Process variants
- Electron beam basics - processes
- Scanned beam used for heating processes
- Window system used for in-air irradiation
- Non-vacuum nozzle type EB system
- Reduced pressure type EB system
- High vacuum type EB system
- High vacuum EB with beam deflection
Electron beam basics - processes
| a) full penetration EB welding | b) partial penetration EB welding |
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| c) EB drilling | d) EB texturing |
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Scanned beam used for heating processes |
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typical processes;
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Window system used for in-air irradiation |
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Electron beam is scanned over thin metal foil 'window', through which electrons penetrate into air. Substrates can be irradiated directly by high energy electrons as a continuous process. typical processes;
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Non-vacuum nozzle type EB system |
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The electron beam is projected into air via a series of nozzles.
The beam interacts strongly with air, so is best used at close distance (~<50mm) for processes that require the most intense beams. High powers (>60kW) are possible, but weld penetration is normally restricted to ~50mm by the beam/atmosphere interactions. NVEB processes include;
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Reduced pressure type EB system |
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The electron beam is projected into a 'reduced pressure' environment via a series of nozzles.
the beam only interacts weakly with the environment, so may be used at significant distance for many welding processes that normally require intense beams. Thick section welds can be narrow and deep, just like HVEB welds. Local sealing for the part is relatively easy: -small leaks may be tolerated. RPEB processes include;
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High vacuum type EB system |
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The electron beam is projected into a vacuum environment via a gun column that does not require nozzles per se. -usually a 'drift tube' suffices.
The beam barely interacts with the environment, so may be used at distance (~0.1 - 2m) for many processes that normally require intense beams. Thick section HVEB welds can be narrow and deep. HVEB processes include;
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High vacuum EB with beam deflection |
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A high vacuum EB generator is combined with a sophisticated beam deflection system and workpiece movement for processes such as texturing.
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Contact: electronbeam@twi.co.uk
Copyright ©2008 TWI Ltd
