Project Topic - Electron Beam Welding

Electron beam welding is a welding process that uses a beam of electrons to fuse two pieces of material. The electrons are "shot" at a high velocity at the work piece, and as the electrons hit the material their kinetic energy is converted to heat causing the materials to coalesce into one piece. This usually happens in a vacuum which creates an atmosphere that is easy to move and manipulate electrons through.

Key concepts in the process:

1. Fusion
2. Kinetic
3. Vacuum

The beam formation consists of several parts:

4. Emitter (a cathode that emits electrons)
5. Beam Generator (an anode which creates the beam)
6. Lens (two magnets that focus the beam)
7. Beam Deflector (positions the beam)

The welder itself consists of several parts as well:

1. Electron Gun (source of electron beam)
2. Working Chamber (vacuum chamber that holds the work piece)
3. Work piece Manipulator (positions the work piece)
4. Power Supply and Control/Monitoring Electronics)

The vacuum in which the weld occurs also creates an environment that protects the gun and creates a very clean weld with no oxidation. This means the weld can be very precise which is useful for a variety of applications. This precision along with the extreme density and energy of the electrons means that welds can be formed in a variety of ways. It is possible to create very narrow welds with deep penetration or wide welds with shallow penetration and anything in-between. This is controlled by the beam concentration and how it is focused.

This has several advantages:

1. Low heat input
2. Minimal heat affected area
3. No part distortion

This has several disadvantages:

1. Expense of equipment
2. Not very portable
3. Vacuum required

Electron beam welders are used in industries where high precision or complex welds are needed. Such industries include bio-medical and aerospace.