Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9796637 | Materials Science and Engineering: A | 2005 | 10 Pages |
Abstract
Aluminum alloys, encompassed by AA 7055 alloy composition, having the nominal zinc content (i.e. 8 wt.%) but varying copper and magnesium contents across the alloy composition range were examined in the as-cast form by a combination of light microscopy, scanning electron microscopy (SEM), electron probe micro analysis (EPMA) and X-ray diffraction (XRD). It is observed that for all compositions, the second phases based on η(MgZn2), T(Al2Mg3Zn3) and S(Al2CuMg) are present. The T phase dissolves copper up to 28 wt.%, whilst the S phase shows metastable solubility of zinc that may range up to 30 wt.%. In alloys with magnesium at the lower limit and the copper contents approaching the upper limit of the alloy composition, the θ phase (Al2Cu) of the constituent binary Al-Cu system is further observed. The θ phase (Al2Cu) does not dissolve either zinc or magnesium. Below the nominal composition, the alloys could be homogenized substantially using a commercially viable homogenization treatment leaving small amounts of undissolved S phase that does not contain any zinc.
Related Topics
Physical Sciences and Engineering
Materials Science
Materials Science (General)
Authors
Chandan Mondal, A.K. Mukhopadhyay,