Secondary precipitation in an Al-Mg-Si-Cu alloy

被引：189

作者：

Buha, J.

Lumley, R. N.

Crosky, A. G.

Hono, K.

机构：

[1] Natl Inst Mat Sci, Tsukuba, Ibaraki 3050047, Japan

[2] Univ New S Wales, Sch Mat Sci & Engn, Sydney, NSW 2052, Australia

[3] CSIRO, Mfg & Mat Technol, Clayton, Vic 3169, Australia

来源：

ACTA MATERIALIA | 2007年 / 55卷 / 09期

关键词：

aluminium alloys; secondary precipitation; mechanical properties; TEM; 3DAP;

D O I：

10.1016/j.actamat.2007.01.006

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Interruption of a conventional T6 heat treatment at 177 degrees C for the Al-Mg-Si-Cu alloy 6061 after a short period of time (20 min), by inserting a dwell period at a lower temperature (e.g. 65 degrees C, promotes secondary precipitation of Guinier Preston (GP) zones. As a consequence, a much greater number of precursors to the beta" precipitates are produced so that a finer and denser dispersion of this phase is formed when T6 ageing is resumed. This change in microstructure causes significant and simultaneous improvements in tensile properties and fracture toughness. Secondary precipitation of GP zones occurs through a gradual evolution of a large number of Mg-Si(-Cu)vacancy co-clusters formed during the initial ageing at 177 degrees C. The precise mechanism of secondary precipitation has been revealed by three-dimensional atom probe microscopy supplemented by transmission electron microscopy and differential scanning calorimetry. (c) 2007 Acta, Materialia Inc. Published by Elsevier Ltd. All rights reserved.

引用

页码：3015 / 3024

页数：10

共 29 条

[1] Microstructural development and mechanical properties of interrupted aged Al-Mg-Si-Cu alloy [J].