Ultrasonic-Assisted Resistance Brazing of Magnesium and Aluminium Alloys Using Melt-Spin Solder Foils

Recently, MgZn(Al)-solders have shown high potential fort the ultrasonic-assisted joining of Mg and Al alloys. Process reproducibility resulting in a homogeneous microstructure without detrimental intermetallic phases as well as the correlation between microstructure and mechanical properties are not very well researched yet. By employing ultrasonic-assisted resistance brazing various Mg and Al alloys were joined using melt spin MgZn(Al) solder foils. Brazing temperature, ultrasonic duration, holding time and pressure were varied using DoE. XRD and SEM were employed to evaluate the microstructure. Bending strength, hardness and corrosion resistance were measured and compared. A process parameter optimisation was developed allowing for a controlled formation of a homogeneous microstructure and optimum mechanical properties. Well adapted solders and process parameters can be offered for various base materials shaped to individual industrial needs.