Control of intermetallic compounds in Ultrasonic-Assisted Sn soldering of Mg/Al alloys. (November 2022)

• Record Type: Journal Article
• Authors: Liu, Yingzong; Bai, Yujie; Chen, Jintao; Chen, Hui; Zhu, Zongtao; Li, Yuanxing
• Is Part Of: Materials & design. Volume 223(2022)
• Publication Date: 2022-11
• Subjects: Ultrasonic-assisted soldering -- Mg2Sn -- Water-cooling -- Shear strength; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2022.111235
• Languages: English
• ISSNs: 0264-1275

Abstract

Graphical abstract: Highlights: The Mg2 Sn formation and growth was found mainly occurred during the cooling stage. The Mg2 Sn thickness was inhibited to less than 5 μm by using water-cooling. The joint strength was improved greatly with water-cooling than that of air-cooling. The fracture location changed from the IMC layer to the solder with water-cooling. Abstract: Magnesium and aluminum alloys are widely used in various industries because of their light weight and other properties. However, Mg–Al intermetallic compounds (IMCs) decrease the joint properties of Mg/Al, which limits its applications. Here, the alloys AZ31 Mg and 6061 Al are soldered together with Sn and Sn–9Zn solders though different cooling rates via ultrasonic-assisted soldering to control IMC formation and growth. Results show that this prevents formation of Mg–Al IMCs such as Al3 Mg2 and Al12 Mg17 ; however, Mg2 Sn forms in the soldered joints. The Mg2 Sn thickness increases with soldering temperature, which reduces joint strength. The thickness is reduced using the Sn–9Zn solder, and the effect of Zn is analyzed. With the use of water-cooling, the Mg2 Sn formation and growth are inhibited, the Mg2 Sn thickness is kept below 5 μm, and the shear strength peaks at 53.2 MPa. A soldering model of Mg2 Sn formation is proposed to reveal the evolution and inhibition mechanism of Mg2 Sn. This study well controls IMC thickness and improves joint strength, thus expanding industrial application of Mg–Al dissimilar metals and providing a feasible method for controlling IMCs in dissimilar metal joining.