No abstract

No abstract

In this work, the development of AlZnMg(Cu) alloys was performed by thermodynamic simulations and experimental tests. With calculations, the solidification processes and phase compositions could be predicted. As secondary casting alloys, the selected compositions of AlZn4Mg3-Cu(Fe) and AlZn5Mg4Cu have higher contents of alloying elements, such as iron and silicon, and were successfully processed with a cold-chamber die casting machine. In addition, an energy-and time-saving optimization of the material properties was performed by a modified heat treatment (T6*) with a total time of only 12 h. The alloys were evaluated based on the characterization of their mechanical properties and the analysis of their microstructures. In particular, the elimination of cost-intensive alloying elements and the application of a modified heat treatment method clearly show the potential of AlZnMg(Cu) die-cast alloys for future industrial use.

No abstract

Wire arc additive manufacturing, employing conventional fusion welding processes, shows excellent versatility and can therefore be used for structural modifications of existing parts to create hybrid components. This study evaluates the modification of cold-formed AA2024 metal sheets with 2xxx filler metals to produce 2xxx hybrid structures. The alloys are investigated by thermodynamic simulations and the solidification crack susceptibility is assessed by calculating the index for hot cracking susceptibility. Using cold metal transfer, single-layer depositions are generated on profile sheets after which the specimens are characterised by three analysis procedures: metallographic analysis, chemical analysis, and hardness testing. Results indicate that AA2024 wire material, although generally considered difficult to weld, is more suitable for the additive modification of AA2024 sheets and profiles, as crack-free specimens can be deposited on cold-formed substrates.