Control of Formation of Intermetallic Compound in Dissimilar Joints Aluminum-steel

Abstract

The elimination of the FexAly type phases was considered the solution to low ductility presented in aluminum-steel welded joints. Recently, the researches do not seek the suppression but the control of the thickness of these compounds. In this work, Al-Fe joints were manufactured by solid state and fusion welding, looking for controlling the formation of intermetallic compounds. Temperature measurements were carried out during the welding. The joints interface was characterized using optical and scanning electronic microscopy, aided by chemical composition measures with X-EDS. The microstructural characterization at the interface of aluminum-steel joints, in solid state welded joints, demonstrated the absence of intermetallic compounds, which is attributed to the low temperature reached during the process - less than 300 ° C. In the case of fusion joints, it has observed the permanent formation of intermetallic compounds whose thickness varies significantly with the heat input.