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In-Chamber Electron Beam Welding

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TWI provides in-vacuum-chamber electron beam (EB) welding and processing, such as brazing, as well as a range of related products and services.

Conventional EB welding takes place within a vacuum chamber, taking advantage of the clean environment to produce high-integrity, high-productivity and low-distortion welded joints. Electron beam welds are autogenous and hence result in the parent metal composition in the joint.

TWI is active in the development of new capability as well as deployment of established in-chamber EB welding at a range of power levels, including:

High power – welding of thick-section material using a high accelerating potential (up to 175kV) and high beam power (up to 100kW) to penetrate steel up to 300mm thick, while achieving a stable weld keyhole in sections of 200mm or more. Application fields are often in the power sector, nuclear waste encapsulation and for value-adding in primary manufacture. Stainless and carbon-manganese (C-Mn) steels as well as copper and nickel-based super alloys are commonly welded.

Medium power – the main users of EB welding are the aerospace and automotive sectors. Here weld penetrations are typically between 1 and 20mm. Welds in turbine engine drums, control actuators, heat exchangers, gear clusters and turbochargers are common; many oil and gas industry instrumentation assemblies are also welded/hermetically sealed. The process is beneficial as the resulting welds, having been made with a very localised heat source, which is consistent through the thickness being welded, typically have low distortion and allow parts to be welded at or very close to final size/geometry.

Low power – EB welding machines may be configured to produce very fine, intense beams with spot sizes at the workpiece as small as 20µm. These beams may be used effectively to create very small welds, cuts, holes and other features. Welding, as at higher powers, is a keyhole process; the subtractive processes are achieved through the use of pulsed beams which ablate and vaporise material in a controlled manner.

Other services include welding feasibility determination and detailed procedure development, as well as the provision of advanced equipment solutions and quality assurance tools such as BeamAssure™ and surface engineering technologies such as Surfi-Sculpt®.


  • Thickness range ( <0.1 to>200mm)
  • Single pass welding
  • Autogenous process (normally no filler)
  • Low heat input & distortion
  • Narrow, high aspect ratio, heat affected zone (HAZ)
  • High speed & productivity
  • Up to 100kW beam power
  • Non-contaminating atmosphere
  • Most metals and dissimilar combinations
  • Modelling and practice
  • Large welding chamber machines
  • Standards interpretation and application
  • Monitoring, quality assurance (QA) & calibration know-how

Applications & Services

  • Welding & brazing
  • Feasibility and procedure qualification
  • Low volume, very high value adding, specialist production welding
  • Applications in most industry sectors

For further information please see Joining Technologies or please email


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