Length-scale dependent microalloying effects on precipitation behaviors and mechanical properties of Al-Cu alloys with minor Sc addition

	Length-scale dependent microalloying effects on precipitation behaviors and mechanical properties of Al-Cu alloys with minor Sc addition
	Jiang, L; Li, JK; Liu, G; Wang, RH; Chen, BA; Zhang, JY; Sun, J; Yang, MX; Yang, G; Yang, J
刊名	MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
	2015
卷号	637 页码:139-154
关键词	Al-Cu alloy Microalloying effect Precipitation behavior Mechanical properties Length scale-dependence
英文摘要	Heat-treatable Al alloys containing Al-2.5 wt% Cu (Al-Cu) and Al-2.5 wt% Cu-0.3 wt% Sc (Al-Cu-Sc) with different grain length scales, i.e., average grain size > 10 mu m ( defined coarse grained, CG), 1-2 mu m (fine grained, FG), and <1 mu m (ultrafine grained, UFG), were prepared by equal-channel angular pressing (ECAP). The length scale and Sc microalloying effects and their interplay on the precipitation behavior and mechanical properties of the Al-Cu alloys were systematically investigated. In the Al-Cu alloys, intergranular theta-Al2Cu precipitation gradually dominated by sacrificing the intragranular theta'-Al2Cu precipitation with reducing the length scale. Especially in the UFG regime, only intergranular theta-Al2Cu particles were precipitated and intragranular theta'-Al2Cu precipitation was completely disappeared. This led to a remarkable reduction in yield strength and ductility due to insufficient dislocation storage capacity. The minor Sc addition resulted in a microalloying effect in the Al-Cu alloy, which, however, is strongly dependent on the length scale. The smaller is the grain size, the more active is the microalloying effect that promotes the intragranular precipitation while reduces the intergranular precipitation. Correspondingly, compared with their Sc-free counterparts, the yield strength of post-aged CG, FG, and UFG Al-Cu alloys with Sc addition increased by similar to 36 MPa, similar to 56 MPa, and similar to 150 MPa, simultaneously in tensile elongation by similar to 20%, similar to 30%, and similar to 280%, respectively. The grain size-induced evolutions in vacancy concentration/distribution and number density of vacancy-solute/solute-solute clusters and their influences on precipitation nucleation and kinetics have been comprehensively considered to rationalize the length scale-dependent Sc microalloying mechanisms using positron annihilation lifetime spectrum and three dimension atom probe. The increase in ductility was analyzed in the light of Sc microalloying effect and the strength contributions by different strengthening mechanisms was quantified as well. (C) 2015 Elsevier B.V. All rights reserved.
学科主题	Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering
类目[WOS]	Nanoscience & Nanotechnology ; Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering
收录类别	SCI ; EI
WOS记录号	WOS:000356207600017
公开日期	2016-05-03
内容类型	期刊论文
源URL	[http://ir.ihep.ac.cn/handle/311005/228430]
专题	高能物理研究所_多学科研究中心
推荐引用方式 GB/T 7714	Jiang, L,Li, JK,Liu, G,et al. Length-scale dependent microalloying effects on precipitation behaviors and mechanical properties of Al-Cu alloys with minor Sc addition[J]. MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING,2015,637:139-154.
APA	Jiang, L.,Li, JK.,Liu, G.,Wang, RH.,Chen, BA.,...&曹兴忠.(2015).Length-scale dependent microalloying effects on precipitation behaviors and mechanical properties of Al-Cu alloys with minor Sc addition.MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING,637,139-154.
MLA	Jiang, L,et al."Length-scale dependent microalloying effects on precipitation behaviors and mechanical properties of Al-Cu alloys with minor Sc addition".MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING 637(2015):139-154.