Laser Metal Deposition of Aluminum Alloys 7075 and 5083 with the Addition of Volatile Alloying Elements through Powder Blending

Laser metal deposition (LMD) offers high flexibility in material selection. However, processing high‐strength aluminum alloys, like EN AW‐7075, remains challenging due to limited weldability and the evaporation of volatile alloying elements. In this work, solidification cracking is mitigated through grain refinement using TiC nanoparticle as nuclei. The evaporation of zinc and magnesium compromises precipitation‐hardening and solid‐solution‐hardening capacity and thus mechanical properties. This issue is addressed by in situ and ex situ powder blending with additional high Zn and Mg powders, such as ZnAl12 and AZ91. LMD of EN AW‐7075 results in losses of up to 65% Zn and 60% Mg, while EN AW‐5083 shows Mg losses of up to 35%. It is found that the majority of the additional Zn and Mg powders is lost through evaporation, necessitating increased additions. With an addition of 10% ZnAl12 and 5% AZ91, the EN AW‐7075 samples reach a composition according to the standard and are suitable for a heat treatment following T6. With an addition of 10% AZ91, the EN AW‐5083 samples reach a composition desired composition. This strategy highlights the potential for extending the range of processable aluminum alloys in additive manufacturing and opens pathways for the application of high‐strength alloys, such as EN AW‐7075.