De burring using edm

Presented byMr. Amol Jalinder Torane

TE (Mechanical)

Under the Guidance ofProf. Parag Marathe

Department of Mechanical Engineering

Dr. D. Y. Patil SOE Lohegaon, Pune – 412105.For A. Y. 2016-17

Contents of SeminarIntroductionLiterature reviewBasic principle of EDMConstruction and workingTypes of EDM processBurr formation in micro machiningDe-burring using EDMDi-electric fluidMethods of fluid applicationQuantification of resultsAdvantages/ Disadvantages / Applications

Dr. D. Y. Patil School of Engineering,Lohegaon, Pune. 2

Introduction Most extensively used non-

conventional, controlled metal removal process that is used to remove metal by means of electrical spark erosion.

The first EDM system was developed by Lazarenko in 1943.

The metal removal process is performed by applying a pulsating (on/off) electrical charge of high frequency current through the electrode to the work piece immersed in dielectric medium.

3Dr. D. Y. Patil School of Engineering,Lohegaon, Pune.

Dr. D. Y. Patil School of Engineering Lohegaon ,Pune.

Sr. No.

Title of PaperType of

document & Published Year

Topic /Conclusion of Paper Retrieval for My Seminar

1 Evolution of Electrical Discharge Machining: A Review.

International Journal of Science and Research (2015).

The Material Removal Rate by using EDM can be achieve as high as 5162 mm^3/min.

2 Electrode Wear Protection Mechanism in micro-EDM.

Journal of Materials Processing Technology (2015).

A Diamond like amorphous carbon layer embedded with the micro sized metallic debris is deposited on the erosion front of the electrode.

3 Super-Finished Surfaces using micro-EDM. ISEM 2013

A Stray Capacitance Sinking EDM machine offers the Capability to achieve Super-Finished Surfaces.

4

Optimization of Machining Parameters in EDM Process using cast and Sintered Electrode.

ICMPC 2014

The cast copper and sintered powder metallurgy copper have been considered as tool electrodes to machine the fore said workpieces.

5

Accuracy Improvement Through the use of EdM Machining Instead of Conventional Machining.

Journal of Materials Processing Technology (2016)

Instead of using conventional process we shall use non- conventional process such as EDM for getting higher MMR, along with higher accuracy in terms of quality of the work.

Literature Review

4

Basic principle of EDMWork piece and tool are

submerged in a dielectric fluidWork piece and tool is

separated by small gap called spark gap

Gap is kept so the spark can take place and material can be removed from the work piece

The dielectric is replaced after sometime with the help of pump and filter


Construction and Working


EDM – Working Principle


Types of electric discharge machining

Ram type EDM (Die sinker EDM)

Wire type EDMSmall hole EDM


1. Ram type electric discharge machiningPre shaped electrode is

used to produce blind cavities in the w/p.

Reverse shape of the electrode is eroded into the solid w/p.

Dielectric oil is used for this process.


2. Wire type electric discharge machiningContinuous travelling vertical wire is

used which is under tension.Wire diameter varies from 0.05mm-

0.33mm.Hundred thousand sparks occur in 1

second.Deionized water is used as dielectric.Flushing or submerged type

machines are available.


3. Small hole electrical discharge machining Tubular electrodes are

rotated while machining (aids in flushing and uniform electrode wear).

Wire diameters ranging from 0.152mm to 6mm used.

Depth to diameter ratio up to 100:1.

Wire diameters ranging from 0.152mm to 6mm


“De-Burring using Electric Discharge Machining”


Burr formation in machining


A burr is a raised edge or small piece of material remaining attached to a workpiece after a modification process.

It is usually an unwanted piece of material and is removed with a deburring tool in a process called 'deburring'. Burrs are most commonly created by machining operations, such as grinding, drilling, milling, engraving or turning. It may be present in the form of a fine wire on the edge of a freshly sharpened tool or as a raised portion of a surface

Burr formation in machining


Fig. 1. Metal burr extending beyond the edge of the cut piece, view on the

cut face (top) and from the bottom

Burrs generated after a micro slot machining process.

Definition of burr Geometry


The burr geometry on a miniature part can be characterized by the height, width, radius, and length of the burr.

the burr information is useful for determining the machining condition and tool path planning

The burr height, influences the determination of the vertical offset of the tool from the top plane, is the difference between the top plane and the highest point of the burr.

Deburring using electro discharge machiningWhen a cylindrical EDM tool approaches

a workpiece edge with burrs, the burr on the top plane is closest to the tool. Therefore, a plasma channel is generated between the tool and the burr.

The heat energy with high intensity and short duration is concentrated in the area of the burr the burr is likely to be removed first when the distance between the tool and the top plane of the workpiece is adjusted appropriately.


Dielectric Fluids

It acts as an insulator.Acts as a coolant medium and reduces the extremely high temp. in the arc gap. It acts as a Flushing medium.


Basic requirements are:Low viscosityAbsence of toxic vapoursChemical neutralityLow cost.

Methods of fluid application


Pressure

1. Down Through the Electrode

Pressure

2. Up Through the Workpiece

Suction

3. Vacuum Flow

Vibration

4. Vibration

Deburring process


Fig. shows the material removal regions of a three-step deburring process using micro-EDM: rough deburring,

finish deburring, and edge finishing.

Quantification of Results


Fig. shows the Comparison of height profiles between rough-deburred and finish-deburred edges: (a) aluminium alloy, (b) copper and

(c) stainless steel.

Advantages of electric discharge machining Any electrically conductive material can be

cut. Hardened and exotic materials can be

machined with ease. Complex sections can be produced

accurately, faster and at lower rates. Burr free operation. Fragile and thin sections like webs or fins

can be easily machined without deformation of the part.

No cutting forces induced. Superior finish, accuracy and repeatability. Minimum operator intervention.


Turbine blades

Intricately detailed automobile part

Limitations of electric discharge machiningNot suitable for non-conductors.Low metal removal process as compared to chip machining.Matte type appearance is obtained and further polishing is

required if gloss finish is needed.Rapid electrode wear makes the process more costly.Smoke produced is harmful to lungs and eyes.Chances of flash fire in dielectric fluid (oil).Specific power consumption is high.


Applications of electric discharge machining

Die making.Aerospace components.Form tools.Stamping tools.Medical and dental

instrumentation.Prototype parts.Micro pins, micro-nozzles,

and micro cavities.Dr. D. Y. Patil School of Engineering,Lohegaon, Pune. 23

ReferencesPapers from Journals:

Young Hun Jeong, Byung HanYoo, Han Ul Lee, Byung-Kwon Min, Dong-Woo Cho, Sang Jo Lee, “DE-burring micro-features using micro-EDM’ Journal of Materials Processing Technology

S. Ravinder Reddy, Anil Kumar N, K. Prashanth Reddy, G Sudhir Kumar Yadav, DR. Dipak Ranjan Jana, “Accuracy improvement through the use of electronic discharge machining instead of conventional machining”, International Education & Reserch Journal. E-ISSN No.- 2454-9916, Volume 2, Isue 3, March 2016.

U. Maradia, M. Boccadoro, J. Stirnimann, F. Kuster, K. Wegener, “Electrode wear protection mechanism in meso-micro-EDM”, Journal of Material Processing Technology223 (2015) 22-33, Elsevier.

Vishal Pathania, Narinder Singh Jassal, “Brif Chronological Study of the Evolution of Electrical Discharge Machining- A Review”, International Journal of Science and Research, 2319-7064, Index Copernius Value (2015).

24Dr. D. Y. Patil School of Engineering,Lohegaon, Pune.

Questions


THANK YOU !
