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Additive Manufacturing

Additive manufacturing (AM) is defined by ASTM as the 'process of joining materials to make objects, usually layer by layer, from 3D CAD data'. Additive processes include Selective Laser Melting (SLM), Laser Metal Deposition (LMD), Stereolithography, Fused Deposition Modelling (FDM) and 3D Inkjet Printing (3DP). Each technology is often distinguished by the raw materials used (including powder, wire, photosensitive liquid resins, thermoplastic filament, printing inks) or by the method of consolidation (including laser heating and melting, photo polymerisation, conduction heating, chemical reaction).

AM is seemingly opposite to subtractive manufacturing approaches that remove material to form the shape of a work piece.  The traditional metal removal processes such as milling, turning, grinding, electrical discharge machining (EDM), fall into this category.

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Part of TWI's focus is to promote the manufacturing freedoms offered by metal based AM technologies in industries such as aerospace, military and medical and to drive innovation on the complementary nature of both additive and subtractive processes. This could be the repair of turbine blades using Laser Metal Deposition, followed by grinding to finish contours.


TWI offers two advanced additive manufacturing technologies:

The experience of TWI staff and range of equipment housed at our Yorkshire facility, give the company an outstanding diversity in capability which is relevant across many applications and industrial sectors. These may include the manufacture of functional components, the modification and repair of high value components and the development of prototypes.


  • Trumpf 5-axis gantry CO2 laser deposition system

  • 7kW IPG Yb-fibre laser

  • Kuka robot based high deposition rate cell

  • Kawasaki robot based deposition cell

  • Realizer SLM 100 selective laser melting system

  • Renishaw AM250 selective laser melting system

The growth in production applications for AM technologies has been limited, in general terms, by several factors. Among them are:

  • Materials Selection

  • Process Performances

  • Cost (running costs, hardware and consumables), 

  • Design and Implementation

  • Impacts (i.e. Environmental)

The overriding industry challenge for metals based AM is to move the technology into a true manufacturing arena. TWI is determined to drive this forward by becoming involved in projects that develop procedures for processing of materials,  integration of different technologies for purposes of production and inspection i.e. integration of additive and subtractive manufacturing and non-destructive testing, and component optimisation for purposes of cost reductions or environmental impact (weight saving of high value aerospace components).

TWI also has expertise in Laser welding, Laser cutting, Hybrid laser arc welding, Nuclear decommissioningand Laser surfacing.

Further technical knowledge may be found here:  case studies,  published papers and  FAQs. 

If you require further information or have any questions please do not hesitate to  contact us.