泡沫铝冶金连接及其界面结构与力学性能研究

以Zn-10Al合金作为粘结合金,采用功率超声辅助的热浸镀法进行泡沫铝板的冶金连接,采用光学显微镜(OM)和扫描电镜(SEM)观察接头组织及界面结构,采用X射线能谱仪(EDS)测定界面处元素分布,对样品进行拉伸实验和摆锤冲击实验,并与无功率超声辅助样品和胶接样品比较。功率超声辅助冶金接头密实连续,Zn、Al元素相互扩散,在界面处连续分布;无功率超声辅助接头中存在大量气孔等缺陷。功率超声辅助冶金接头的拉伸性能和冲击性能均优于无功率超声辅助接头和胶接接头。在功率超声辅助下进行连接时,其空化作用和声流能较彻底地破除泡沫铝基体表面的氧化膜,同时能够促进组织均匀化、去气除杂,有利于形成良好的冶金结合和致密的冶金接头。

Interfacial Characteristics and Mechanical Properties of Aluminum Foam Joined by Different Methods

Hot dipping method assisted by ultrasonic vibration was designed to join aluminum foam with Zn-10Al solder. Interfacial microstructure was investigated by OM, SEM and EDS. Standard tensile test and pendulum test were employed to examine the mechanical properties of the joints fabricated by different methods. Joints fabricated with ultrasonic vibration are compact and continuous while other joints fabricated without ultrasonic vibration have severe macro-defects. EDS analysis results show that the primary elements of filler alloy and the foam matrix diffused into each other and distributed continuously across the interface in the joint fabricated with ultrasonic vibration. Compared with joints fabricated without ultrasonic vibration or gluing directly with resin, the joints fabricated with ultrasonic vibration have much higher mechanical properties. It is believed that cavitation effect induced by ultrasonic vibration can remove the oxide film and refine the microstructure, which contributes to sound metallurgical bonding and compact joints.