Growth mechanisms of interfacial compounds in arc brazed galvanised steel joints with Cu 97 Si 3 filler

Abstract

Galvanised steels have been joined using an arc brazing process with Cu₉₇Si₃ as the filler metal. The arcing time ranged from 1 s to 5 s with arcing current of 70 A in flowing argon. Excellent wetting between the base materials and the filler was observed for all samples. The reaction and products were confirmed by analysis of possible reaction products at the interface using thermodynamics, SEM, and EDS methods. From this, the schematic cycle of the interface Fe/Si compound growth mechanisms and fragmentation mechanisms of a whiskerlike intermetallic compound were determined. It has also been observed that Fe₅Si₃(Cu) particles are most likely to be generated at the interface through ‘dissolve separation’ ‘whiskerlike compound fragmentation’, and ‘anode spot action’ methods in the present arc brazing process.