Development of lightweight Al-Mg and Al-Li based alloys via additive manufacturing using various gas mixtures
The GasAlloyX project, a collaboration between the TUM, Oerlikon AM, and Linde, investigated the effects of varying the process gas during the Powder Bed Fusion of Metals using a Laser Beam (PBF-LB/M) with a particular focus on aluminum alloys. Outcomes of the project include new aluminum alloy chemistries developed by Oerlikon AM, process stability enhancement utilizing helium-argon mixtures at Linde, and the development of a smooth-particle hydrodynamics (SPH) simulation framework to simulate melt pool dynamics at TUM. Hot cracking in 2000, 6000 and 7000 series Al alloys was successfully overcome in the PBF-LB/M parts via in-process formation of grain refining phases. These alloys are currently undergoing industrial qualification at Oerlikon. PBF-LB/M processing with helium was shown to increase material density compared to argon processing, with reduced process byproduct formation and a more stable energy input into the powder bed. Experimental observations validate the SPH model’s fidelity in predicting melt pool dimensions, morphology, and thermal gradient in the solidifying metal. This simulation framework is being extended to solid state phase transformations and microstructure prediction in the AMI GasAlloy-Y project.
Results
