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NONTRADITIONALMACHINING

Compiled by:

Norliana Mohd Abbas

Sources:

1. Manufacturing Engineering & Technology 5th Edition, Serope Kalpakjian,

Steven Schmid, rentice !all, "##$

". %undamental of Modern Manufacturing' Material, rocee andSytem, Mikell . (roover, )ohn *iley & Son +ia-, "##

/. M0M !andout "##

2. dvanced Machining rocee, 3ontraditional and !y4rid Machining

rocee, !aan El!ofy, Mc(ra6 !ill, "##5

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Conen

1. Introduction

2. Mechanical Energy Processes

3. Chemical & Electrochemical Machining

Processes

4. Thermal Energy Processes

5. Alication Considerations

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Nonradiional !rocesses De"ined

A grou o! rocesses that remo"e e#cess material

$y "arious techni%ues in"ol"ing mechanical

thermal electrical or chemical energy 'or

com$inations o! these energies(

They do not use a shar cutting tool in the

con"entional sense

)e"eloed since *orld *ar II in resonse to

ne+ and unusual machining re%uirements that

could not $e satis!ied $y con"entional methods

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Imporance o" Nonradiional !rocesses

,eed to machine ne+ly de"eloed metals and

non metals +ith secial roerties that ma-e

them di!!icult or imossi$le to machine $y

con"entional methods

,eed !or unusual andor comle# art

geometries that cannot readily $e

accomlished $y con"entional machining

,eed to a"oid sur!ace damage that o!ten

accomanies con"entional machining

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Classi"icaion o" Nonradiional !rocesses

Mechanical tyical !orm o! mechanical action is erosion o!

+or- material $y a high "elocity stream o! a$rasi"es or !luid

'or $oth(

Electrical electrochemical energy to remo"e material 're"erse

o! electrolating(

Thermal / thermal energy usually alied to small ortion o!

+or- sur!ace causing that ortion to $e !used andor

"aori0ed

Chemical / chemical etchants selecti"ely remo"e material !rom

ortions o! +or-art +hile other ortions are rotected $y a

mas-

Hassan El-Hofy list only 3 major areas of NTM: Mechanical, thermal and

chemical & electro-chemical

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Mechanical #ner$y !rocesses

1. Ultrasonic machining (USM)

2. Water jet machining (WJM)

3. Abrasive water jet cutting (AWJM)

. Abrasive jet machining (AJM)

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%lrasonic Machinin$ &%SM'

A$rasi"es contained in a slurry are dri"en at high "elocity

against +or- $y a tool "i$rating at lo+ amlitude and

high !re%uency

Tool oscillation is erendicular to +or- sur!ace

A$rasi"es accomlish material remo"al Tool is !ed slo+ly into +or-

hae o! tool is !ormed into art

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Ultrasonic Machining (USM)

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%SM Applicaions

ard $rittle +or- materials such as ceramics glass and

car$ides

Also success!ul on certain metals such as stainless

steel and titanium

haes include nonround holes holes along a cur"eda#is

Coining oerations6 attern on tool is imarted to a

!lat +or- sur!ace

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7ses high ressure high "elocity stream o! +aterdirected at +or- sur!ace !or cutting

Water Jet Cutting (WJC)

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()C Applicaions

7sually automated $y C,C or industrial ro$ots to

maniulate no00le along desired tra8ectory

7sed to cut narro+ slits in !lat stoc- such as lastic

te#tiles comosites !loor tile caret leather and

card$oard

,ot suita$le !or $rittle materials 'e.g. glass(

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()C Ad*ana$es

,o crushing or $urning o! +or- sur!ace

Minimum material loss

,o en"ironmental ollution

Ease o! automation

()C Disd*ana$es

ourly rates are relati"ely high

,ot suita$le !or mass roduction $ecause o! high

maintenance re%uirements

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Abrasi*e (aer )e Cuin$ &A()C'

*hen *9C is used on metals a$rasi"e articles must $e

added to 8et stream usually

Additional rocess arameters: a$rasi"e tye grit si0e

and !lo+ rate

A$rasi"es: aluminum o#ide silicon dio#ide and

garnet 'a silicate mineral(

;rit si0es range $et+een

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igh "elocity stream o! gas containing smalla$rasi"e articles

Abrasive Jet Machining (AJM)

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A)M Applicaion Noes

7sually er!ormed manually $y oerator +ho directs

no00le

,ormally used as a !inishing rocess rather than cutting

rocess

Alications: de$urring trimming and de!lashing

cleaning and olishing

*or- materials: thin !lat stoc- o! hard $rittle materials

'e.g. glass silicon mica ceramics(

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Chemical + #lecrochemical Machinin$

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#lecrochemical Machinin$ !rocesses

Electrical energy used in com$ination +ith chemical

reactions to remo"e material

>e"erse o! electrolating

*or- material must $e a conductor

An electrolyte acts as current carrier and the high rate o!electrolyte mo"ement in the tool+or-iece ga 'tyically

=.1 to =.< mm( +ashes metal ions a+ay !rom the

+or-iece 'anode( $e!ore they ha"e a chance to late

onto the tool 'cathode(.

Processes: Electrochemical machining 'ECM(

Electrochemical de$urring 'EC)(

Electrochemical grinding 'EC;(

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Material remo"al $y anodic dissolution usingelectrode 'tool( in close ro#imity to +or- $ut

searated $y a raidly !lo+ing electrolyte

Electrochemical Machining (ECM)

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#CM Operaion

Material is delated !rom anode +or-iece 'ositi"e ole(

and transorted to a cathode tool 'negati"e ole( in an

electrolyte $ath

Electrolyte !lo+s raidly $et+een t+o oles to carry o!!

delated material so it does not late onto tool

Electrode materials: Cu $rass or stainless steel

Tool has in"erse shae o! art

Tool si0e and shae must allo+ !or the ga

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#CM Applicaions

)ie sin-ing irregular shaes and contours !or !orging

dies lastic molds and other tools

Multile hole drilling many holes can $e drilled

simultaneously +ith ECM

oles that are not round since rotating drill is not used

in ECM

)e$urring

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Adatation o! ECM to remo"e $urrs or shar corners onholes in metal arts roduced $y con"entional

through hole drilling

Electrochemical Deburring (ECD)

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ecial !orm o! ECM in +hich grinding +heel +ithconducti"e $ond material augments anodic

dissolution o! metal art sur!ace

Electrochemical Grining (ECG)

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Applicaions and Ad*ana$es o" #CG

Alications: harening o! cemented car$ide tools

;rinding o! surgical needles other thin +all

tu$es and !ragile arts

Ad"antages:

)elating resonsi$le !or ?5@ o! metal

remo"al

ecause machining is mostly $y

electrochemical action grinding +heel lasts

much longer

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Chemical Machinin$ &CHM'

Material remo"al through contact +ith a strong chemicaletchant

Processes include:

Chemical milling

Chemical $lan-ing Chemical engra"ing

Photochemical machining

All utili0e the same mechanism o! material remo"al

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Seps in Chemical Machinin$

1. Cleaning to insure uni!orm etching

2. Mas-ing a mas-ant 'resist chemically resistant to

etchant( is alied to ortions o! +or- sur!ace not to $e

etched

3. Etching art is immersed in etchant +hich chemically

attac-s those ortions o! +or- sur!ace that are not

mas-ed

4. )emas-ing mas-ant is remo"ed

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Mas,an in Chemical Machinin$

Materials: neorene oly"inylchloride olyethylene andother olymers

Mas-ing accomlished $y any o! three methods:

Cut and eel

Photograhic resist creen resist

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Cu and !eel Mas,an Mehod

Mas-ant is alied o"er entire art $y diing aintingor sraying

A!ter mas-ant hardens it is cut $y hand using a scri$ing

-ni!e and eeled a+ay in areas o! +or- sur!ace to $e

etched

7sed !or large +or-arts lo+ roduction %uantities and

+here accuracy is not a critical !actor

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!hoo$raphic Resis Mehod

Mas-ing materials contain hotosensiti"e chemicals Mas-ant is alied to +or- sur!ace and e#osed to light

through a negati"e image o! areas to $e etched

These areas are then remo"ed using hotograhicde"eloing techni%ues

>emaining areas are "ulnera$le to etching Alications:

mall arts roduced in high %uantities

Integrated circuits and rinted circuit cards

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Screen Resis Mehod

Mas-ant alied $y sil- screening6 methods

Mas-ant is ainted through a sil- or stainless steel mesh

containing stencil onto sur!ace areas that are not to $e

etched

Alications:

et+een other t+o mas-ing methods

Ba$rication o! rinted circuit $oards

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#chan

Bactors in selection o! etchant:

*or- material

)eth and rate o! material remo"al

ur!ace !inish re%uirements

Etchant must also $e matched +ith the tye o! mas-antto insure that mas-ant material is not chemically

attac-ed

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Maerial Remo*al Rae in CHM

;enerally indicated as enetration rates mmmin'inmin( since rate o! chemical attac- is directed into

sur!ace

Penetration rate is una!!ected $y sur!ace area

Tyical enetration $et+een =.=2= and =.=5= mmmin

'=.=== and =.==2 in.min(

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e%uence o! rocessing stes in chemical milling:

'1( clean ra+ art

'2( aly mas-ant

'3( scri$e cut and eel the mas-ant !rom areas to $e etched

'4( etch

'5( remo"e mas-ant and clean to yield !inished art.

Chemical Milling

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Applicaions o" Chemical Millin$

>emo"e material !rom aircra!t +ing and !uselage anels!or +eight reduction

Alica$le to large arts +here su$stantial amounts o!

metal are remo"ed

Cut and eel mas-ant method is used

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Chemical -lan,in$

7ses chemical erosion to cut "ery thin sheetmetal arts

do+n to =.=25 mm '=.==1 in( thic- andor !or intricate

cutting atterns

Con"entional unch and die does not +or- $ecause

staming !orces damage the thin sheetmetal or tooling

cost is rohi$iti"e or $oth

Mas-ant methods are either hotoresist or screen resist

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Parts made $y chemical $lan-ing 'hoto courtesy o!

uc-$eeMears t. Paul(.

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!hoochemical Machinin$ &!CM'

7ses hotoresist mas-ing method

Alies to chemical $lan-ing and chemical engra"ing

+hen hotograhic resist method is used

7sed e#tensi"ely in the electronics industry to roduce

intricate circuit designs on semiconductor +a!ers

Also used in rinted circuit $oard !a$rication

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Thermal #ner$y !rocesses . O*er*ie/

Dery high local temeratures

Material is remo"ed $y !usion or "aori0ation

Physical and metallurgical damage to the ne+ +or-

sur!ace

In some cases resulting !inish is so oor thatsu$se%uent rocessing is re%uired

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Thermal #ner$y !rocesses

Electric dischargemachining

Electric discharge +irecutting

Electron $eammachining

aser $eam machining

Plasma arc machining

Con"entional thermalcutting rocesses

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#lecric Dischar$e !rocesses

Metal remo"al $y a series o! discrete electrical discharges'sar-s( causing locali0ed temeratures high enough to

melt or "aori0e the metal

Can $e used only on electrically conducting +or-

materials

T+o main rocesses:

1. Electric discharge machining

2. *ire electric discharge machining

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Electric discharge machining 'E)M(: 'a( o"erall setu and '$(close u "ie+ o! ga sho+ing discharge and metal remo"al.

Electric Discharge Machining (EDM)

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#DM Operaion

Fne o! the most +idely used nontraditional rocesses

hae o! !inished +or- sur!ace roduced $y a shae o!

electrode tool

ar-s occur across a small ga $et+een tool and +or-

>e%uires dielectric !luid +hich creates a ath !or eachdischarge as !luid $ecomes ioni0ed in the ga

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(or, Maerials in #DM

*or- materials must $e electrically conducting

ardness and strength o! +or- material are not

!actors in E)M

Material remo"al rate deends on melting oint o!

+or- material

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#DM Applicaions

Tooling !or many mechanical rocesses: molds !orlastic in8ection molding e#trusion dies +ire dra+ing

dies !orging and heading dies and sheetmetal staming

dies

Production arts: delicate arts not rigid enough to

+ithstand con"entional cutting !orces hole drilling

+here hole a#is is at an acute angle to sur!ace and

machining o! hard and e#otic metals

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ecial !orm o! E)M uses small diameter +ire aselectrode to cut a narro+ -er! in +or-

Wire EDM

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Operaion o" (ire #DM

*or- is !ed slo+ly ast +ire along desired cutting athli-e a $andsa+ oeration

C,C used !or motion control

*hile cutting +ire is continuously ad"anced $et+een

suly sool and ta-e u sool to maintain a constant

diameter

)ielectric re%uired using no00les directed at tool +or-

inter!ace or su$merging +or-art

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)e!inition o! -er! and o"ercut in electric discharge +ire

cutting.

Wire EDM

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(ire #DM Applicaions

Ideal !or staming die comonents ince -er! is so narro+ it is o!ten ossi$le to

!a$ricate unch and die in a single cut

Fther tools and arts +ith intricate outline shaes such

as lathe !orm tools e#trusion dies and !lat temlates

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Irregular outline cut from a

solid slab by wire EDM (photo

courtesy of LeBland Makino

Machine Tool Co!

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7ses high "elocity stream o! electrons !ocused on

+or-iece sur!ace to remo"e material $y melting

and "aori0ation

Electron !eam Machining (E!M)

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#-M Operaion

E gun accelerates a continuous stream o! electrons toa$out G5@ o! light seed

eam is !ocused through electromagnetic lens reducing

diameter to as small as =.=25 mm '=.==1 in(

Fn iminging +or- sur!ace -inetic energy o! electrons is

con"erted to thermal energy o! e#tremely high density

+hich melts or "aori0es material in a "ery locali0ed area

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#-M Applicaions

*or-s on any material Ideal !or micromachining

)rilling small diameter holes do+n to =.=5 mm '=.==2

in(

Cutting slots only a$out =.=25 mm '=.==1 in.( +ide

)rilling holes +ith "ery high deth to diameter ratios

>atios greater than 1==:1

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7ses the light energy !rom a laser to remo"ematerial $y "aori0ation and a$lation

"aser !eam Machining ("!M)

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Laser

aser H ight amli!ication $y stimulated emission o!radiation

aser con"erts electrical energy into a highly coherent

light $eam +ith !ollo+ing roerties:

Monochromatic 'single +a"e length(

ighly collimated 'light rays are almost er!ectly

arallel(

These roerties allo+ laser light to $e !ocused using

otical lenses onto a "ery small sot +ith resulting high

o+er densities

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L-M Applicaions

)rilling slitting slotting scri$ing and mar-ingoerations

)rilling small diameter holes do+n to =.=25 mm '=.==1

in(

;enerally used on thin stoc-

*or- materials: metals +ith high hardness and strength

so!t metals ceramics glass and glass eo#y lastics

ru$$er cloth and +ood

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Laser beam cutting

operation performed on

sheet metal (photo courtesy

of "#C Corp!

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7ses lasma stream oerating at "ery hightemeratures to cut metal $y melting

#lasma Arc Cutting (#AC)

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Operaion o" !AC

Plasma H a suerheated electrically ioni0ed gas PAC temeratures: 1====

C to 14===

C '1===

B to

25===

B(

Plasma arc generated $et+een electrode in torch and

anode +or-iece

The lasma !lo+s through +ater cooled no00le thatconstricts and directs stream to desired location

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Applicaions o" !AC

Most alications o! PAC in"ol"e cutting o! !lat metalsheets and lates

ole iercing and cutting along a de!ined ath

Can $e oerated $y hand held torch or automated $y

C,C

Can cut any electrically conducti"e metal

Most !re%uently cut metals: car$on steel stainless steel

aluminum

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Air Carbon Arc Cuin$

Arc is generated $et+een a car$on electrode and metallic+or- and high "elocity air 8et $lo+s a+ay melted ortion

o! metal

Can $e used to !orm a -er! to se"er a iece or to gouge a

ca"ity to reare edges o! lates !or +elding

*or- materials: cast iron car$on steel alloy steels and"arious non!errous alloys

attering o! molten metal is a ha0ard and a

disad"antage

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Oher Arc Cuin$ !rocesses

,ot as +idely used as lasma arc cutting and air car$onarc cutting:

;as metal arc cutting

hielded metal arc cutting

;as tungsten arc cutting

Car$on arc cutting

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O0y"uel Cuin$ &O1C' !rocesses

7se heat o! com$ustion o! !uel gases com$ined +ithe#othermic reaction o! metal +ith o#ygen

Poularly -no+n as !lame cutting

Cutting torch deli"ers a mi#ture o! !uel gas and o#ygen

and directs a stream o! o#ygen to cutting region

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Operaion o" O1C !rocesses

Primary mechanism o! material remo"al is chemicalreaction o! o#ygen +ith $ase metal

Esecially in cutting !errous metals

Purose o! o#y!uel com$ustion is to raise the

temerature to suort the reaction

Commonly used to cut !errous metal lates

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O1C Applicaions

Per!ormed manually or $y machine Manual oeration e#amles o! alications:

>eair +or-

Cutting scra metal

Trimming risers !rom sand castings Machine !lame cutting allo+s !aster seeds and greater

accuracies

Machine oeration o!ten C,C controlled to cut

ro!iled shaes

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!ossible !ar Geomery 1eaures

Dery small holes oles +ith large deth to diameter ratios

oles that are not round

,arro+ slots in sla$s and lates

Micromachining hallo+ oc-ets and sur!ace details in !lat arts

ecial contoured shaes !or mold and die alications

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(or, Maerials

As a grou the nontraditional rocesses can $e aliedto metals and non metals

o+e"er certain rocesses are not suited to certain

+or- materials

e"eral rocesses can $e used on metals $ut not

nonmetals:

ECM

E)M and +ire E)M

PAC

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Hybrid Machinin$

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Hybrid Machinin$

Com$ination o! t+o 'or more( 7sed to imro"e the machining er!ormance 'high

remo"al rate & $etter sur!ace %uality(

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Ad"anced machining rocesses ha"e uni%uecaa$ilities and utili0e chemical electrochemical

electrical and highenergy$eam sources o! energy.

The mechanical roerties o! the +or-iece material are

not signi!icant $ecause these rocesses rely onmechanisms that do not in"ol"e the strength hardness

ductility or toughness o! the material. >ather they

in"ol"e hysical chemical and electrical roerties.

Summary

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Chemical and electrical methods o! machining aresuita$le articularly !or hard materials and comle#

shaes.

They do not roduce !orces 'and there!ore can $e used

!or thin slender and !le#i$le +or-ieces( signi!icanttemeratures or residual stresses.

o+e"er the e!!ects o! these rocesses on sur!ace

integrity must $e in"estigated as they can damage

sur!aces considera$ly thus reducing the !atigue li!e o!the roduct.

Summary

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ighenergy$eam machining rocesses $asically utili0e

laser $eams electron $eams and lasma $eams.

They ha"e imortant industrial alications ossess a

high !le#i$ility o! oeration +ith ro$otic controls and are

cometiti"e economically +ith "arious other rocesses.

*ater8et machining a$rasi"e +ater8et machining and

a$rasi"e8et machining rocesses can $e used !or cutting

as +ell as de$urring oerations. ecause they do not

utili0e hard tooling they ha"e an inherent !le#i$ility o!

oeration.

Summary

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Than, 2ou