Laser-beam powder bed fusion of Al-Fe-Cu alloy to achieve high strength and thermal conductivity

Laser-beam powder bed fusion (PBF-LB) technique was used to produce an Al-2.5 %Fe-2 %Cu ternary alloy, featuring a two-phase eutectic composition of alpha-Al/Al23CuFe4 in non-equilibrium solidification, as determined by thermodynamic calculations. The specimen manufactured by PBF-LB exhibited a high tensile strength exceeding 350 MPa and a low thermal conductivity of approximately 140 W m-1 K-1. Subsequent annealing at 300 degrees C improved the thermal conductivity to 175 W m-1 K-1 without compromising the strength. This improvement was attributable to forming numerous Al23CuFe4 nanoprecipitates, which consumed solute elements. By appropriately managing the factors contributing to strengthening, a superior strength-conductivity balance can be achieved by implementing post-heat treatments.