Recent progress on the additive manufacturing of aluminum alloys and aluminum matrix composites: Microstructure, properties, and applications

Whilst the adoption of additive manufacturing (AM) of aluminum alloys is relatively slower compared with that of steels and titanium alloys, it has undergone a flourishing trend in the past 15 years. Significant progress, such as the development of novel processes, novel alloys, novel heat treatment profiles, and applications, has been made through the combined efforts from academic and industry fields. This state-of-the-art review presents a detailed overview of the process technology, microstructure, and properties of different aluminum alloys and aluminum matrix composites fabricated using various additive manufacturing technologies, including laser powder bed fusion, electron beam powder bed fusion, laser powder direct energy deposition, wire arc additive manufacturing, binder jetting, and additive friction stir deposition. The pros and cons of each technology in fabricating aluminum alloys are evaluated. As the dominant additive manufacturing technology for aluminum alloys, an emphasis is put on the laser powder bed fusion technology by reviewing the effect of various factors, such as post-heat treatment, powder feedstock, oxidation, and element evaporation, on the microstructure and properties. We close the review with the outlook listing the remaining challenges associated with the additive manufacturing of aluminum alloys.