solid state welding process

7/21/2019 Solid State Welding Process

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Solid-State WeldingProcess



Cold Welding Cold Weldin

g

Pressure is applied to theworkpieces through dies orrolls

Preferably both work piecesshould be ductile

The work pieces should

cleaned thoroughly

Can not join dissimilarmetals

Fig: The roll bonding or cladding process



Ultrasonic Welding Ultrasonic Weld

ing

Surfaces of the twocomponents aresubjected to a staticforces and oscillating

shearing force

Produces a strong,solid-state bond

Versatile and reliablefor joining metals

Fig: a) Components of an ultrasonic welding machinefor lap welds.The lateral vibration of the tool tipcause plastic deformation and bonding at theinterface of the work piece b)Ultrasonic some welding using a roller c)An ultrasonically weldedpart



Friction Welding Friction Weldin

g

Developed in the 194 !s

Parts are circular in shape

Can be used to join a wide variety of materials

Fig: e!uence of operation in the friction welding process ")#eft$hand component is rotated at high speed. %)&ight$hand component is brought into contact under an a'ial force ()A'ial force is increased the flash begins toform *) #eft$hand component stops rotating weld is completed.The flash can subse!uently be removed bymachining or grinding



Friction Welding Friction Weldin

g

Process can be fully automated

Can weld solid steel bars up to "# mm in outside diameter

Fig: hape of friction +one in friction welding,as a function of the force applied and the rotational speed



Inertia Friction Welding Inertia Friction Weldin

g $odi%cation of &riction 'elding

(nergy is supplied by a )y wheel

The parts are pressed together by a normal force

*s friction at the interface increases+ the )y wheel slows down

The weld is completed when the )ywheel stops

Fig : The principle of thefriction stir weldingprocess. Aluminum$alloy plates up to- mm /(in) thick havebeen welded by thisprocess



Linear Friction Welding Linear Friction Weldin g

Parts are joined by a linear reciprocating motion

Parts do not have to be circular or tubular

,n this application+ one part is moved across the faceof the other part using a balanced reciprocatingmechanism



Friction Stir Welding (FSW) Friction Stir Weld ing (FSW)

-ew Process for welding aerospace metals

.esearch is being directed towards using thisprocess for polymers

&/' uses a 0 rd nonconsumable tool insertedbetween the two bodies to heat the material tobe joined



Resistance Welding Resistance We lding

Developed in the early 19 !s

* process in which the heat re uired for welding is

produced by means of electrical resistance acrossthe two components

.' does not requiring the following 2

Consumable electrodes

/hield gases

&lu3



Resistance Spot Welding Resistance S pot Welding

./' uses the tips of two opposing solid cylindrical electrodes

Pressure is applied to the lap joint until the current is turnedo in order to obtain a strong weld

Fig: /a) e!uence in the resistance spot welding



Resistance Spot Welding Resistance S pot Welding

/urfaces should be clean

*ccurate control of and timing of electric current and of pressureare essential in resistance welding

Fig: b)Cross$section of a spot weld,showing the weldnugget and the indentation of the electrode onthe sheet surfaces.This is one of the mostcommonly used process in sheet$metalfabrication and in automotive$body assembly



Resistance Seam Welding Resistance Seam Weldin g ./($ is modi%cation of spot welding wherein the electrodes are replacedby rotating wheels or rollers

The electrically conducting rollers produce a spot weld

./($ can produce a continuous seam 5 joint that is li uid and gas tight

Fig : /a) eam$0elding 1rocess in which rotating rolls act as electrode /b)2verlapping spots in a seam weld. /c) &oll spot weld /d) &esistance$welded gasoline tank



Resistance Projection Welding Resistance Pro jection Welding

.P' is developedby introducing highelectricalresistance at a jointby embossing one

or more projectionson the surface tobe welded

'eld nuggets aresimilar to spotwelding

Fig: a) &esistance pro3ection 0elding b)A welded bracket c) 4

d) 1ro3ection welding of nuts r threaded hosses and stack



Resistance Projection Welding Resistance Pro jection Welding

The electrodes e3ert pressure to compressthe projections

-uts and bolts can be welded to sheet andplate by this process

$etal baskets+ oven grills+ and shopping

carts can be made by .P'



Flash Welding Flash Weld ing 6eat is generated from the arc as the ends as the two memberscontacts

*n a3ial force is applied at a controlled rate

'eld is formed in plastic deformation

Fig : /a)Flash$welding process for end$to 5end welding of solid rods or tubular parts

/b) 4 /c) Typical parts made by flash welding /d)6esign 7uidelines for flash welding



Stud Welding Stud Weldin g /mall part or a threaded rod or hanger serves as a electrode

*lso called as /tud arc weldingPrevent o3idation to concentrate the heat generation

Portable stud7welding is also available

Fig:The se!uence of operation in stud welding,which is used for welding bars threaded rods and variousfasteners onto metal plates

solid state welding process

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