Laser Powder Bed Fusion of an Al-Si-Zn-Mg-Cu alloy: Effect of the Silicon Content on the Consolidation Phenomena

Laser powder bed fusion (LPBF) is a powder bed additive manufacturing technology that allows the production of fully dense metal components taking advantage of melting thin layers of a metal powder. The LPBF process of aluminium alloys recently gained much interest, not only thanks to the high geometrical freedom, but also thanks to the peculiar microstructures and the enhanced mechanical properties it is possible to obtain. Despite this growing interest, up to now, only a few aluminium alloys are processable by additive manufacturing technologies. Most of the high strength aluminium alloys, such as the 7075, suffer in fact from a strong liquation cracking phenomenon. In the present work, the composition of the high strength 7075 alloy was modified by mixing a 7075 powder in different ratios with an AlSi10Mg powder. The correct composition allowed the production of crack free Al-Si-Zn-Mg- Cu samples characterised by promising mechanical properties.