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.

在这项研究中，使用Zn-3Al填充金属对Zr基块状金属玻璃（Zr-BMG）接头进行了超声辅助的无助熔钎焊。研究了超声振动时间对Zr-BMG接头组织和力学性能的影响。结果表明，在超声钎焊的Zr-BMG接头中可以获得优良的冶金结合。液态Zn-3Al填充金属与Zr-BMG衬底之间的界面反应表现出突变特征，可以分为潜伏期和加速期。在潜伏期，小椭圆形的Zn ₅₀ Zr ₂₅ Al ₂₅金属间化合物（IMCs）缓慢形成并随机分布在Zr-BMG表面。但是，在加速期，锌₅₀ Zr ₂₅ Al ₂₅椭圆体迅速发展成波浪结构的IMC层，厚度为17μm，由交替的Zn ₅₀ Zr ₂₅ Al ₂₅和Zn _22组成Zr子层。Zn-3Al / Zr-BMG界面的微观结构演变归因于声空化和Al元素控制的界面冶金反应的综合作用。随着超声振动时间的增加，接头的平均剪切强度先增加，然后略有下降，对于钎焊96 s的接头，获得的最高强度值约为100 MPa。剪切破坏倾向于在Zn-3Al / Zr-BMG界面处发生，然后随着超声振动时间的增加而转移到界面IMCs层中。