Define principal process for electron beam machining, Mechanical Engineering

Assignment Help:

Define Principal Process for Electron Beam Machining

  • A beam of electrons is emitted from the electron gun which is basically following three points.

1. A cathode which is a hot tungsten filament (2500°c) emitting high negative potential electrons.

2. A grid cup negatively based with respect to the filament.

3. An anode which is heats at ground potential, and through which the high velocity electrons pass.

1358_Define Principal Process for Electron Beam Machining.png

  • The gun is supplied with electronic current from a high voltage D.C source.
  • The flow of electrons is controlled by the negative bias applied to the grid cup.
  • The electron passing through the anode is accelerated to two-third of the velocity of light by applying 50kv to 100kv at the anode, and this speed is maintained till they strike the work piece.
  • Due to the pattern of the electrostatic field produced by the grid cup, the electrons are focused and made to flow in the form of a converging beam through a hole in the anode.
  • A magnetic deflection coil is used to make the electron beam circular having a cross-sectional diameter of 0.01 to 0.02 mm and deflect it anywhere.
  • A built -in microscope with a magnification of 40 on the work piece enables the operator to accurately locate the beam impact and observe the actual machining operation.
  • As the beam impacts on the work piece surface the kinetic energy of high velocity electrons is immediately converted into the thermal energy and it vaporized the material at the spot of its impact.
  • The power density being very high (about 1.5 billion w/cm3) it takes a few microseconds to melt and vaporize material on impact.
  • The process is carried out in repeated pulses of short duration may range from 1 to 16,000 Hz and from 4 to 64,000 microseconds.

 


Related Discussions:- Define principal process for electron beam machining

Energy balance for a vapor stream, Write down the energy balance for a vapo...

Write down the energy balance for a vapor stream going through a throttling valve (a valve that just reduces the pressure).  State your assumptions. Suppose a nonvolatile materi

Couple, a couple can be balanced by a force equal to its magnitude?

a couple can be balanced by a force equal to its magnitude?

Thermodynamics, how to prove that heat and work is path function?

how to prove that heat and work is path function?

Preliminary stress analysis, Preliminary stress analysis work will start ea...

Preliminary stress analysis work will start early in the detail engineering phase after completion of equipment layout and piping study drawings. The piping required to be analyzed

Steam, what is dry ness fraction?

what is dry ness fraction?

Chemistry, what desaster made chemistry

what desaster made chemistry

Organization structure and design, Describe, using examples, what is meant ...

Describe, using examples, what is meant by job specialization, identifying it advantages and disadvantages.

What is a machine shop, A facility that uses machines to fabricate devices ...

A facility that uses machines to fabricate devices from stock raw materials or to change mechanisms based upon given specifications. Also, know as "Back" Shops. The common machi

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd