Comparison of four arc welding processes used for aluminium alloy cladding

Metal inert gas (MIG), pulsed MIG, cold metal transfer MIG (CMT) and tungsten inert gas (TIG) welding processes were employed to produce clads. The cladding operations were analysed by an infrared thermal imaging technique and beads were characterised by X-ray radiography, neutron diffraction and microhardness mapping. Surprisingly, the CMT process produces the highest temperatures, but also the highest cooling rate. The MIG processes produce more residual stress and defect than TIG process.