Machine Tools And Devices For Special Technologies

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Machine Tools And Devices For Special Technologies
Slovak University of Technology Faculty of
Material Science and Technology in Trnava

• Electron beam machining

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Material processing by electron beam

• High intensity of electron beam energy (109
  W/cm2),
• High speed of electrons (1,6 108 m/s),
• Small surface of impact (0,003 mm2),
• Electrons in the crash with particular atoms
  (molecules) of the base material transfer their
  energy.
• Depth of conjuction depth in that electron
  transfer completely their energy.

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Material processing by electron beam

• Electrons are essentially bigger than photons.
• More often crashes of electrons with air
  molecules.
• Electron beam conductivity straight decreased
  with distance that must be overcome by beam in
  the air.
• There is used vacuum room that conductivity will
  be not decreased.

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Principle of machining by electron beam

• Kinetic energy transmission in the impact to
  thermal energy.
• In the short time (?s) the small volume of
  material evaporated, steams are shoot out of
  becoming crater remainder of melting.
• Depth of conjunction is from some ?m to some
  tenths ?m.

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Principle of machining by electron beam
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Processing kinds by electron beam

• Cutting,
• micromachining,
• drilling,
• Marking, describing and engraving,
• welding,
• Thermal processing.

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Cutting by electron beam

• Relative movement between beam and workpiece is
  possible to securited
• Moving of the workpiece on the compound desk
  macromachining, trepanation of bigger holes,
• Deflection of electron beam by deflection reel -
  micromachining.
• Electron lithography engraving of mask on the
  workpiece surface before chemical processing
  (electronic component)

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Drilling by electron beam

• Small holes (?5 ?m) with high accuracy (1?m),
• Holes above ?0,25 mm beam tipping
• Bigger holes (above ?2-5 mm) trepanation
  accuracy 0,025 mm,
• They are used in production of filtre and riddles
  (big number of small holes). Fast production of
  accurately (dimensionally and positioning) holes.

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Drilling by electron beam

• number 25600
• diameter 0,55mm
• material anticorrosion steel

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Welding by electron beam

• Kinetic energy of impacted electrons is used for
  material melting,
• Possibility to chemical weld of active material
  in the vacuum room,
• Big depth of burnout,
• Minimum thermal influenced area,
• Needed continuous directing of beam energy from 0
  to maximum

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Welding by electron beam
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Device scheme

• 1 processing room,
• 2 compound desk,
• 3 workpiece,
• 4 electron canon,
• 5a cathode,
• 5b anode,
• 6 - Wehnelt electrode,
• 7 covering,
• 8 focusing reel,
• 9 deflecting reels,
• 10 connecting to vacuum pump,
• 11 electron beam,
• 12 deflecting electron beam,
• 13 input of high pressure

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Example of device
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Example of device
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Example of device