Metal Additive Manufacturing Conference 2019

Beam-based additive manufacturing processes are widely used for producing components serving in several industrial applications, but only a few materials have been designed and optimized to bear the specific processing conditions offered by these technologies. Nowadays, a limited number of Al alloys are available on the market and employed for 3D printing of structural parts. Al-Si-Mg casting grades are the most common alloys for additive manufacturing, but they feature moderate mechanical properties. Through this research work, we studied the effect of different alloying elements on the processability by Selective Laser Melting (SLM) of Al-Mg-Cu high-strength alloys. A screening activity has been carried out by blending and processing Al alloy powders with different compositions. The ability of the modified alloys to respond to aging starting from as built and solution annealed conditions has been evaluated as well. The microstructure and phase transformations of the new alloy has been investigated by differential scanning calorimetry (DSC) and scanning electron microscope (SEM) analysis. The novel alloys processed by SLM featured a relative density higher than 99.8 % and were not susceptible to hot cracking phenomena. They also showed a good response to artificial aging, featuring yield strength and an ultimate tensile strength similar or even higher than those of high strength Al alloys produced by conventional casting processes.