phase observed in Al-Cu-Li alloys. Low voltage chemical analysis by energy dispersive X-ray spectroscopy and electron energy loss spectroscopy gives evidence of the spatial partitioning of the Al, Cu and Zn within the Y-phase, as well as demonstrating the incorporation of a small amount of Mg.
Original language | English |
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Article number | 23109 |
Number of pages | 9 |
Journal | Scientific Reports |
Volume | 6 |
DOIs | |
Publication status | Published - 16 Mar 2016 |
Equipment
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Centre for Electron Microscopy (MCEM)
Peter Miller (Manager)
Office of the Vice-Provost (Research and Research Infrastructure)Facility/equipment: Facility