What Is an Electron Beam (EB) Welding Service?
An EB welding service is a welding process in which electrons emitted from an electron tube are accelerated using magnetic and electric fields to heat and melt a workpiece.
The cathode of the electron tube emits hot electrons when heated. This emission phenomenon is based on the same principle as that used in cathode-ray tubes.
The process of heating and melting by irradiating the workpiece with these hot electrons is basically performed in a vacuum.
The workpiece can be processed from thick to thin plates, and the welded area is characterized by the fact that distortion is unlikely to remain.
Recently, welding methods that can be performed in a low-vacuum environment and electron gun transfer type that emits electrons are also used.
Uses of EB Welding Services
A number of applications for EB welding services has been proposed for different materials.
- Materials that are difficult to weld using other welding methods
Dissimilar metal materials such as stainless steel and iron, stainless steel and copper, etc. - Hermetically sealed welded parts
Large structures such as pressure tanks and vacuum chambers, and cooling parts such as water-cooled jackets. - Parts for low distortion welding and high speed welding.
Automobile parts such as gears. - Materials that prevent oxidation of the workpiece surface during welding.
Active metal materials such as titanium and niobium. - Parts compatible with keyhole welding (deep penetration welding), thin weld bead (weld metal), and low distortion welding.
Metal materials with high thermal conductivity such as copper and aluminum.
Principle of EB Welding Services
When a cathode filament is heated in a vacuum, electrons are continuously emitted. The electrons produced here are called heat electrons.
The emitted electrons are accelerated by the high voltage (60 to 150KV) applied between the cathode and anode to form an electron beam.
This electron beam is focused by an electromagnetic coil and further controlled in the scanning direction by a deflecting coil to concentrate irradiation on a specific spot on the surface of the target workpiece.
The kinetic energy of the hot electrons impacting the workpiece is then converted into thermal energy, and the surface of the workpiece becomes so hot that it melts, completing the welding process.
The spot diameter of the EB welding services normally used is very small, approximately 0.2 mm, and the thermal effect applied to the periphery of the weld is minimal, so welding can be performed with little distortion remaining on the surface or inside of the metal.
By adjusting the output of the EB welding services, the range and depth of metal penetration can be controlled, enabling welding of a wide range of plate thickness materials, from thin to thick plates.