| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1630551 | Journal of University of Science and Technology Beijing, Mineral, Metallurgy, Material | 2007 | 5 Pages |
Abstract
The ageing behavior of a pre-stretched thick plate of Al-Zn-Mg-Cu alloy was systemically studied including one-step ageing, two-step ageing, and retrogression and reageing treatment (RRA). One-step ageing of the alloy resulted in peak ultimate tensile strengths of 595 and 575 MPa after 22 and 6 h at 120 and 135°C, respectively. The strengthening phase in peak aged (T6 temper) alloy contained GP zones and the η' phase predominantly. After two-step ageing, the electrical conductivity was increased markedly, but the pre-stretched thick plate sacrificed a great loss of strength. RRA treatment provided a method for maintaining the strength close to that obtained by T6 temper and for obtaining the high electrical conductivity close to that obtained by T7 temper; the ultimate tensile strength and electrical conductivity were 583 MPa and 21.0 MS/m, respectively. TEM analysis of T7 and RRA specimens revealed two types of precipitates that contributed to age strengthening i. e. the η' and η phases.
Related Topics
Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
Zhihui Li, Baiqing Xiong, Yongan Zhang, Baohong Zhu, Feng Wang, Hongwei Liu,