Analysis of the Interfacial Reaction between Bulk Metallic Glass Coated Copper, Nickel, and Titanium with Lead-Free Solders

摘要

Bulk metallic glass (BMG) has good mechanical strength, high hardness, wear resistance, and corrosion resistance for use in sports tools, medical devices, and electronic equipment with promising applications in various industries. However, for the industrial production of BMG, the main issue is how to overcome the limitations of joining with other materials. The present study focuses on solder processing at a low operating temperature to avoid exceeding the recrystallization temperature. A feasible joining process for BMG was developed using lead-free solders. The BMG surface is pre-plated with copper, nickel, or titanium as a wetting layer. The reaction temperature is set between the glass transition temperature of BMG and the melting point of the solder. After a reflowing and aging process, the joint sample was examined using SEM, EDS, EPMA, and XRD. The Cu–Zr based BMG can be successfully joined with Sn-58Bi solder after plating Cu on the BMG surface. A diffusion layer was observed and the thickness increased with a longer aging time. The main components of the diffusion layer are ZrO 2 and Cu 10 Zr 7 .