Friedrich Wilhelm Bach, A.
In this process, the material is removed with the help of a high velocity travelling at half the speed of light, i. These heat and raise the temperature locally above the boiling point and thus melt and vaporise the work material at the point of bombardment.
The electrons are obtained in free state by heating the cathode metal in vacuum to the temperature at which they attain sufficient speed for escaping to the space around the cathode. These can then be made to move under the effect of electric or magnetic field and can be accelerated greatly.
The acceleration is carried out by electric field, and focusing and concentration is done by controllable magnetic fields. The heat is produced below the transparent layer and in very small zone around impinging point of electrons.
Total penetration range can be estimated as: It is found that if the applied voltage be in the range of to volts then the electron velocity would be in the range of the velocity of light and under that condition electrons are having a high amount of kinetic energy.
When these electrons reach the anode surface, a rapid change in momentum takes place through collisions with the atoms of metal and thus a lot of concentrated thermal energy is obtained, which can be easily controlled.
Thus in this process there is no tool pressure or tool wear.
By this process fine gas orifices, wire drawing dies, turbine blades for supersonic aero engines, metering holes in injector nozzles can be fabricated.
Due to electron bombardment, the electrons of the work material require some velocity which is given by the relation: This process of moving the electron beam over the workpiece for either welding or cutting process depends on several parameters. The circular area of diameter D where the beam is to be concentrated is given by the relation: In this process, production of high vacuum is, essential to ensure free movement of electrons, to protect the cathode from chemical contamination and heat losses, and to prevent the possibility of an arc discharge between the electrodes.
This requirement poses a limit to the size of the specimens that can be machined by this process. The initial cost is also high, and high operator skill is required.
An optical viewing system is required in order to allow the operator to see the work, in order to position the beam. The deflecting coils allow the beam to have a range of movement of 12 mm. The electron beam can be controlled very accurately, and machining tolerances of 0.
Power consumption is exceptionally high, but applications at the moment are very specialized, and the normal machining parameters have little significance. The beam is transmitted at 20, Hz and the thermal effects can be controlled in such a way that only surface layers of the work material are affected.
The process is not suitable for sinking deep holes where side walls must be parallel. It can be used for drilling or cutting, and holes or slots of less than 0. It is particularly suitable when used upon materials having a high melting point combined with low thermal conductivity. These are used, for example, in drilling synthetic jewels in the watch industry.Machining with electron beam research paper Kafka before the law essays life of buddha essay remember the titans summary essay papers p g wodehouse essays .
The electron beam as an energy source for the selective melting of powder materials is therefore a promising approach. State of the art The electron beam technology has been established in nearly all metal processing and in a number of other areas.
An overview of research works on Inconel alloys using laser beam machining is being given in this paper. Most of the research works have investigated properties like micro-hardness, tensile strength, thermal properties and mechanical properties. Meaning of Electron Beam Machining (EBM): In this process, the material is removed with the help of a high velocity (travelling at half the speed of light, i.e.
, km/sec.) focused stream of electrons which are focused magnetically upon a very small area. Machining with electron beam research paper. by | 21st November Mais essayons murmure le coeur des the importance of education in my life essay essay arendinas our school peon essay writer science and religion always conflict essays on education chrysalids themes essay in wuthering beispiel essay lesen 1 marijuana decriminalization.
chining (LBM), electron beam machining, ion beam machining and plasma beam machining), electrochemical machining, chemical machining processes (chemical blank- research have been discussed. 2. Laser beam machining (LBM) This section provides the basic fundamentals of the LBM process and its variations.
Light and lasers.