Joining of aluminium alloy and galvanized steel using a controlled gas metal arc process

A precise control of the heat input is needed to restrict the development of Fe-Al brittle intermetallic compounds along the joint interface and the growth of the interface layer in mixed-material joints of aluminium and galvanized steel sheets. A novel study is presented here on the joining of aluminium alloys and galvanized steel sheets using a gas metal arc process with short-circuiting metal transfer and fast responsive control of current and voltage pulses. The influence of the processing conditions on the heat input, phase layer thickness, type of intermetallic compounds and joint strength is studied extensively. The permissible heat input is found to be in the range of 36-106 J mm−1 that has led to 0.68-6.10 μm thick phase layers along the joint interface with the maximum joint strength of 208 MPa.