Ultrasound-induced liquid/solid interfacial reaction between Zn-3Al alloy and Zr-based bulk metallic glasses

Xingyi Zhang; Yong Xiao; Ling Wang; Chao Wan; Qiwei Wang; Hongchao Sheng; Mingyu Li

doi:10.1016/j.ultsonch.2018.03.006

Ultrasound-induced liquid/solid interfacial reaction between Zn-3Al alloy and Zr-based bulk metallic glasses

Ultrason Sonochem. 2018 Jul:45:86-94. doi: 10.1016/j.ultsonch.2018.03.006. Epub 2018 Mar 12.

Authors

Xingyi Zhang¹, Yong Xiao², Ling Wang³, Chao Wan³, Qiwei Wang¹, Hongchao Sheng⁴, Mingyu Li⁵

Affiliations

¹ School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China.
² School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China. Electronic address: yongxiao@whut.edu.cn.
³ China National Electric Apparatus Research Institute Co., Ltd., Guangzhou 510300, China.
⁴ Department of Materials Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China.
⁵ State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology Shenzhen Graduate School, Shenzhen 518055, China.

PMID: 29705329
DOI: 10.1016/j.ultsonch.2018.03.006

Abstract

Ultrasound-assisted fluxless brazing of Zr based Bulk metallic glasses (Zr-BMG) joint using Zn-3Al filler metal was performed in this study. The effect of ultrasonic vibration time on the microstructure and mechanical properties of Zr-BMG joints were investigated. Results showed that excellent metallurgic bonding could be obtained in ultrasonically brazed Zr-BMG joints. The interfacial reaction between liquid Zn-3Al filler metal and Zr-BMG substrate showed a mutation characteristic, which could be distinguished into incubation period and acceleration period. In the incubation period, Zn₅₀Zr₂₅Al₂₅ intermetallic compounds (IMCs) with small ellipsoidal shape were slowly formed and distributed randomly on Zr-BMG surface. However, in the acceleration period, Zn₅₀Zr₂₅Al₂₅ ellipsoids developed rapidly into a wavy-structured IMCs layer with a thickness of 17 μm, which was comprised of alternate Zn₅₀Zr₂₅Al₂₅ and Zn₂₂Zr sublayers. The microstructure evolution of Zn-3Al/Zr-BMG interface was ascribed to the combined effects of acoustic cavitations and Al element controlled interfacial metallurgic reactions. The average shear strength of joint was increased firstly then decreased slightly with increasing ultrasonic vibration time, and a highest strength value of approximately 100 MPa was obtained for joints brazed for 96 s. The shearing failure was inclined to occur at the Zn-3Al/Zr-BMG interface then transferred into the interfacial IMCs layer with increasing ultrasonic vibration time.

Keywords: Acoustic cavitations; Interfacial reaction; Shear strength; Ultrasound-assisted brazing; Zn-3Al alloy; Zr-BMG.