Effect of oligocrystallinity on damping and pseudoelasticity of oligocrystalline Cu-Al-Mn shape memory foams

作者:Li, H (Li, Hua)^[1 ]; Yuan, B (Yuan, Bin)^[1,2 ]; Gao, Y (Gao, Yan)^[1,2 ]; Zhao, YY (Zhao, Yuyuan)^[3 ]

Oligocrystalline Cu-Al-Mn shape memory foams with a pore size of 0.8-1.1 mm and a porosity of similar to 70% were prepared by the silica-gel beads infiltration method, subjected to long-time and cyclic heat treatments. The effect of grain size and oligocrystallinity (ratio of grain size to strut node diameter) on the damping and pseudoelastic properties of the foams were investigated. The peak damping increases with oligocrystallinity because a higher oligocrystallinity favors the martensite accommodation and mobility of phase interfaces during martensitic transformation. The low-amplitude martensite damping first increases and then decreases with increasing oligocrystallinity, because the martensite plates grow wider in larger grains with lower grain constraints, leading to fewer interfaces and lower damping. The high-amplitude martensite damping increases linearly with increasing oligocrystallinity, despite the wider martensite plates and reduced interfaces, indicating that the mobility of martensite plates for higher displacements is more favored by reduced grain constraints. The maximum recovery strain increases linearly with oligocrystallinity and a high value of 5.53% was achieved after cyclic heat treatment for 16 times, corresponding to an oligocrystallinity of 7.88. The high recovery strain results from the reduced triple junctions and grain boundary area due to grain enlargement that lowers the grain constraints. (C) 2018 Elsevier B.V. All rights reserved.

作者关键词:Cu-based shape memory alloy; Metal foams; Cyclic heat treatment; Grain growth; Grain constraints

KeyWords Plus:GRAIN-GROWTH; ALLOYS; BEHAVIOR; ALUMINUM; PORES; SIZE

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, Guangdong, Peoples R China
	[ 3 ] Univ Liverpool, Sch Engn, Liverpool L69 3GH, Merseyside, England   增强组织信息的名称     University of Liverpool

电子邮件地址:meygao@scut.edu.cn

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