E EM D EGEEED ME EDM Graphite · 6 EDM-200® graphite EDM-200 is an isotropic Superfine particle graphite providing good strength, electrodes surface finish, and wear resistance.

SPECIALTY CHEMICALS AND ENGINEERED MATERIALS

EDM GraphiteSelection guide

2

Aerospace Applications

• Blades

• Vanes

• SealSlots

Consumer Applications

• CapsandClosures

• PlasticInjection

• ElectricalConnectors

Automotive Applications

• Speakers

• Lenses

• PowerDistribution

Medical Applications

• SurgicalFasteners

• DentalImplants

• OrthopedicJoints

7.92

mm

(0.3

12”)

APPLICATIONS—OurEDMelectrodematerialsofferthebestbalanceofmetalremovalrates,lowelectrodewear,andexcellent

totalcostofownership.EachEDMgraphitegradeprovidesconsistentperformancefromblocktoblock,

yeartoyear,andhasbeentailoredforaspecificrangeofelectrodeapplicationswithbenchmarkedperfor-

mancecharacteristics.

3

KEY FACTORS OF ELECTRODE SELECTION—EDMhastakenitsplaceasaproven,precision

technology,chosenforwhatitcando,ratherthan

whatconventionalmachiningcannotdo.EDM

machinetechnologyhasspawnedaworldofnew

applicationswhereinincreasedimportanceis

placedonthegraphiteelectrodematerialutilized.

Whiletherearemanymethodsusedtodetermine

therightmaterialforajob,webelievetherearefive

factorsthatmeanthedifferencebetweensuccess

andfailure,profitandloss.

Metal Removal Rate (MRR)

Metalremovalrateisusuallyexpressedascubic

millimetersperhour(mm3/hr)orcubicinchesper

hour(in3/hr),butinfactcouldjustasrealisticallybe

expressedas$/hr.AchievinganefficientMRRisnot

simplyamatteroftherightmachinesettings.Italso

involvesdirectenergydissipatedintheEDMprocess.

Graphiteisgenerallymuchmoreefficientthan

metallicelectrodes,howevermetalremovalrates

varywidelybetweengraphitetypes.Withtheproper

electrodematerial/workmetal/applicationcombina-

tion,MRRcanbemaximized.

Wear Resistance (WR)

Therearefourtypesofwear:volumetric,corner,end,

andside.Ofthefour,webelievethatcornerwearis

themostimportantsincethecontoursofthefinalcut

aredeterminedbytheelectrode’sabilitytoresistthe

erosionofitscornersandedges.Itfollowsthatifan

electrodecansuccessfullyresisterosionatitsmost

vulnerablepoints,thenoverallwearwillbeminimized,

andmaximumelectrodelifeachieved.Electrode

erosioncannotbeprevented,butitcanbeminimized

bychoosingtheproperelectrodematerial/workmetal

combinationandmachiningattheoptimumsettings.

Theabilityofanelectrodetoproduceandmaintain

detailisdirectlyrelatedtoitsresistancetowearand

itsmachinability.Minimizingcornerwearrequires

choosinganelectrodematerialthatcombineshigh

strengthwithhightemperatureresistance.

Surface Finish (SF)

Finesurfacefinishisobtainedbyacombinationof

theproperelectrodematerial,goodflushingcondi-

tions,andtheproperpowersupplysettings.High

frequency,lowpower,andorbitingproducethe

bestfinish,astheseconditionsproducesmaller,less

definedcratersintheworkmetal.Thefinalsurface

finishwillbeamirrorimageoftheelectrode’ssurface,

soAngstrofineandUltrafineparticle,highstrength

graphitesarethebestchoicesforfinishingelectrodes.

Machinability

Anymachinistwhohasevermachinedgraphiteis

awarethatgraphitecutsveryeasily.Simplybeingeasy

tomachinedoesnotnecessarilymakeamaterialthe

bestchoiceforanelectrode.Itmustalsobestrongto

resistdamagefromhandlingandfromtheEDMprocess

itself.Strengthandsmallparticlesizeareimportant

sothatminimumradiiandclosetolerancesmaybe

achieved.Materialhardnessisalsoafactoringraphite

machinability.Harderelectrodematerialswillbemore

pronetochippingduringthemachiningprocess.

Material Cost

Electrodematerialcostgenerallyrepresentsonlya

smallpartofthetotalEDMjobcost.Whatistoooften

overlooked,however,isthatelectrodematerialcost

consideredoutsidethetotaljobcostiscompletely

meaningless.

Fabricationtime,cuttingtime,labor,andelectrodewear

alldependontheelectrodematerialmorethanon

anyotherfactor.Thusitiscriticalthatyouknowthe

propertiesandperformancecharacteristicsofthe

availableelectrodematerialsastheyaffectthework

metalsyouaremachining.Onlywiththisdataisit

possibletomakeacost/performanceanalysisto

determinethetruecostofanEDMjob.

4

EDM-AF5®graphite

EDM-AF5isthepremier

graphiteelectrode

materialavailableonthe

markettodaywithan

averageparticlesizeof

lessthanonemicron.

Thisparticlestructure

hassuperiorstrength,

providesforfinesurfacefinish(7μinRa),and

givesexcellentmetalremovalrateandhigh

resistancetowear.

TypicalValue

Average particle size:

<1 µm

Flexural strength:

1,019 kg/cm2 (14,500 psi)

Compressive strength:

1,554 kg/cm2 (22,100 psi)

Hardness: 83 Shore

Electrical resistivity:

21.6 µΩm (850 µΩin)

Applications

• Finedetailedelectrodesforengraving

• Hardtomachinedetail

• Delicateandfragileelectrodes

• Varioustypethreadingelectrodes

• Jobsrequiringfinesurfacefinishes

• Intricatemoldsanddies

GRAPHITE GRADES—

EDM-C3®graphite

EDM-C3isahigh-quality

graphiteinfiltratedwith

copper,recommended

wherespeed,wear,

andsurfacefinishare

important.Unequalled

forfragileelectrodes,

manyEDMerschoose

thisgradetocompensateforoperator

inexperienceorwherepoorflushingcondi-

tionsexists.

TypicalValue


<5 µm

Flexural strength:

1,427 kg/cm2 (20,300 psi)


1,993 kg/cm2 (28,350 psi)

Hardness: 66 Shore


3.2 µΩm (127 µΩin)

Applications

• Finedetailedelectrodeswherestrengthiscritical

• Threadingelectrodes

• Aerospaceapplications

• Plasticinjectionmolds

• Machiningofcarbide

• Smallholedrilling

Copper Ultrafine

Our 5 micron EDM material Competitor’s 5 micron material

Angstrofine Graphite

5

EDM-3®graphite

EDM-3isanisotropic

Ultrafinegraingraphite

thatoffershighstrength

withoutstandingwearand

finesurfacefinishcharac-

teristicseasilymachined

tothicknessesof0.1mm

orless.

TypicalValue


<5 µm

Flexural strength:

935 kg/cm2 (13,300 psi)


1,273 kg/cm2 (18,100 psi)

Hardness: 73 Shore


15.6 µΩm (615 µΩin)

Applications

• EDMingoffinedetailedelectrodes

• Punchanddiesets


• Threadingelectrodes

• Useinaerospacemetalcutting

EDM-2®graphite

EDM-2isanisotropic

Ultrafinegraingraphite

withhighstrengthand

goodwearcharacteris-

tics.Recommendedfor

useondetailedelec-

trodes,wherespeed,fine

finish,andresistanceto

weararedesired.

TypicalValue


<5 microns

Flexural strength:

787 kg/cm2 (11,200 psi)


1,188 kg/cm2 (16,900 psi)

Hardness: 71 Shore


16.0 µΩm (620 µΩin)

Applications

• ICMolds

• Aerospaceapplications

• Fine-detailedelectrodes

• Minimum-taper-cavities

• Blindcavitywork

Ultrafine Graphite

EDM-4®graphite

EDM-4isthepremier

offeringintheUltrafine

grainclassification.This

highlyisotropicgrade

combinesextraordinary

strengthwithmoderate

hardness,yieldingsuper-

iorelectrodefabrication

characteristics.EDM-4hassuperiorEDM

performancecharacteristicsformetalremoval

rates,wearandsurfacefinish.

TypicalValue


<4 µm

Flexural strength:

1,230 kg/cm2 (17,500 psi)


1,511 kg/cm2 (21,500 psi)

Hardness: 76 Shore


12.7 µΩm (500 µΩin)

Applications

• EDMingoffinedetailedelectrodesrequiringexcellentsurfacefinishes

• Wirecutelectrodes


Ultrafine Graphite

6

EDM-200®graphite

EDM-200isanisotropic

Superfineparticlegraphite

providinggoodstrength,

surfacefinish,andwear

resistance.Moderately

priced,EDM-200graphite

providesexcellentrepeat-

abilityfromelectrodeto

electrodeandfromjob

tojob.

EDM-C200®graphite

EDM-C200isaSuperfine

graphiteinfiltratedwith

copperthatoffersexcel-

lentmetalremovalrates

andgoodwearresistance.

EDM-C200graphite

improvescuttingstability

inpoorflushingcondi-

tions,andisanexcellentmaterialforcutting

aerospacealloys.

TypicalValue


10 µm

Flexural strength:

635 kg/cm2 (9,000 psi)


1,075 kg/cm2 (15,500 psi)

Hardness: 68 Shore


14.7 µΩm (580 µΩin)

TypicalValue


10 µm

Flexural strength:

851 kg/cm2 (12,100 psi)


1,631 kg/cm2 (23,200 psi)

Hardness: 62 Shore


2.9 µΩm (114 µΩin)

Applications

• Structuralribs

• Roughingorfinishingelectrodes

• Largefeaturedmold

• Highstrengthlargeelectrodes

Applications

• EDMingoffinedetailedelectrodesrequiringexcellentsurfacefinishes

• Wirecutelectrodes


Superfine Graphite

Copper Superfine

EDM-1®graphite

EDM-1graphiteisour

lowestpricedUltrafine

graingraphite.Inaddition

toprovidinggoodwear

resistance,speed,and

finish,lowerelectrode

fabricationcostsare

possiblewhenlarger

electrodesarerequired.

TypicalValue


<5 µm

Flexural strength:

682 kg/cm2 (9,700 psi)


988 kg/cm2 (14,200 psi)

Hardness: 69 Shore


19.3 µΩm (760 µΩin)

Applications

• Fabricatingelectrodeswithgooddetail

• Lowwearelectrodes

• Highdetailroughingelectrodes

• Moldsanddies

7

TECHNICAL ARTICLES—AllarticlescanbeaccessedbyscanningtheQRcode

orvisitingusatpoco.com.

Total Cost of Ownership

TheTotalCostofOwnership

(TCO)modelandanalysis

arecommonlyusedtomake

decisionswhenpurchasing

newequipment,butcan

alsobeappliedtothemajor

elementsassociatedwiththe

operationofthesinkerEDM

equipment,suchasgraphiteelectrodematerials.When

TCOprincipalsareappliedtothesemajorelements,

thevaluepropositionandproductivityofthese

elementsstarttoimpactprofitabilityofowningand

operatingtheequipment.

Thisarticleprovidesinsightintothekey

aspectsofapplyingtheTotalCostof

OwnershipModeltoyourelectrode

materialselectionprocess,andusing

thismethodtomaximizetheefficiency

ofyourEDMprocess.

Dealing with Graphite Dust

Dust,acommonhouseholdwordthat

canbedefinedasafinelypowdered

substanceofvariousmattersoften

suspendedintheair.Thisarticlereviews

thecharacteristicsofgraphitedustand

answersoften-askedquestionsin

dealingwithit.

Making EDM Profitable

Thisarticlereviewsthefactorstocon-

siderwhenworkingwithanexotic

workmetalapplication,andareal-world

exampleofhowelectrodematerial

selectionandEDMparameterscan

impactthebottomline.

Electrode Effect on Quality EDM Finish

Thisarticlediscussestheeconomic

impacttheelectrodematerialhason

producingfinesurfacefinisheseven

withthenewerEDMgeneratortechnol-

ogy.Toaccessmoreinformationabout

howthequalityofyourelectrodematerialcanimpact

yourworkpiecefinish,scantheQRcodetoaccess

thefullarticle.

EDM Effect on Surface Integrity

Learnaboutthealteredmetallayers

createdduringtheEDMprocess,and

howtheEDMprocessparameters

canimpacttheworkpiecefinishand

surfaceintegrity.

Sometimes Graphite Isn’t Enough

Anexplanationofhowthecorrect

machineparameterscanimprove

yourEDMprocesswhendealing

withnon-standardmaterials,such

asberylliumcopper,titanium,and

tungstencarbide.

Graphite vs. Copper

Viewatruecostcomparisonoftime

andmaterialbetweencopperand

graphiteelectrodes,andexaminethe

differencesbetweeneachoftheEDM

keyperformanceindicators.Scanthe

QRcodetoreadthefullarticleandto

learnmoreaboutcopperversusgraphite.

EDM Graphite Buyer’s Guide

Unlessyouhavemoneytoburn,time

tospare,andagreatmoldrepairteam,

neverbuyEDMgraphitedescribedas

“equivalentto”or“asgoodas.”Learn

tipsonhowtoassureyouaregetting

whatyouneedwhenitcomesto

sourcinggraphite.

Apply

Justify

Compare Data

Benchmark

Calculate Results

Measure Process

Simulate Procedures

http://www.poco.com

FOR MORE INFORMATION

Pleasecallyourlocaldistributortolearnwhatourpremiumgraphitesolutionscandoforyou.Visitpoco.entegris.com/distributorsforthelocationnearestyou.

TERMS AND CONDITIONS OF SALE

AllpurchasesaresubjecttoPocoGraphite’sTermsandConditionsofSale.Toviewandprintthisinformation,visitpoco.entegris.com/terms-and-conditions.

www.poco.entegris.com

Entegris®andtheEntegrisRingsDesign®aretrademarksofEntegris,Inc.,andPOCO®andotherproductnamesaretrademarksofPocoGraphite,Inc.,aslistedonentegris.com/trademarks.Allthird-partyproductnames,logos,andcompanynamesaretrademarksorregisteredtrademarksoftheirrespectiveowners.Useofthemdoesnotimplyanyaffiliation,sponsorship,orendorsementbythetrademarkowner.

©2010-2020Entegris,Inc.|Allrightsreserved.|PrintedintheUSA|6207-10116TAN-0420

300 Old Greenwood RoadDecatur, Texas 76234 USA

Tel +1 940 627 2121Fax +1 940 393 8366

Customer Service

TECHNICAL ASSISTANCE—Ifyouhaveaquestionconcerningelectrodemateri-

als(oursoranyoneelses),calltheEDMexperts.Our

EDMtechnicalservicepersonnelhavemanyyears

ofpracticalEDMexperienceandcanhelpyou

withdesign,machining,operatingparameters,or

practicallyanysituationinvolvingelectrodeman-

agementtechniques.

• Gradeverification

• Productionproblems

• Applicationsspecialists

INDUSTRY-LEADING EDM TRAINING—WeofferanEDMtechnicaltrainingprogramto

helpEDMersimprovetheirperformance.Thisisa

no-charge,three-daytrainingsessionthatincludes

classroomandlaboratoryactivities,andprovidesa

betterunderstandingofhowtocontroltheEDM

processtoachievepredictableresults.Thisis

practicalinformationthattheattendeecanput

touseontheshopfloor.

• EDMbasics

• EDMsinkertechnology

• Propertiesandcharacteristicsofgraphite

EDM TECHNICAL MANUAL—OurEDM Technical Manualisnowavailableonlineat

www.edmtechman.comorasanappforyouriOSor

Androiddevice.

iOS Device Android Device

http://www.poco.com

http://www.poco.com

https://www.entegris.com/content/en/home/about-us/legal-trademark-notices.html

E EM D EGEEED ME EDM Graphite · 6 EDM-200® graphite EDM-200 is an isotropic Superfine particle graphite providing good strength, electrodes surface finish, and wear resistance.

Documents