Additive Manufacturing (AM) refers to a process by which digital 3D design data is used to build up a component in layers by depositing material. This definition is taken from the International Committee F42 for Additive Manufacturing Technologies (ASTM). The term “3D printing” is increasingly used as a synonym for AM. However, the latter is more accurate in that it describes a professional production technique which is clearly distinguished from conventional methods of material removal. Instead of milling a workpiece from solid block, for example, AM builds up components layer by layer using materials which are available in fine powder form. A range of different metals, plastics and composite materials may be used. This group of technologies include Selective Laser Melting, Direct Metal Laser Sintering and Laser Cusing among others.
ASTM has identified distinct process types: Material Extrusion, Powder Bed Fusion, Material Jetting, Binder Jetting, Directed Energy Deposition, Vat Photopolymerisation and Sheet Lamination.
Each process starts with the digitisation of the product idea, either through CAD modeling or reverse engineering, a 3D model of the idea is generated. From here the model is split into very thin slices which, when added together, make up the product design. These different processes all have one thing in common; they produce products in an additive way. Through laying down material, usually in successive layers from the bottom up, they are able to effectively “grow” parts rather than machining away material or using dies and molds. In metal Additive Manufacturing processes a very thin layer of the chosen material in powder form is dispersed over a building platform. High power lasers then melt the powder, rapidly scanning the surface of the material, thus fusing the powder according to the 3D model data. This process is repeated until layer by layer the final component is complete. There is very little material wastage, no tooling and very short CAD to part lead times.
What does Additive Manufacturing mean to customers? It could mean reduced costs, rapid production and material savings. Additive Manufacturing can potentially reduce part count by removing the need to join separate components by creating your product in a single piece.