Development of an electron beam (EB) welding technique for additive manufactured (AM) AlSi10Mg
In recent years, Additive manufacturing (AM) processes such as Electron Beam Additive Manufacturing (EBAM) and Selective Laser Melting (SLM) have become more widespread in the production of industrial components with excellent dimensional tolerances and good mechanical properties. Limitations on the size of such parts, however, mean that robust and reliable techniques are necessary for joining AM components with conventionally manufactured complementary parts. Therefore, this study examines an electron beam welding (EBW) process for AlSi10Mg and investigates the results.
It is known that aluminium alloys processed by SLM show a higher porosity and are sensitive to the formation or redistribution of pores during welding processes compared to conventionally produced material. Such findings were confirmed by the experiments, and investigations were carried out to reduce porosity in the welded zone. Blind welding seams were produced by EBW on specimens generated by SLM, continuous, sand and die casting. The resulting samples were characterized by metallographic investigation of cross sections, hardness measurements and ultrasonic testing of the joints.
It was found that rapid beam deflection methods such as multi-spot or multi-process techniques can be applied successfully to reduce the formation of pores in the welding process. The porosity in the welding zone of the AM material could be decreased to the level of the base material. Other approaches like the removing of the porous surface layer of the AM part or preheating before the welding process did not result in a higher welding quality. The results show that additive manufactured AlSi10Mg may be welded using EBW techniques with high joint quality.