Influence of anisotropy and post-fabrication heat treatment on the mechanical behavior of an 2xxx aluminum alloy obtained by additive manufacturing

This study evaluated the influence of anisotropy and post-manufacturing aging heat treatment on the microstructure, tensile strength, hardness, fracture toughness, and fatigue crack growth resistance of an AA-2319 aluminum alloy produced by additive manufacturing. The material was manufactured using the DED-Arc process with a MIG energy source and pulsed arc metal transfer mode. Build orientation, loading direction and notch position were combined to assess anisotropic mechanical behavior in two configurations (TL and LT), according to the ASTM standards. Specimens were tested in both the as-manufactured condition and after a T6 heat treatment commonly applied in the aluminum industry to maximize tensile strength. Microstructural analysis revealed deposited layers with associated heat-affected zones, an α-Al matrix grains, porosity, and θ’ and θ precipitates which were finer and more homogeneously distributed after aging. The aged condition Improved mechanical properties. Anisotropy was observed across all evaluated properties, with superior performance in the TL orientation compared to LT orientation.