Laser-beam powder bed fusion of Al–Fe–Cu alloy to achieve high strength and thermal conductivity
Yue Cheng, T. Miyawaki, Wenyuan Wang, Naoki Takata, Asuka Suzuki, Makoto Kobashi, Masaki Kato
Abstract
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 α-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 low thermal conductivity of approximately 140 W·m−1·K−1. Subsequent annealing at 300°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.