Hardness recovery mechanism in the heat-affected zone during long-term natural aging and its influence on the mechanical properties and fracture behavior of friction stir welded 2024Al-T351 joints

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	Hardness recovery mechanism in the heat-affected zone during long-term natural aging and its influence on the mechanical properties and fracture behavior of friction stir welded 2024Al-T351 joints
	Z. Zhang; B. L. Xiao; Z. Y. Ma
	2014
发表期刊	Acta Materialia
ISSN	1359-6454
卷号	73 页码:227-239
摘要	The microstructural evolution in the heat-affected zone (HAZ) of 5 mm thick friction stir welded (FSW) 2024Al-T351 joints during long-term natural aging and its effect on mechanical properties were investigated by a combination of transmission electron microscopy, atom probe tomography, differential scanning calorimetry and mechanical property tests. FSW thermal cycle resulted in two low hardness zones (LHZs) in the HAZ: LHZ I, near the nugget zone (NZ), with grain coarsening and the dissolution of Guinier Preston-Bagaryatsky (GPB) zones and solute clusters, as well as the formation and coarsening of S (Al2CuMg) phases; and LHZ II, far from the NZ, with the dissolution of GPB zones and solute clusters. After 4-12 months of natural aging, the hardness recovered in the LHZ II due to the increase in number densities of Cu-Mg, Cu and Mg clusters, while there was no obvious change in the microstructure and hardness in LHZ I. The tensile strength of FSW 2024Al-T351 joints increased as the welding speed increased from 100 to 400 mm min(-1) and was weakly enhanced by the long-term natural aging, but was independent of the rotation rates from 400 to 1200 rpm. The FSW joints fractured along LHZ I under a low welding speed of 100 mm min(-1). With the increase of the welding speed and the prolongation of natural aging time, the joints fractured at LHZ I, LHZ II or the interface of the NZ/thermo-mechanically affected zone. The variation in the fracture locations was rationalized based on the microstructural evolution. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
部门归属	[zhang, z. ; xiao, b. l. ; ma, z. y.] chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, peoples r china. ; ma, zy (reprint author), chinese acad sci, inst met res, shenyang natl lab mat sci, 72 wenhua rd, shenyang 110016, peoples r china. ; zyma@imr.ac.cn
关键词	Aluminum Alloys Friction Stir Welding Aging Mechanical Properties Microstructure Cu-mg Alloys Aluminum-alloy Tensile Properties Welding Parameters Reaction-kinetics 2024-t3 Aluminum Microstructure Precipitation Strength Clusters
URL	查看原文
语种	英语
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/73509
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	Z. Zhang,B. L. Xiao,Z. Y. Ma. Hardness recovery mechanism in the heat-affected zone during long-term natural aging and its influence on the mechanical properties and fracture behavior of friction stir welded 2024Al-T351 joints[J]. Acta Materialia,2014,73:227-239.
APA	Z. Zhang,B. L. Xiao,&Z. Y. Ma.(2014).Hardness recovery mechanism in the heat-affected zone during long-term natural aging and its influence on the mechanical properties and fracture behavior of friction stir welded 2024Al-T351 joints.Acta Materialia,73,227-239.
MLA	Z. Zhang,et al."Hardness recovery mechanism in the heat-affected zone during long-term natural aging and its influence on the mechanical properties and fracture behavior of friction stir welded 2024Al-T351 joints".Acta Materialia 73(2014):227-239.