welding technology

1. CA-1 Assignment Advance Welding
Technology
PE-ME702H

2. Table ofContent
• What is welding
• What is friction
• Friction Welding Principle
• Working
• Types
• Application
• Advantages

3. • Disadvantages
What Is Welding
• Welding is a fabrication process that joins materials, usually metals or
thermoplastics, by using high heat to melt the parts together and
allowing them to cool, causing fusion. Welding is distinct from lower
temperature techniques such as brazing and soldering, which do not
melt the base metal (parent metal).

4. • In addition to melting the base metal, a filler material is typically added to
the joint to form a pool of molten material (the weld pool) that cools to
form a joint that, based on weld configuration (butt, full penetration,
fillet, etc.), can be stronger than the base material. Pressure may also be
used in conjunction with heat or by itself to produce a weld. Welding also
requires a form of shield to protect the filler metals or melted metals from
being contaminated or oxidized.

5. • Many different energy sources can be used for welding, including a gas
flame (chemical), an electric arc (electrical), a laser, an electron beam,
friction, and ultrasound. While often an industrial process, welding may
be performed in many different environments, including in open air,
under water, and in outer space. Welding is a hazardous undertaking and
precautions are required to avoid burns, electric shock, vision damage,
inhalation of poisonous gases and fumes, and exposure to intense
ultraviolet radiation.
What Is Friction
• Friction is the force resisting the relative motion of solid surfaces,
fluid layers, and material elements sliding against each other.[2]
There are several types of friction:
• Dry friction is a force that opposes the relative lateral motion of two
solid surfaces in contact. Dry friction is subdivided into static friction
("stiction") between non-moving surfaces, and kinetic friction

6. between moving surfaces. With the exception of atomic or
molecular friction, dry friction generally arises from the interaction
of surface features, known as asperities (see Figure 1).
• Fluid friction describes the friction between layers of a viscous fluid
that are moving relative to each other.[3][4]
• Figure 1: Simulated blocks with fractal rough
surfaces, exhibiting static frictional interactions[1]
• Lubricated frictionis a case of fluid friction where a lubricant fluid separates two solid
surfaces.[5][6][7]

7. • Skin frictionis a component of drag, the force resisting the motion of a fluid across the surface
of a body.
• Internal frictionis the force resisting motion between the elements making up a solid material
while it undergoes deformation.[4]
• When surfaces in contact move relative to each other, the friction between the two surfaces
converts kinetic energy into thermal energy (that is, it converts work to heat). This property
can have dramatic consequences, as illustrated by the use of friction created by rubbing
pieces of wood together to start a fire. Kinetic energy is converted to thermal energy
whenever motion with friction occurs, for example when a viscous fluid is stirred. Another
important consequence of many types of friction can be wear, which may lead to
performance degradation or damage to components. Friction is a component of the science
of tribology.
• Friction is desirable and important in supplying traction to facilitate
motion on land. Most land vehicles rely on friction for acceleration,
deceleration and changing direction. Sudden reductions in traction
can cause loss of control and accidents.
• Friction is not itself a fundamental force. Dry friction arises from a
combination of inter-surface adhesion, surface roughness, surface

8. deformation, and surface contamination. The complexity of these
interactions makes the calculation of friction from first principles
impractical and necessitates the use of empirical methods for
analysis and the development of theory.
• Friction is a non-conservative force – work done against friction is
path dependent. In the presence of friction, some kinetic energy is
always transformed to thermal energy, so mechanical energy is not
conserved.
• Friction Welding Principle
• Friction welding works on basic principle of friction. In
this welding process, the friction is used to generate heat
at the interference surface. This heat is further used to
join two work pieces by applying external pressure at the

9. surface of work piece. In this welding process, the
friction is applied until the plastic forming temperature is
achieved. It is normally 900-1300 degree centigrade for
steel. After this heating phase, a uniformly increasing
pressure force applied until the both metal work pieces
makes a permanent joint. This joint is created due to
thermo mechanical treatment at the contact surface.
Working
• There are many types of friction welding processes which
works differently. But all different these processes involves
common a working principle which can be summarize as
follow.

10. • First both the work pieces are prepared for smooth square surface. One
of them is mounted on a rotor driven chuck and other one remains
stationary.
• The rotor allows rotating at high speed thus it makes rotate mounted
work piece. A little pressure force is applied on the stationary work piece
which permits cleaning the surface by burnishing action.

11. • Now a high pressure force applied to the stationary work piece which
forces it toward rotating work piece and generates a high friction force.
This friction generates heat at the contact surface. It is applied until the
plastic forming temperature is achieved.
• When the temperature is reached the desire limit, the rotor is stopped
and the pressure force is applied increasingly until the whole weld is
formed.
• This welding is used to weld those metals and alloys which cannot be
welded by other method.
Types:
Continuous induce frictionwelding

12. • This welding is same as we discussed above. In this welding
process, the rotor is connected with a band brake. When the
friction crosses the limit of plastic temperature, the band
brake comes into action which stops the rotor but the
pressure applied on the work piece increasingly until the
weld is formed.
•
Inertiafriction welding:

13. • In this type of friction welding the band brake is replaced by
the engine flywheel and shaft flywheel. These flywheels
connect chuck to the motor. In the starting of the welding,
both flywheels are connected with one another. When the
speed or friction reaches its limit, the engine flywheel
separated from the shaft flywheel. Shaft flywheel has low
moment of inertia which stops without brake. The pressure
force is continuously applied to the work piece until the weld
is formed.
•

14. Application
• For welding tubes and shafts.
• It is mostly used in aerospace, automobile, marine and oil industries.
• Gears, axle tube, valves, drive line etc. components are friction welded.
• It is used to replace forging or casting assembly.
• Hydraulic piston rod, truck rollers bushes etc. are join by friction welding.
• Used in electrical industries for welding copper and aluminum
equipment’s.
• Used in pump for welding pump shaft (stainless steel to carbon steels).
• Gear levers, drill bits, connecting rod etc. are welded by friction welding.

15. Advantages
• It is environment friendly process without generation smoke etc.
• Narrow heat affected zone so no change in properties of heat
sensitive material.
• No filler metal required
• It is environment friendly process without generation smoke etc.
• Narrow heat affected zone so no change in properties of heat
sensitive material.
• No filler metal required

16. Disadvantages
• This is mostly used only for round bars of same cross section.
• Non-forgeable material cannot be weld.
• Preparation of work piece is more critical
• High setup cost.
• Joint design is limited.
Thankyou