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Arc Additive Manufacturing Services

Arc additive manufacturing, also known as wire arc additive manufacturing (WAAM) and directed energy deposition-arc (DED-arc), is a 3D printing-type production process that can be used to create parts by depositing layers of metal wire on a substrate.

WAAM processes use an electric arc to melt a metal wire feedstock and deposit it layer-by-layer to build a 3D object. It is a form of directed energy deposition (DED) that bears similarities to traditional arc welding, except it is automated by a computer-controlled robot or gantry system. It is a cost-effective manufacturing technique able to produce large-scale metal parts with a high deposition rate.

The process works as follows:

  • An electric arc is used to melt a metal wire which is then fed into the arc
  • The molten metal is deposited layer-by-layer on the substrate to build up the part according to a path defined by a 3D CAD model
  • A robotic arm or gantry system moves the welding torch to control the placement of the material to build the final component

Press Releases

Find out more about arc additive manufacturing at TWI:

Core Research Programme (CRP) and Joint Industry Projects (JIP)

Core Research

Each year the TWI Core Research Programme (CRP) addresses challenges on behalf of our Industrial Members as well as developing specific technologies and processes. Each of the projects under the CRP is focussed on engineering, materials or manufacturing technologies.

Find out more here

Joint Industry Projects

TWI also conducts Joint Industry Projects (JIPs) that bring together groups of Industrial Members to share the cost of research activities in areas of mutual industrial interest, gaining exclusive access to the outcomes. These projects cover a broad range of topics.

Find out more here

Advantages and Challenges

Arc-based additive manufacturing offers a number of benefits for industry:

  • High deposition rates: The speed of deposition makes the process suitable for making large components
  • Cost-effective: This process is typically less expensive than other metal additive manufacturing methods, as well as offering shorter lead times
  • Material efficiency: Creates less waste, using materials more effectively than traditional manufacturing methods

Despite the advantages of the process, there are also some challenges:

  • Surface finish: Parts created with this process often require post-processing, like machining, to achieve a smooth finish
  • Accuracy and precision: This process can provide less precision than others and issues with accuracy, such as stair stepping, can occur
  • Defects: Defects such as distortion and porosity can occur unless process parameters are optimise, impacting mechanical properties of the finished part

Wire Arc Additive Manufacturing at TWI

Wire arc additive manufacturing has proven popular due to the ability to produce very near net shape preforms without complex tooling, moulds or dies, which has created significant savings in cost and lead times, increased material efficiency, improved component performance and reduction of inventory and logistics costs from supply chains through local, on-demand manufacture.

The use of high quality computer-aided design and manufacturing (CAD/CAM) has seen this process advance significantly from its beginning in 1920, when it was first patented. As a process it sits between laser-based systems and plasma / electron beam systems when it comes to accuracy and speed.

Our expertise in WAAM systems means that we can provide advice and guidance on the application of arc-based additive manufacturing, including factors ranging from materials to heat input. We can advise on matters such as bead geometries, deposition parameters, residual stresses, surface finishing requirements, and the changing thermal field that occurs as a result of residual heat during the build process.

WAAM has proven to be an effective method for quickly creating parts from materials such as carbon and low alloy steels, stainless steel, nickel-based alloys, titanium alloys and aluminium alloys. TWI has experience in using the process for a range of different industry applications, including for aerospace where it has been shown to reduce time to market.

For more information please email:


contactus@twi.co.uk