Heat treatment of 7xxx series aluminium alloys—Some recent developments  

7xxx系铝合金热处理的进展(英文)

作　　者：Paul A.ROMETSCH Yong ZHANG Steven KNIGHT 

机构地区：[1]Department of Materials Engineering, Monash University

出　　处：《Transactions of Nonferrous Metals Society of China》2014年第7期2003-2017,共15页中国有色金属学报（英文版）

基　　金：The Aluminium Corporation of China Ltd.(Chalco)for supporting aspects of this work financially;providing AA7150 materials as part of the Australia-China International Centre for Light Alloy Research(ICLAR);Monash University for developing the retrogression and reageing Matlab model (as part of the PhD project of Dr Adrian GROSVENOR);The ARC Centre of Excellence for Design in Light Metals and its Directors (first Prof Barry MUDDLE and then Prof Xin-hua WU) for supporting

摘　　要：The 7xxx series alloys are heat treatable wrought aluminium alloys based on the Al-Zn-Mg（-Cu） system. They are widely used in high-performance structural aerospace and transportation applications. Apart from compositional, casting and thermo-mechanical processing effects, the balance of properties is also significantly influenced by the way in which the materials are heat-treated. This paper describes the effects of homogenisation, solution treatment, quenching and ageing treatments on the evolution of the microstructure and properties of some important medium to high-strength 7xxx alloys. With a focus on recent work at Monash University, where the whole processing route from homogenisation to final ageing has been studied for thick plate products, it is reported how microstructural features such as dispersoids, coarse constituent particles, fine-scale precipitates, grain structure and grain boundary characteristics can be controlled by heat treatment to achieve improved microstructure-property combinations. In particular, the paper presents methods for dissolving unwanted coarse constituent particles by controlled high- temperature treatments, quench sensitivity evaluations based on a systematic study of continuous cooling precipitation behaviour, and ageing investigations of one-, two- and three-step ageing treatments using experimental and modelling approaches, in each case, the effects on both the microstructure and the resulting properties are discussed.7xxx系合金是基于Al-Zn-Mg(-Cu)系的可热处理的锻铝合金,广泛应用于高性能航空结构和运输部件。除了受成分、铸造和形变热处理影响外,材料性能的平衡明显受到其所经历的热处理方式的影响。描述了均匀化、固溶处理、淬火、时效对7xxx系高强合金组织和性能的影响。总结了在Monash大学进行的有关厚板产品的生产工艺,包括从均匀化到最终的时效处理,以及通过控制微观组织特征,比如弥散体、粗粒子、精细析出相、晶粒结构和晶界特征,来实现组织与性能的平衡。重点陈述了相关方法,如通过高温热处理溶解不需要的粗粒子、基于连续冷却析出行为的淬火敏感性变化、通过实验与建模来研究时效包括一步时效、两步时效、三步时效。对每种情况下的组织与性能都进行研究。

关 键 词：7xxx aluminium alloys AL-ZN-MG-CU HOMOGENISATION solution treatment quenching retrogression and re-ageing strength corrosion 

分 类 号：TG166.3[金属学及工艺—热处理]