Assessment of alloys of the ternary Al-Cu-Ni system for application in Additive Manufacturing
Rapid Solidification, Laser Surface Remelting, Microstructure; Al-Cu-Ni alloys, Computational Simulation.
The manufacturing of metals and alloys via Additive Manufacturing (AM) has received special attention in recent years due to the possibility of obtaining parts with complex geometries, quickly and with minimal waste of raw material. Aluminum-based alloys are potential candidates for these processes, as well as of great scientific and technological interest, especially for application in the automotive and aeronautics industries. However, currently few there are Al-based candidate alloys for use in AM such as Al-12wt.%Si and Al-10wt.%Si-xMg. This occurs because such alloys are susceptible to the formation of pores, cracks, distortions and roughness, which affect high performance applications. The addition of Ni in Al-Cu alloys improves the mechanical properties at high temperatures and favors the reduction of the solidification interval, which results in a decrease in the amount of hot cracks and porosity in the final material. In this context, the present research seeks to investigate the microstructural changes and hardness of Al-5.0wt.%Cu and Al-4.0wt.%Cu-1.0wt.%Ni alloys processed via rapid solidification by centrifugation in a copper-mold and treated by Laser Surface Refusion (LSR) in order to reproduce similar AM process conditions (high cooling rates 103 - 108 K/s). The compositions were chosen from computer simulations in Thermo-Calc software. The microstructural characterization, in both processes, will be performed via optical microscopy (OM), with the calculation of dendritic (primary-λ1, secondary-λ2, tertiary-λ3) and eutectic (λe) spacings, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The mechanical behavior will be evaluated by Vickers microhardness tests.