Bonding mechanism of brazing of amorphous Cu-P filler metal

The copper joints were brazed with CuP 7.7 Sn5.4Ni14Si0.2Zr0.04 amorphous filler metal conventional filler metal respectively. The effect of the brazing temperature and time on the crystalline composition and microstructure of joints brazed with the amorphous brazing filler metal were compared and analyzed by micro-method. The results showed that the joints brazed with CuP7.7Sn5.4Ni14Si0.2Zr0.04 amorphous brazing filler metal consist of centre zone, interface area and diffusion zone. With the increase of brazing temperature and brazing holding time, the interface area brazed with both amorphous and conventional filler metal increases, and the microstructures of base metal and brazinrg seam centre zone would be coarsed. Excessively high brazing temperature or long brazing holding time will produce brittle phase, but this effect on amorphous filler metals is much smaller. Under the same conditions, amorphous filler metals interact with the base metal much more intensely than the corresponding conventional filler metals. The microstructure in interface area and centre zone of amorphous brazing seam are evidently uniform and small.