Final Friction Welding

8/3/2019 Final Friction Welding

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FRICTION WELDINGPresented by:

Kapil Mahajan

Ankit Dua

Sandeep


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Work taken over by group

1. Convert a simple lathe machine to use offriction welding.

2. To study the effect of various parameterson Friction welding.

3. Study the change In microstructure ofmaterials due to heat generation


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Welding is a fabrication or sculptural process that joins materials,

usually metals or thermoplastics, by causing coalescence. This is often

done by melting the work pieces and adding a filler material to form a

pool of molten material (the weld pool) that cools to become a strong

joint, with pressure sometimes used in conjunction with heat, or by itself,

to produce the weld. Many different energy sources can be used for

welding, including a gas flame, an electric arc, a laser, an electron

beam, friction, and ultrasound. While often an industrial process,

welding may be performed in many different environments, includingopen air, under water and in outer space.


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SolidState

Welding

Electrical

Chemical

Mechanical

FrictionPressure &

Deformation

Friction

Weld


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A simple explanation defines the friction welding process as rotating one

component against a fixed component under pressure. This action

efficiently prepares and cleans the weld interface, and generatessufficient low temperature, frictional heat, for at least one of the

materials to become plastic at the joint interface. This "Solid State" (non-

melting), joining process produces a merging between the materials via

the heat developed by the induced rubbing motion, and the applied loadbetween the two surfaces. At this point, rotation stops rapidly and the

components are forged together.


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DEFINITION OF FRICTION WELDING

Friction welding is asolid state joiningprocess thatproducescoalescence by theheat developedbetween two

surfaces bymechanicallyinduced surfacemotion.


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CATEGORIES OF FRICTION WELDING

Continuous driveInertia


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CONTINUOUS DRIVE FRICTION WELDING

One of the workpiecesis attached to arotating motor drive,

the other is fixed in anaxial motion system.

One work piece isrotated at constant

speed by the motor. An axial or radial force

is applied.

Continuous Drive

Workpieces

Non-rotating viseMotor

Chuck

SpindleHydraulic cylinder

Brake


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CONTINUOUS DRIVE FRICTION WELDING

The work pieces arebrought togetherunder pressure for a

predeter-mined time,or until a presetupset is reached.

Then the drive is

disengaged and abreak is applied tothe rotating workpiece.

Continuous Drive

Workpieces

Non-rotating viseMotor

Chuck

SpindleHydraulic cylinder

Brake


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INERTIA WELDING PROCESSDESCRIPTION

1. One of the work pieces is

connected to a flywheel;the other is clamped in anon-rotating axial drive

2. The flywheel isaccelerated to the welding

angular velocity.3. The drive is disengaged

and the work pieces arebrought together

1. Frictional heat is producedat the interface. An axialforce is applied tocomplete welding.

Spindle

Workpieces

Non-rotating chuck

Hydraulic cylinder

FlywheelMotor

Chuck


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1. Original diameter of pulley available at shaft end: 5 inches

2. Original diameter of pulley available at lathe end: 8 inches3. Diameter of pulley used at motor end: 8 inches

4. Diameter of pulley used at lathe end : 5 inches

5. No change was made to the gear ratio

6. Motor with .5 horse power was tried but was unsuccessful

7. Finally motor with 1 horse power was used

8. RPM achived at chuck :1950


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1. The properties of the steel depends upon the microstructure.

decreasing the size of the grains and decreasing the amount of

pearlite improves the strength, ductility and the toughness of the

steel.

2. The dark regions are the cementite. It is made up from a fine mixture

of ferrite and iron carbide, which can be seen as a "wormy" texture.3. The light colored region of the microstructure is the ferrite. The grain

boundaries between the ferrite grains can be seen quite clearly.

4. The group agrees to the fact that strength increases with decrease in

pearlite structure because in our project we see after the welding

pearlite structure reduces and torsional strength increases


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1. Length of specimen before welding: 166.0mm(MS), 170(AL)

2. Length of specimen before testing :160.8mm (MS), 160(AL)

3. Length of specimen after testing : 166.9 mm(MS) ,172(AL)4. Diameter of specimen :16 mm(MS), 8mm (AL)


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strain

s

t

r

e

s

s


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D i g t il t ti g f m t i l m l th stress strain curve i


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During tensile testing of a material sample, the stressstrain curve is a

graphical representation of the relationship between stress, derived from

measuring the load applied on the sample, and strain, derived from

measuring the deformation of the sample, i.e. elongation, compression,

or distortion. The slope of stress-strain curve at any point is calledthe tangent modulus; the slope of the elastic (linear) portion of the curve

is a property used to characterize materials and is known as the Young's

modulus. The area under the elastic portion of the curve is known as the

modulus of resilience.

The nature of the curve varies from material to material. The following

diagrams illustrate the stressstrain behaviour of typical materials in

terms of the engineering stress and engineering strain where the stress

and strain are calculated based on the original dimensions of the sample

and not the instantaneous values.

Mild steel generally exhibits a very linear stress strain relationship up to


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Mild steel generally exhibits a very linear stressstrain relationship up to

a well defined yield point. The linear portion of the curve is the elastic

region and the slope is the modulus of elasticity or Young's Modulus.

After the yield point, the curve typically decreases slightly .As

deformation continues, the stress increases on account of strainhardening until it reaches the ultimate strength. Until this point, the

cross-sectional area decreases uniformly because of Poisson

contractions. The actual rupture point is in the same vertical line as the

visual rupture point.

However, beyond this point a neck forms where the local cross-sectional

area decreases more quickly than the rest of the sample resulting in an

increase in the true stress. ,curve is plotted in terms of true stress and true

strain the stress will continue to rise until failure. Eventually the neck

becomes unstable and the specimen ruptures (fractures).


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displacement

l

o

a

d


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1. Max Tensile strength of mild steel: 45kn2. Max Torsional strength of mild steel: 50kn

3. Tensile strength of our tested specimen: 30kn

4. Torsional strength of our tested specimen: 57.6kn

5. Max tensile strength of aluminum: 35 kn6. Max torsional strength of aluminum: 29kn

7. Max torsional strength of our tested specimen: 37kn


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MILD 95 94 95 95 94 96


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STEEL

BEFOR

WELDI

NG

ALUMINUMBEFOREWELDING

79 80 80 80 78 80

MILDSTEELAFTERWELDING

120 116 95 95 96 94

ALUMINUMAFTERWELDING

94 90 80 79 79 80


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AWS Welding Handbook


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1. ENVIORMENT FRIENDLY

2. SAFE FOR USE3. CAN BE USED FOR MASS PRODUCTION

4. MOST IMPORTANTLY IT CAN BE VIEWED BY NAKED EYE

5. SMALL HEAT AFFECTED ZONES

6. JOINT ENDS UP STRONGER THAN PARENT MATERIAL7. LOW ENERGY CONSUMPTION

8. CHEAPER IN COST

9. SHORT TIME CYCLE

10. LESS PREPRATION OF SPECIMEN


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1. Join highly dissimilar metal combination to optimize your products'

quality and properties.

2. Little cost variation with weld size.

3. Save labor, material, and operations through near net size design.

4. No part length problems.


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WIDE APPLICATIONS Bimetallic Engine Valve

Brake Calliper Steering Shaft Air Brake Push Pad Assembly Universal Joint Yoke Drive Axle Shaft

Shift Lever Turbine Shaft Diesel Injector Helicopter Rotor Shaft Twist Drill ,Lathe Spindle Blank Drill Pipe Gear Hub Valve Body Eccentric Shaft


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DISADVANTAGE OF FRICTION WELDING Grain Growth

A wide T will exist between base metal and HAZ.Preheating and cooling methods will affect the brittlenessof the metal in this region

Inclusions

Impurities or foreign substances which are forced into theweld puddle during the welding process. Has the same

effect as a crack. Segregation

Condition where some regions of the metal are enrichedwith an alloy ingredient and others arent. Can beprevented by proper heat treatment and cooling.

Porosity The formation of tiny pinholes generated by atmospheric

contamination. Prevented by keeping a protective shieldover the molten weld puddle.

Residual Stresses

Rapid heating and cooling results in thermal stressesdetrimental to joint strength.


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1. COST OF RAW MATERIAL PURCHASED: RS 350

2. MONEY SPENT ON SPECIMEN TESTING : RS 1200

3. MOTOR PURCHASED FOR: RS 8004. MISCLENIOUS EXPENSES: RS 500


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THANKS

Final Friction Welding

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