Consideration of cold metal transfer welding of AA5754 to galvanized steel from mechanical and microstructural aspects

In this study, overlap welding of AA5754 and galvanized steel sheets was carried out by cold metal transfer (CMT) method using ER4043 (AlSi5) filler wire. The effect of heat input on the formation of intermetallic compound (IMC) layer between steel and aluminum was investigated. Mechanical properties of the joints were determined by tensile and hardness tests and also applying nano indentation test to intermetallic layer. Chemical compositions of IMC were analyzed by EDX and the formation of Al7.2Fe1.8Si and Fe2Al5 phases was detected. Formation of Fe2Al5 phase was found detrimental for reliability of joint, although it's superior mechanical strength.