3.  Contents
 Solid state welding
 Cold welding
 Ultrasonic welding
 Friction welding
 Resistance welding

4.  It is defined as metal pieces or parts that are
join together by heating the surfaces to the
point of melting with electric arc, hammering
etc.

5.  Def:
 A group of welding processes that join metals
at temperatures essentially below the melting
points of the materials, without the addition of
a brazing filler metal. Pressure may or may not
be applied to the joint. Examples include cold
welding , ultrasonic wielding, friction wielding
etc.

6.  Cold welding is a solid state process in which
pressure is used at room temperature to
produce coalescence of metals with substantial
deformation at the weld. both butt and lap
joints can be cold welded.

7.  At least one of the metals must be ductile
without excessive work hardening
 Total absence of applied heating
 Dissimiliar metals can be jointed.
 Surface preparation is important.

8.  A manually
operated cold
welding
equipment

9.  The parts to be welded
are first cleaned
 A short section of the
part is sheared
 The parts are clamped
in a die with some
initial extention
 A forging force is
applied to complete
welding.
Dies
Workpiece Workpiece
Before welding
After welding

10.  Cold welded butt joints are used in the
manufacturing of aluminium ,copper
,gold, silver, and platinum wire.
 Most commonly, successive reels of wire are
joined for continuous drawing to a smaller
diameter.
 Manufacture of kitchen utensils.

11.  Def:
 A solid state welding process in which
coalescence is produced at the faying surfaces
by the application of high frequency vibratory
energy while the work pieces are held together
under moderately low static pressure.

12.  Components of
ultrasonic welding
system include
 1)transducer
 2)sonotrode
 3)anvil
Anvil
Mass
Sonotrode
tip
Clamping
force
wedge Transducer
Force
Weldment
Vibration

13.  A static clamping
force is applied
perpendicular to the
interface between the
work pieces.
 The contacting
sonotrode oscillates
parallel to the
interface.
 Combined effect of
static and oscillating
force produces
deformation which
promotes welding.
Anvil
Mass
Sonotrode
tip
Clamping
force
wedge Transducer
Force
Weldment
Vibration

14.  No heat is applied and no melting occurs.
 Permits welding of thin to thick sections.
 Welding can be made through some surface
coatings.
 Pressures used are lower ,welding times are
shorter, and the thickness of deformed regions
are thinner than for cold welding.

15.  The thickness of the component adjacent to the
sonotrode tip must not exceed relatively thin
gages because of power limitations of the
equipment.
 Process is limited to lap joints.
 Butt welds can not be made because there is no
means of supporting the work pieces and
applying clamping force.

16.  Def:
Friction welding is a solid state joining process
that produces coalescence by the heat
developed between two surfaces by
mechanically induced surface motion.

17.  1)continuous drive friction welding
 2)inertia welding

18.  One of the work pieces is
attached to a rotating motor
drive, the other is fixed in an
axial motion system.
 One work pieces is rotated at
constant speed by the motor.
 An axial or radial force is
applied.
 The work pieces are brought
together under pressure for a
predetermined time, or until
a preset upset is reached
 Then the drive is disengaged
and a break is applied to the
rotating work piece.
Workpieces
Non-rotating viseMotor
Chuck
Spindle
Hydraulic cylinder
Brake

19.  Frequently competes with flash or upset
welding when one of the work pieces to be
joined has axial symmetry.
 Used in automotive industry to manufacture
gears, engine valves, and shock absorbers.
 Used to join jet engine compressor parts.

21.  One of the work piece is
connected to a fly
wheel; the other is
clamped in a non
rotating axial drive.
 The fly wheel is
accelerated to the
welding angular
velocity.
 The drive is disengaged
and the work piece are
brought together
 Frictional heat is
produce at the interface.
An axial force is
required to complete
welding.
Spindle
Workpieces
Non-rotating chuck
Hydraulic cylinder
FlywheelMotor
Chuck

23.  In both mechanism welding heat is developed
by frictional heat and plastic deformation
 Both method use axial force for upsetting
purpose.
 In both mechanism axial pressure may be
changed at the end of the rotation

24. Continuous drive
1)One of the work pieces
directly connected to a
rotating motor drive.
2)Rotational speed may be
constant until the brake is
applied.
3)Rotational energy of the
work piece dissipates
through friction and plastic
deformation, producing
welding heat.
Inertia drive
1)One of the work piece
is connected to the fly
wheel.
2)Rotational speed
decreases continuously
to zero during the
process.
3)Kinetic energy of the
fly wheel is dissipates
through friction and
plastic deformation

25.  The resistance welding process involves the joining of
materials through the resistance of an electrical
current. The electrical current generates heat and
pressure which creates bonds between the parts being
welded. Most resistance welding applications are
applied to metals, but plastic materials may also be
used. This quick and efficient application uses
machines with copper electrodes that inject materials
with heat. Once the desired amount of heat is injected,
the materials begin to cool; a bond is formed during the
cooling process. What makes resistance welding
different than regular welding is it uses both heat and
pressure to weld, while regular welding only used
heat.

26.  There are six different resistance welding
processes; each process involves the formation
of a bond through heat produced by an
electrical current and pressure created by the
electrodes to hold the materials together.

27.  1)Resistance Spot Welding- This is when a bond is
formed at the joining surface of the material being
welded.
 2)Projection Welding- This involves the bonding of
metal materials.
 3)Flash Welding- This is when a bond is formed over
the entire area of the welded materials.
 4)Upset Welding- This process connects materials
progressively along a joint.
 5)Percussion Welding- This is the welding of materials
through heat produced by an arc due to a rapid
discharge of energy.
 6)High Frequency Resistance Welding- This is the

28.  High speed< 0.1 seconds in automotive spot
welds
 Excellent for sheet metal applications, < ¼-inch
 No filler metal

29.  Higher equipment costs than arc welding
 Nondestructive testing
 Low tensile and fatigue strength
 Not portable
 Lap joint require additional metal.