Superplastic deformation mechanism of an ultrafine-grained aluminum alloy produced by friction stir processing

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	Superplastic deformation mechanism of an ultrafine-grained aluminum alloy produced by friction stir processing
	Z. Y. Ma; F. C. Liu; R. S. Mishra
	2010
发表期刊	Acta Materialia
ISSN	1359-6454
卷号	58 期号:14 页码:4693-4704
摘要	An ultrafine-grained (UFG) Al-4Mg-1Zr alloy with a grain size of similar to 0.7 mu m with predominantly high-angle boundaries of 97% was produced by friction stir processing (FSP). The UFG Al-4Mg-1Zr retained submicrometer grains even after static annealing at 425 degrees C, and exhibited excellent superplasticity at 175-425 degrees C. High strain rate and low-temperature superplasticity of >1200% were observed at 1 x 10(-2)-1 x 10(-1) s(-1) and 300-350 degrees C. Even at 425 degrees C, a superplasticity of 1400% was achieved at 1 s(-1). A linear relationship between log (epsilon) over dot(opti) and T was observed (where (epsilon) over dot(opti) is the optimum strain rate, and T is the temperature). The analyses on the superplastic data revealed the presence of threshold stress, a stress exponent of 2, an inverse grain size dependence of 2, and an activation enemy of 142 kJ mol(-1). This indicated that the dominant deformation mechanism was grain boundary sliding, which was controlled by lattice diffusion. Based on this notion, a constitutive equation has been developed. A new superplastic deformation mechanism map for FSP aluminum alloys is proposed. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All
部门归属	[ma, z. y.; liu, f. c.] chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, peoples r china. [mishra, r. s.] missouri univ sci & technol, ctr frict stir proc, rolla, mo 65409 usa. [mishra, r. s.] missouri univ sci & technol, dept mat sci & engn, rolla, mo 65409 usa.;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	Superplasticity Friction Stir Processing Aluminum Alloys Ultrafine-grained Microstructure Strain-rate Superplasticity Low-temperature Superplasticity Mg-sc Alloy Zr Alloy Threshold Stress Al-alloy Creep Composites Growth Flow
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WOS记录号	WOS:000279845400011
引用统计	被引频次：129[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/31369
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	Z. Y. Ma,F. C. Liu,R. S. Mishra. Superplastic deformation mechanism of an ultrafine-grained aluminum alloy produced by friction stir processing[J]. Acta Materialia,2010,58(14):4693-4704.
APA	Z. Y. Ma,F. C. Liu,&R. S. Mishra.(2010).Superplastic deformation mechanism of an ultrafine-grained aluminum alloy produced by friction stir processing.Acta Materialia,58(14),4693-4704.
MLA	Z. Y. Ma,et al."Superplastic deformation mechanism of an ultrafine-grained aluminum alloy produced by friction stir processing".Acta Materialia 58.14(2010):4693-4704.