Development of Flux and Filler Metal for Brazing Magnesium Alloy AZ31B

Abstract

This study was carried out to develop the flux and filler metals that enabled brazing a magnesium alloy plate of AZ31B at the temperature lower than 490°C. The following results were obtained in this study.
The newly developed flux that consisted of CaCl₂, LiCl and NaCl containing Ca ion and Li ion could successfully removed the oxide film from the magnesium alloy surface at around 450°C, and enabled us to braze the magnesium alloy at the temperature lower than 490°C.
In addition, we were successful in developing the brazing filler metal with the melting temperature lower than 480°C that consisted of magnesium and indium as a main component and a small amount of zinc to lower the melting temperature.
A joint with high strength equivalent to the base metal one was achieved using the above flux and the filler metal with little zinc, and the joint strength decreased with the increase in the zinc content.