A comprehensive overview of additive manufacturing aluminum alloys: Classifications, structures, properties and defects elimination

Aluminum alloys, known for their high strength, good toughness, and lightweight properties, are widely used in aerospace, rail transportation, and other fields. 3D printing, as an emerging additive manufacturing (AM) technology, achieves the transformation from digital models to physical products through layer-by-layer material deposition. This processing method significantly enhances the flexibility of both design and manufacturing, while also enabling the efficient production of complex piping and intricate cavity structures. This paper comprehensively and systematically introduces the classification, structure, performance, defects, and elimination methods of AM aluminum alloys. It begins with an introduction to AM technologies and traditional aluminum alloys. Then, it discusses the classifications and performances of AM aluminum alloys, such as Al-Si, Al-Mg-(Sc, Zr), Al-Cu-(Mg), Al-Zn-Mg-(Cu), Al-Fe, Al-Ni, Al-Mn, and Al-based composites, and providing a detailed and comprehensive overview of the mechanical properties (both in horizontal and vertical directions), heat resistance, fatigue performance, creep behavior, corrosion resistance, impact resistance, and wear resistance of the alloys. It also discusses the potential defects of different types of alloys and their mitigation methods, especially the formation mechanisms and elimination methods of porosity, deformation, and cracking. Moreover, the role of refiners in 3D-printed aluminum alloys is separately demonstrated. Finally, the paper presents the practical applications and prospects of 3D printed aluminum alloys, aiming to establish a systematic and comprehensive framework to provide a multi-faceted overview of aluminum alloys in AM, offering valuable insights and guidance for scientific research and industrial applications.