Optimizing the strength and ductility of fine structured 2024 Al alloy by nano-precipitation
Optimizing the strength and ductility of fine structured 2024 Al alloy by nano-precipitation
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DOI：
10.1016/j.actamat.2007.06.043
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发表时间：
2007-10-01
期刊：
影响因子：
9.4
通讯作者：
Ma, E.
中科院分区：
文献类型：
--
作者：
Cheng, S.;Zhao, Y. H.;Ma, E.
晶粒或亚晶粒组织细化到1 μ m或更小的合金通常具有高强度，但拉伸延展性往往不足。过去在改善其延展性方面的努力通常导致强度的牺牲。我们已经开发出一种有效的方法，在实现高强度和高延展性的2024铝合金。该方法包括固溶处理以部分溶解T相颗粒，低温轧制以产生含有高密度位错和亚微米亚晶粒的精细结构，以及时效以产生高度分散的纳米沉淀物。研究发现，残余T相颗粒使其在冷轧过程中非常有效地积累位错，这反过来又促进了纳米级S'沉淀物的析出，其颗粒间距仅为10-20 nm。如此高密度的S'析出物使得有效的位错钉扎和积累成为可能，导致强度、加工硬化能力和延展性的同时增加。(C)2007 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
Alloys with grain or subgrain structures refined down to I mu m or below usually have high strength, but often inadequate tensile ductility. Past efforts in improving their ductility have usually led to a sacrifice of strength. We have developed an effective approach in achieving both high strength and high ductility in a 2024 Al alloy. The approach involves solution-treatment to partially dissolve T-phase particles, cryo-rolling to produce a fine-structure containing a high density of dislocations and submicrometer subgrains and aging to generate highly dispersed nano-precipitates. It was found that the remnant T-phase particles made it very effective in accumulating dislocations during cryo-rolling, which in turn promoted the precipitation of nanosized S' precipitates with an interparticle spacing of only 10-20 nm. Such a high density of S' precipitates enabled effective dislocation pinning and accumulation, leading to simultaneous increases in strength, work-hardening ability and ductility. (C) 2007 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.