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Presented by
Dr. K. Ravi Kumar,
KPR Institute of Engineering and Technology
Coimbatore.
Dr.K.Ravi Kumar

2. Cladding
• Cladding - Metallurgical process in which layers of metal
having different properties are bonded together to form a
composite material .
• Does not use any fillers or adhesive materials.
• Bonding takes place with the help of extreme pressure in
presence or absence of heat.
• Capable of producing metals with two layers, three layers and
upto seven layers or even more depending on the materials.
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Dr.K.Ravi Kumar

3. Cladding
Cladding metallic bonding generally involves three-stages namely:
• Establishment of physical contact
• Activation of contact surfaces
• Interaction within joining metals by hot or cold process
Caldding Methods
• Roll Bonding
• Accumulative Rolling Bonding
• Friction Surface cladding
• Laser Cladding
• Microwave cladding
• Rotary swaging
• Plasma Surface Cladding
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Dr.K.Ravi Kumar

4. Roll Bonding
• Solid phase process in
which the metals are
bonded by rolling at an
applied pressure.
• Layer of two or more
metals in the form of
sheets, strips or plates
are piled over each
other.
•
• Roll bonded to achieve
an appropriate bonding
between the metals.
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Dr.K.Ravi Kumar

5. Roll bonding parameters
• Suitable for ductile materials
• A maximum of 50 % reduction in thickness or sometimes even
higher than that can be achieved in a single rolling pass.
The roll bonding parameters:
• nature of base metal
• bonding temperature
• rolling pressure
• bonding time
• surface preparation
• layer thickness
• number of layers
• rolling speed
• post and pre heat treatment
• stacking sequence etc.
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Dr.K.Ravi Kumar

6. Accumulative Roll Bonding
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Dr.K.Ravi Kumar

7. Accumulative Roll Bonding
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8. Friction Surface cladding
Cladding takes place due to
(1) the clad material deposits on the
top of the substrate and forms a
non-intermixed layer that contains
the clad material only
(2) Portion of the substrate gets mixed
with the rod to form a layer.
(3) Heat is generated by (1) the
friction between substrate and
rotating rods (2) friction at the
boundary of the tool with the clad
layer on the work piece.
(4) The interface between the tool
and the substrate influences the
thickness of the clad layer.
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Dr.K.Ravi Kumar

9. Friction Surface cladding parameters
• Shape of ring formed at the rod tip and rod diameter
• Axial force, spindle speed and table traverse speed
• Process temperature
• Heat affected zone
• Cooling rate of the material during and after processing
• A wide range of material like aluminium, magnesium and titanium
alloys can be deposited by friction surfacing on alloys and stainless
steels
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Dr.K.Ravi Kumar

10. Laser Cladding
• The coating material can be
pre placed on the substrate
by powder injection or by
wire feeding.
• Laser cladding is a powder
deposition technology
where the powder is blown
through a nozzle on the
work piece surface.
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Dr.K.Ravi Kumar

11. Laser Cladding parameters
• Average power size
• Spot Size
• Wave Length
• Velocity of motion
• Substrate geometry
• Clad powder size
• Clad powder feed rate
• Nozzle Specifications
• Coatings on titanium alloy by laser cladding using SiC, B4C and Y2O3
as clad materials revealed that coatings are reinforced by materials
like NiTi, Cr7C3, CoTi, TiB2, CoTi2, Cr7C3, TiC, TiB, TiC, and Ti5Si3
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Dr.K.Ravi Kumar

12. Microwave cladding
• Charcoal is used as a suspector
material, to make clad powders to
interact with microwaves.
• Experimental were carried in
microwave oven at frequencies around
2.45 GHz and around 900 W.
•
• Time of the cladding process varies
from 180 Seconds to 420 Seconds
based on the cladding thickness.
• The microwave cladding is suitable for
cladding mainly Austenitic steels of
different grades, copper, aluminium
with reinforcements like Nickel,
Tungsten and silicon carbide.
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Dr.K.Ravi Kumar

13. Microwave cladding parameters
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Dr.K.Ravi Kumar

14. Rotary swaging
• Rotary swaging is a precision
forming process normally used
for forming tubes, bars and other
cylindrical components.
• Rotary swaging is used for
producing solid cylindrical, hollow
and solid parts where the axis can
be elongated.
• The rotary swaging process
involves two categories (i)
extrusion of the work piece, by
forcing it into the die (ii) using
two or more dies to hammer the
work piece.
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Dr.K.Ravi Kumar

15. Plasma Surface Cladding
• The plasma beam is
used for melting the
cladding powder and the
substrate.
• Mixture of nickel coated
tungsten carbide
coatings and Nickel-
based alloys were coated
on a steel substrate by a
high temperature
plasma jet exhibited
good boding
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Dr.K.Ravi Kumar

16. Plasma Surface Cladding parameters
• scanning velocity
• Current
• Voltage
• Powder feeding rate
• Plasma gas flow
• Plasma arc length etc.
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Dr.K.Ravi Kumar

17. Explosive bonding
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18. Queries ??
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Dr.K.Ravi Kumar