TO COVER ALL WELDING PROCESSES

1. ADVANCED WELDING TECHNIQUES
K.RAVI NEEL
M.CHAKRADHAR
P.VAMSI KRISHNA
B.SANKARA RAO

3. Welding is a process for joining two similar or dissimilar
metals by fusion. It joins different metals/alloys, with or
without the application of pressure and with or without
the use of filler metal.
The fusion of metal takes place by means of heat. The
may be generated either from ‘’combustion of gases,
electric arc, electric resistance, chemical reaction, frictional
heat, or by sound and light energy’’.
WELDING IS USED FOR MAKING PERMANENT JOINT
The Advanced welding is used for generating high
temperature in localised zones to melt the material
INTRODUCTION:

4. TYPES OF ADVANCED WELDING TECHNIQUES:
FRICTION WELDING
EXPLOSIVE WELDING
LASER WELDING
PLASMA WELDING
RESISTANCE WELDING
THERMIT WELDING
FRICTION WELDING
EXPLOSIVE WELDING
LASER WELDING
PLASMA WELDING
RESISTANCE WELDING
THERMIT WELDING

5. EXPLANATION:
1.FRICTION WELDING;
Friction welding is a solid state welding
process that generates heat Through
Mechanical Friction between work pieces
in relative motion to one another.
In Friction Welding (Inertia Welding) One part
rotated, one stationary .Stationary part forced
against rotating part . Friction converts kinetic
energy to thermal energy Metal at interface
melts and is joined.

6. This process is limited to angular and flat butt joints.
Preparation of work piece is more critical than making a weld.
Cost of setup of machine is very high.
It can only be used for smaller parts of machines , big parts are
not compatible in it.
It can produce high quality of welds in a short period of time.
No filler metal and flux is used in this process.
In this process less skill is required to use it.
ADVANTAGES
DISADVANTAGES
APPLICATIONS
It is used to make tubes and shafts.
It is mostly used in aerospace , automobile, marine and oil industries.
Used in electrical industries for welding copper and ALUMINUM equipment’s.

7. 2.EXPLOSIVE WELDING;
Explosion welding (EXW) is a solid
state process where welding is accomplished
by accelerating one of the components at
extremely high velocity through the
use of chemical explosives.
This process is most commonly utilized to
clad carbon steel plate with a thin layer
of corrosion resistant material (e.g., stainless
steel, nickel alloy, titanium, or zirconium)
Explosive welding differs from other traditional
joining processes as it does not depend on melting
of two metals to be joined, or on plastic
deformation

8. Explosion welding can produce a bond between two metals that cannot
necessarily be welded by conventional means.
Large areas can be bonded extremely quickly.
DISADVANTAGES
Extensive knowledge of
explosives is needed before the
procedure may be attempted
safely
Regulations for the use of high
explosives may require special
licensing.
APPLICATIONS
For welding large plates which cannot weld by other
processes
ADVANTAGES

9. 3.LASER BEAM WELDING;
Laser beam welding (LBW) is a welding technique
used to join pieces
of metal or thermoplastics through the use of a laser.
The beam provides a concentrated heat source.
allowing for narrow, deep welds and high
welding rates.
It is based on keyhole or penetration mode welding
The spot size of the laser can vary between 0.2 mm
and 13 mm, though only smaller sizes
are used for welding.
The depth of penetration is proportional to the
amount of power supplied, but is also dependent
on the location of the focal poin.

10. ADVANTAGES;
The laser beam can be transmitted through air
rather than requiring a vacuum the process
It is easily automated with robotic machinery.
LBW results in higher quality welds.
The welding plants are expensive, depending upon
the equipment.
If filler material is necessary they are, because of
the limited amount produced, relatively expensive
DISADVANTAGES
APPLICATIONS
The process is frequently used in high volume applications
using automation, such as in the automotive industry.
LBW is a versatile process, capable of welding carbon
steels, , stainless steel, aluminum, and titanium

11. 4.Thermite welding;
Thermite welding is a liquid state chemical welding
process, in which joint formation takes place in
molten state. Practically, it is combination of welding
and casting process in which, the molten iron
poured at the welding plates and allow solidifying to
make a permanent strong joint.
In this type of welding, a mixture of Aluminum and
iron oxide is used in ratio 1:3 by weight.
which can handle temperature around 3000 degree
centigrade.
In the thermite welding mould is created by either
graphite or sand. Graphite moulds are permanent
mould which is used to make various similar joints.
Sand mould are used where the joint design is
different every time.

12. ADVANTAGES
Metal joining rate is high.
Thermite welding can be done at site where
casting is impossible.
This can be used where power supply is
not available.
DISADVANTAGES
It is used for limited metals like iron and
copper.
It is uneconomical for welding light parts.APPLICATIONS
It is mostly used to weld railroad at the site.
They are used to repair heavy castings.
It is used to make structure joints in large
ships

13. 5.Plasma arc welding;
Plasma arc welding (PAW) is an arc welding process.
The electric arc is formed between an electrode (which is usually
made of sintered tungsten) and the workpiece.
plasma arc can be separated from the shielding gas envelope.
The plasma is then forced through a fine-bore copper nozzle
which constricts the arc and the plasma exits the orifice at high
velocities (approaching the speed of sound) and a temperature
approaching 28,000 °C (50,000 °F) or higher.
Arc plasma is the temporary state of a gas. The gas gets ionized
after passage of electric current through it and it becomes a
conductor of electricity. In ionized state atoms break into
electrons (−) and cations (+) and the system contains a mixture of
ions, electrons and highly excited atoms

14. APPLICATIONS
ADVANTAGES
DISADVANTAGES
Good arc stability and excellent weld quality
Better penetration control than other processes.
Can be used to weld any metals.
High equipment cost.
Large torch than other welding processes.
For welding work piece up to 25 mm thick,
joints like square butt, J or V are employed.
Plasma welding is used to make both key hole
and non-key hole types of welds.

15. RESISTANCE WELDING;
It is a fusion welding process that
use a heat and pressure
where heat to form the weld is
generated by the electrical
resistance of material combined with
the time and the force used to hold
the materials together during
welding.
Electrical current (100–100,000 A) is
passed through the metal.

16. Seam welding;
Resistance seam welding is a process that
produces a weld at the faying surfaces of two
similar metals.
The seam may be a butt joint or an overlap
joint and is usually an automated process.
seam welding relies on two electrodes,
usually made from copper, to apply pressure and
current. The electrodes are often disc shaped
and rotate as the material passes between them.
This allows the electrodes to stay in constant
contact with the material to make long
continuous welds. The electrodes may also move
or assist the movement of the material.

17. ADVANTAGES
Gas tight as well as liquid tight joints can be made.
The Overlap is less than spot or projection welding.
The production of single seam weld and parallel seams can be
got simultaneously.
The welding process is restricted to a straight line or uniformly curved
line.
The metals sheets having thickness more than 3mm can cause problems
while welding.
DISADVANTAGES
APPLICATIONS
Gasoline tanks
Various sheet metal containers

18. These welding s are should be carried out by
experienced welders only.
Should be wear protective elements.
These welding techniques are used in many sectors
Like automobiles, marine , aeronautical , aero
space .