Electron Beam Welding: Joining Two, or More, Dissimilar Materials
Continuous Electron Beam Welding (EBW) is a process whereby an electron beam is used to join two or more dissimilar materials, thicknesses, and tempers together in an edge to edge fashion. The resulting compound product provides performance that is not available in a single material.
The EBW process allows customers to stamp continuous coils of welded strip, rather than assemble individual components. In addition to reduced labor costs, reduced material costs are also realized by eliminating the scrap produced by a conventional milling or skiving process.
Electron Beam Welding can be used to join dissimilar metals and alloys, of both precious and non-precious metals. Fusing component materials with different thicknesses, tempers, tensile strengths and conductivities is no problem for this process. Even metals with dissimilar melting points can be welded by this method, including refractory alloys.
Used in many industries including energy management, consumer electronics and communications, typical Electron Beam Strip Welding applications include:
- High Power electrical contacts
- Metal strip resistors
- Switches and relays
- Spring contacts
- Applications not suited to skiving or milling (Stainless Steel)
- Automotive circuit breakers
- Thermostatic controls
- Medical devices
The Electron Beam Welding Process
High energy electrons, produced by a filament or cathode, are blasted at the metals to be joined. These electrons are accelerated using electrical fields and focused using magnetic fields, often in a vacuum environment to prevent scattering by stray gas molecules.
The impact of this directed stream of electrons generates heat which melts the parent metal, causing a small, fusion weld to be formed in that exact spot.
The resulting join is of very high quality and the localized heating means that there is minimal distortion of the rest of the metal around the weld area. Since it is carried out in a vacuum, potential impurities are eliminated or vaporized, making the resulting weld site very clean.
Welding is carried out in a continuous strip, producing weld depths from 0.05mm to up to 200mm without the need for a filler metal. Weld quality is exceptional and the method is highly efficient, controllable and reproducible, making it useful for high volume automated production.
Computerized control means that very fast welding speeds can be achieved, resulting in high process efficiency. The electron beam can also be used to selectively anneal a narrow zone along the length of the metal coil, if necessary.
Precision, custom-built fixtures are often necessary to support components prior to welding and CNC tables move parts to position them within the welding chamber. Over 30 years of experience in engineering design and providing Electron Beam Welding services means that Vincent Clad Metals are experts in planning and setting up tooling for every application.