Plasma arc and friction welding

1. MANUFACTURING TECHNOLOGY – I
CRAFTED BY:
RAMESH KUMAR A
ASSISTANT PROFESSOR
SONA COLLEGE OF TECHNOLOGY
SALEM
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2. PLASMA ARC WELDING
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3. PLASMA ARC WELDING
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4. PLASMA ARC WELDING…
 Non-consumable tungsten electrode
 Transferred arc – workpiece in positive and electrode in negative
 Non-transferred arc – between electrode in negative and water-
cooled constricting nozzle in positive
 Temperatures between 8000 to 25000°C depend upon plasma gas
 Such temperatures are attained by the constriction of the arc, by
forcing the arc through a water cooled constricting nozzle at the
bottom end of the inner gas cup
 Thereby reducing the arc diameter and consequently increasing current
density, which results in increase in pressure, temperature and heat
intensity of the arc
 Two inert gas – plasma and shield
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5. PLASMA ARC WELDING…
 DC power source – 70V
 Currents – 50 to 350 amps
 Voltage – 27 to 30V
 DCSP except Al
 Argon
 He or mixture of He and Ar
 Ferrous and non-ferrous metals
 Upto 6mm
 Radiators, exhaust manifolds, air ducting, metal mesh, fine wires, etc.,
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6. PLASMA ARC WELDING…
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7. FRICTION WELDING
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8. FRICTION WELDING
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9. FRICTION WELDING…
 Mechanically induced sliding
motion between the two rubbing
surfaces
 Temperatures developed are
below the melting point of the
metals being welded but high
enough to create plastic flow and
inter-molecular welding
 Under pressure during welding
 Rotational speed – 1500 rpm
(carbon steels) to 3800 rpm
(aluminum)
 Contact pressure – 280 kg/cm2
(Al) to 525 kg/cm2 (steel)
 Welding time – 15s
 Materials – Al and alloys, brass,
bronze, stainless steel, nickel
alloys, carbon steels etc.,
 Applications:
 Automobile industries
 Bimetallic shafts
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10. FRICTION WELDING…
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