An investigation on joining of Al6061-T6 to AZ31B by microwave hybrid heating using active braze alloy as an interlayer

Active braze alloy is used as an interlayer material to join AZ31B to Al6061-T6 by microwave hybrid heating. The phase compositions of the reaction layer and the microstructure aspects are investigated using Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray spectroscopy (EDX) and X-ray diffraction (XRD). Intermetallic compounds of Aluminum, Magnesium, Silver and Oxygen i.e. Mg55Al40Ag5, Al60Mg38Ag2, MgAl2O4 and TiO were found to be formed in the reaction layer. Hardness of intermetallic towards the aluminum parent material is high i.e. 4.31 GPa. This is due to the formation of intermetallic that are brittle and hard in nature. The tensile shear strength of the joint was evaluated. The formation of intermetallic compounds i.e. Al60Mg38Ag2, MgAl2O4 and TiO are responsible for the poor strength.