1. Introducere 1 pag (ce se stie, ce nu se stie, ce vreau sa fac)2. Obiective 1 pag 3. Metoda de lucru (metode soft, metode experimentale echipament + material)4. Prezentare echipament 1, 2 pag (schema + linii de indicatie)+principiu de lucru (soft daca se

foloseste)5. Performantele procesului si comparatii cu metode asemanatoare, precizie dimensionala rugozitate

costuri, timpi - 2 pag max6. Rezultate asteptate (expected results and deliverable)7. Concluzii 8. Bibliografie

Introduction

In wire EDM a very thin wire serves as the electrode. Special brass wires are typically used; the wire is slowly fed through the material and the electrical discharges actually cut the work piece. Wire EDM is usually performed in a bath of water.

Wire EDM cutting, also known as electrical discharge machining, is a process that uses an electrically energized thin wire to slice through metal. Wire EDM cutting uses rapid, controlled, repetitive spark discharges from the wire to the work piece, thereby eroding the metal away. The work piece must be electrically conductive.

Wire EDM cutting can provide high dimensional accuracy for close fitting parts. The process can make sharp inside corners.

Wire EDM can cut most any simple or complex 2D shape including cutouts and thin walls, intricate openings and sharp inside corners. Examples of a few types of parts that can be cut by wire EDM include:

Custom gears Custom robot parts Custom jewelry Punch and die tooling Stripper plates Mold components etc.

If someone was to observe the wire EDM process under a microscope, he would discover that the wire itself does not actually touch the metal to be cut; the electrical discharges actually remove small amounts of material and allow the wire to be moved through the workpiece. The path of the wire is typically controlled by a computer, which allows extremely complex shapes to be produced.

Perhaps the best way to explain wire EDM is to use an analogy. Imagine a thin metal wire stretched between two hands, slid though a block of cheese, cutting any shape desired. The positions of the hands can be alterred on either side of the cheese to define complex and curved shapes. Wire EDM works in a similar fashion, except electrical discharge machining can handle some of the hardest materials used in industry. Also note that, in dragging a wire through cheese, the wire is actually displacing the cheese as it cuts, but in EDM, a thin kerf is created by removing tiny particles of metal.

Electrical discharge machining is frequently used to make dies and molds. It has recently become a standard method of producing prototypes and some production parts, particularly in low volume applications.

Objectives

The main purpose of this paper is to study the precision and performances obtained in case of EDM Wire cutting. To do this, we have to know some of the parameters who influent the machinability and surface quality of the work piece.

Some of them are:1.electromagnetic force present in wire,2.the dynamics fluid motions of dielectric and dielectric type,3.power supply generator,4.effect of direct current and pulse,5. the machining parameters on surface roughness,6.the electrical conductivity of dielectric fluid,7.the type and grain size of the electro-conductive phase,

1. Clarifies the mechanism of how electromagnetic force applied to the wire electrode in wire

electrical discharge machining (wire-EDM) is generated. This electromagnetic force is caused not only by

DC component but also by AC components of the discharge current supplied to the wire.

2. That means to investigate the fluid flowin the kerf and better jet flushing conditions of working

fluid from the nozzles. The flow field and the debris motion in the kerf were analyzed by computational

fluid dynamics (CFD) simulation, comparing with the observation by high-speed video camera.

3. The power supply can provide high-frequency and very low energy pulses by using transistor-

controlled circuitry. By means of the power supply, the relationship between generator parameters and

peak current were experimentally investigated.

5. Surface roughness is significant to the finish cut of wire electrical discharge machining

(WEDM). This describes the influence of the machining parameters (including pulse duration, discharge

current, sustained pulse time, pulse interval time, polarity effect, material and dielectric) on surface

roughness.

6. The dielectric plays an important role as the working fluid. During machining, the melted

material by heat is dispersed into dielectric. The presence of minute metal particles (gap debris)

contaminates dielectric fluid. It affects the material removal rate and properties of the machined surface

because it exists in the spark gap between work and electrode.

7. It is shown that a variation in grain size of the second phase material significantly influences the

EDM performance, which can be largely related to the microstructure and the properties of the developed

material.

Working method used

This research on accuracy and cutting performance obtained is usually based on previous case

studies that have brought some improvements. Analyzing the results obtained so far can make a

comparison between what was intended to achieve and what must be achieved.

Software methods may be used to determine processing times and any errors that may occur during

the cutting process. In this paper I will try to establish the main problems that can appear in time of

cutting process and to find some solution to reduce or to improve the quality of machined surfaces.

In this case are too many factors that influence the performance and cutting precision, but if we can

adjust some of them, the results will start to come and after them interpretation will take some conclusion

that will helps us to do some changes in some directions.

The equipment

Dielectric filtering system