Induction Brazing of 304 Stainless Steel with a Metalloid-Free Ni-Zr-Ti-Al-Sn Amorphous Foil

The feasibility of a novel metalloid-free Ni57Zr20Ti17Al5Sn1 (at.%) amorphous filler metal for 304 SS brazing was investigated by induction brazing. The joining process can be completed within seconds in argon atmosphere due to the sensitive response of induction heating. The effects of joining time on the microstructure of joints and the joint shear strength were investigated. The results indicate that the joints brazed for 5 s and 10 s exhibit good wetting between the base metal and the filler metal. Overheating occurred due to skin effect for the holding time of 20 s. The brazed seam of 5 s is composed of Ni-rich phases while the brazed seam of 10 s is composed of Fe-rich phases indicating the gradual homogenization of the bonding region with the base metal as a function of holding time. Shear strength of as high as 235 MPa was obtained when brazed for 10 s.