Picture to Parts, One Thin Metal Layer at a Time

Abstract

Additive manufacturing is a process of manufacturing that creates a three-dimensional object by progressively depositing thin layers of material guided by a digital drawing. The creation of metallic objects using this technology is one of the fastest growing implementations, although other materials such as concrete, ceramics and polymers are also amenable to this manufacturing process, enabling applications that might not otherwise have been possible. Stainless steels, aluminium, titanium and nickel alloys in the form of powders or wires are melted by heating with a high-energy source such as a laser beam, electron beam or an electric arc. Metal printing is now used in aerospace, consumer products, health care, energy, automotive, marine and other industries because in cases where it has advantages over conventional methods. Here we examine the key processes and principles for printing metallic parts, their unique features, and review how their microstructure and properties develop. There are major challenges that need to be addressed for its continued expansion, requiring imagination and ingenuity to drive the future of metal printing.