About Additive Manufacturing
The 7 Categories of Additive Manufacturing
Although media likes to use the term “3D Printing” as a synonym for all Additive Manufacturing processes, there are actually lots of individual processes which vary in their method of layer manufacturing. Individual processes will differ depending on the material and machine technology used. Hence, in 2010, the American Society for Testing and Materials (ASTM) group “ASTM F42 – Additive Manufacturing”, formulated a set of standards that classify the range of Additive Manufacturing processes into 7 categories (Standard Terminology for Additive Manufacturing Technologies, 2012).
Vat polymerisation uses a vat of liquid photopolymer resin, out of which the model is constructed layer by layer. Find out more here.
Material jetting creates objects in a similar method to a two dimensional ink jet printer. Material is jetted onto a build platform using either a continuous or Drop on Demand (DOD) approach. Find out more here.
The binder jetting process uses two materials; a powder based material and a binder. The binder is usually in liquid form and the build material in powder form. A print head moves horizontally along the x and y axes of the machine and deposits alternating layers of the build material and the binding material. Find out more here.
Fuse deposition modelling (FDM) is a common material extrusion process and is trademarked by the company Stratasys. Material is drawn through a nozzle, where it is heated and is then deposited layer by layer. The nozzle can move horizontally and a platform moves up and down vertically after each new layer is deposited. Find out more here.
Powder Bed Fusion
The Powder Bed Fusion process includes the following commonly used printing techniques: Direct metal laser sintering (DMLS), Electron beam melting (EBM), Selective heat sintering (SHS), Selective laser melting (SLM) and Selective laser sintering (SLS). Find out more here.
Sheet lamination processes include ultrasonic additive manufacturing (UAM) and laminated object manufacturing (LOM). The Ultrasonic Additive Manufacturing process uses sheets or ribbons of metal, which are bound together using ultrasonic welding. Find out more here.
Directed Energy Deposition
Directed Energy Deposition (DED) covers a range of terminology: ‘Laser engineered net shaping, directed light fabrication, direct metal deposition, 3D laser cladding’ It is a more complex printing process commonly used to repair or add additional material to existing components. Find out more here.