2. Cladding
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• 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.
3. Claddin
g
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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4. Roll Bonding
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• 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.
5. Roll bonding
parameters
• Suitable for ductile materials
• A maximum of 50 % reduction in thicknessor 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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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
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9. Friction Surface cladding
parameters
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• 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
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
technolog
y where the powder is
blown through a nozzle
on the work piece
surface.
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11. Laser Cladding parameters
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• 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
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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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. 14
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
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