Microstructural influences on strengthening in a naturally aged and overaged Al-Cu-Li-Mg based alloy

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:637

Article

Ovri, Henry¹  Jaegle, Eric A.²  Stark, Andreas³  Lilleodden, Erica T.¹ 

[1] Helmholtz Zentrum Geesthacht, Inst Mat Res, Mat Mech, D-21502 Geesthacht, Germany

[2] Max Planck Inst Eisenforsch GmbH, Dept Microstruct Phys & Alloy Design, D-40237 Dusseldorf, Germany

[3] Helmholtz Zentrum Geesthacht, Inst Mat Res, Mat Phys, D-21502 Geesthacht, Germany

关键词: TEM;    APT;    Al-Li-Cu alloys;    Precipitates;    Strengthening mechanisms;   

DOI  :  10.1016/j.msea.2015.04.039

来源: Elsevier

【 摘 要 】

A combination of transmission electron microscopy, atom probe tomography and high-energy X-ray diffraction was employed to investigate the influence of local microstructural changes on strengthening in a commercial Al-Cu-Li-Mg based alloy, AA2198, in the stretched and naturally aged, and averaged states. Strengthening in the stretched and naturally aged temper was shown to be governed by a combination of Cu-Cu clusters, delta'/beta' phase and solution strengthening. This is in contrast to another report which suggests that strength in this temper is only due to Cu-rich clusters [B. Decreus, et al., Acta Mater., 61 (2013) 2207]. On the other hand, although large volume fractions of equilibrium phases such as T-B, and theta were present in the averaged temper, its strengthening was largely governed by order hardening, which is the strengthening mechanism associated with the delta'/beta' phase. The delta'/beta' phase remained in the matrix even after extensive averaging. (C) 2015 Elsevier B.V. All rights reserved.

【 授权许可】

Free