Achieving high oligocrystalline degree via strut architecture tailoring to increase the damping and mechanical properties of spherical porous CuAlMn SMAs

作者:Li, H (Li, Hua)^[1 ]; Yuan, B (Yuan, Bin)^[1,2 ]; Gao, Y (Gao, Yan)^[1,2 ]

Spherical and uniform CuAlMn shape memory foams (SMFs) with quasi-oligocrystalline microstructure and various foam structures were manufactured by the silica-gel beads infiltration method. The strut architecture was quantitatively characterized by strut node size N, strut length L and L/N, and the oligocrystalline degree of foams was characterized by grain size d over N (d/N) for the first time. d/N is found to increase linearly with L/N due to the constricted effect of complex strut architecture on two-dimensional grain growth. The coupling effect of strut sizes and oligocrystalline degree on properties of the SMFs was explored. Too thin struts (smaller N) result in higher quenching rate and consequently more quenched-in vacancies, hindering the thermal-induced martensitic transformation and low amplitude martensite damping. The peak damping becomes more dependent on d/N and tends to increase with increasing d/N, while the high-amplitude martensite damping improves linearly with d/N. The compression recovery strain also increases linearly with d/N under certain porosity, although higher porosity tends to compromise the favorable effect of higher d/N. The results demonstrate that higher d/N, which corresponds to higher oligocrystalline degree and lower grain constraints, favors the boundary mobility and martensite accommodation and thus improves the damping and compression recovery properties of Cu-based SMFs. (C) 2018 Elsevier B.V. All rights reserved.

作者关键词:Cu-based shape memory foams; Strut architecture; Grain constraints; Oligocrystalline microstructure

KeyWords Plus:SHAPE-MEMORY ALLOY; QUENCHED-IN VACANCIES; MARTENSITIC-TRANSFORMATION; METALLIC FOAMS; BEHAVIOR; PSEUDOELASTICITY; INFILTRATION; ALUMINUM; PORES; NITI

通讯作者地址:Gao, Y (通讯作者)

South China Univ Technol, Sch Mat Sci & Engn, Guangzhou 510640, Guangdong, Peoples R China.   增强组织信息的名称     South China University of Technology

地址:

	[ 1 ] South China Univ Technol, Sch Mat Sci & Engn, Guangzhou 510640, Guangdong, Peoples R China   增强组织信息的名称     South China University of Technology
	[ 2 ] Key Lab Adv Energy Storage Mat Guangdong Prov, Guangzhou 510640, Guangdong, Peoples R China

电子邮件地址:meygao@scut.edu.cn

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