WHAT IS ELECTRO DISCHARGE MACHINING PROCESS AND IT'S WORKING PRINCIPLES ?
EDM
Electro discharge machining process is an electro thermal non traditional machining process, in which electrical energy is used to generate spark and occur material removal due to electric spark. EDM process is also called as spark erossion machining process where the metal is removed by the erossion of repeated path . It is high voltage and low current process . EDM is mainly used to machine difficult to machining the material and high strength temperature resistante alloy. EDM used to machining difficult geometry in small batches .
A high voltage is applied on EDM , a potential difference is applied between the tool and the workpiece . Here both the tool and workpiece are electrical conductor . The tool and workpiece are immersed in a dielectric medium . A small gap is maintained between the tool and workpiece , depending upon applied voltage . An electronic field would extablished between the tool and workpiece . Generally the tool is connected to the negative terminal and workpiece is connected to the positive terminal of the generator. If the work function or binding energy of electron is less, electron is called cold emission of electron is called cold emission. The cold emitted electron are accelerate towards the workpiece through dielectric medium. The cyclic process would increase the concentration of electrons in the dielectric medium between the tool and the workpiece at the spark gap .Thus the large of electron will flow from the tool to the workpiece and ions from the workpiece to the tool . The electrical energy is dissipated as that thermal energy of the spark. High speed of electron impinges on the workpiece and ions to the tools , the kinetic energy of electron impact on the surface of the workpiece and converted in to thermal energy ( Heat flux) . Such head flux rises the temperature and leads the metal to remove (10,000•c ) .
Electro discharge machining process is an electro thermal non traditional machining process, in which electrical energy is used to generate spark and occur material removal due to electric spark. EDM process is also called as spark erossion machining process where the metal is removed by the erossion of repeated path . It is high voltage and low current process . EDM is mainly used to machine difficult to machining the material and high strength temperature resistante alloy. EDM used to machining difficult geometry in small batches .
WORKING PRINCIPLES.
A high voltage is applied on EDM , a potential difference is applied between the tool and the workpiece . Here both the tool and workpiece are electrical conductor . The tool and workpiece are immersed in a dielectric medium . A small gap is maintained between the tool and workpiece , depending upon applied voltage . An electronic field would extablished between the tool and workpiece . Generally the tool is connected to the negative terminal and workpiece is connected to the positive terminal of the generator. If the work function or binding energy of electron is less, electron is called cold emission of electron is called cold emission. The cold emitted electron are accelerate towards the workpiece through dielectric medium. The cyclic process would increase the concentration of electrons in the dielectric medium between the tool and the workpiece at the spark gap .Thus the large of electron will flow from the tool to the workpiece and ions from the workpiece to the tool . The electrical energy is dissipated as that thermal energy of the spark. High speed of electron impinges on the workpiece and ions to the tools , the kinetic energy of electron impact on the surface of the workpiece and converted in to thermal energy ( Heat flux) . Such head flux rises the temperature and leads the metal to remove (10,000•c ) .
Advantages:-
1:- +- 0.005mm tolerance can be achieved in EDM.
2:- Material hardness doesn't effect in this process.
3:- Cutting complex shape will be done in EDM.
4:- EDM is indirect contact and no forces is required for the machining.
Disadvantages :-
1:- EDM process only able to machining conductive material.
2:- more expensive process than conventional machining .
0 comments:
Post a Comment
Please don't enter any spam link in the comment box.