Microstructural assessment and mechanical properties of electron beam welding of AlSi10Mg specimens fabricated by selective laser melting

Electron beam bead on plate and butt-welded specimens ((similar to)5 mm in thickness) built in the X and Z directions were investigated. The microstructure of welds in both bead on plate and electron-beam-welded specimens revealed a eutectic morphology with a very thin heat-affected zone. Increasing heat input resulted in reduced porosity of the joint and subsequent improvement of the mechanical properties. The yield strength and tensile strength of the joint region are similar to those of the base metal, i.e., 206 vs. 207.5 MPa and 310 vs. 322 MPa, respectively. The elongation of the welded metals was slightly reduced, as compared to that of the base metal. Fractography analysis revealed that for samples welded under optimal welding parameters, failure mostly occurred at the base metal. The results of a simulation of temperature distribution within the joint region were in a good agreement with observed macrostructural characteristics. Electron beam welding can be successfully used for joining AlSi10Mg parts fabricated by selective laser melting.