Welding is a fabrication or sculptural process that joins materials, usually metals or thermoplastics, by causing fusion, which is distinct from lower temperature metal-joining techniques such as
brazing and soldering,
which do not melt the base
metal.
UNIT-V FMM.HYDRAULIC TURBINE - Construction and working
FRICTION AND EXPLOSION WELDING
1. TOPIC : FRICTION AND EXPLOSION
WELDING
GOVERNMENT ENGINEERING COLLEGE BHARUCH
SUBJECT : MANUFACTURING PROCESS - II
DIV : MECHANICAL B (SEM - IV)
PREPARED BY :
RATHWA RAHUL - 160140119095
RAVAL KRUNAL - 160140119096
SAKHIWALA MAHIR -160140119098
SARDHARA KISHAN -160140119099
2. WELDING
Welding is a fabrication or sculptural process that joins
materials, usually metals or thermoplastics, by causing
fusion, which is distinct from lower temperature metal-
joining techniques such as
brazing and soldering,
which do not melt the base
metal.
4. SOLID STATE WELDING:
Solid State Welding is a welding process, in which two
work pieces are joined under a pressure providing an
intimate contact between them and at a temperature
essentially below the melting point of the parent material.
Forge Welding (FOW)
Cold Welding (CW)
Friction Welding (FRW)
Explosive Welding (EXW)
Diffusion Welding (DFW)
Ultrasonic Welding (USW)
5. Friction Welding (FRW):
PRINCIPLES:
Friction welding (FRW) is a solid state welding process .In
Friction welding process heat is required to produce a joint
Between two objects. One of the parts to be joined is rotated
At a high speed around 3000 revolutions per minute (rpm)
And the other part is axially aligned with the second one and
Pressed tightly against it. The friction between the two parts
Raises the temperature of both ends, then the rotation of the
Part is stopped abruptly and the pressure on the fixed part is
Increased so that the joining takes place.
6. Material that can be welded in Friction
Welding:
Carbon steels ,
Alloy steels
tool and die Steels, stainless steels
Aluminium alloys, copper alloys
Magnesium alloys, nickel alloys
Titanium alloys can be
Joined by friction welding.
7. Sequence of operations in the friction
welding process:
Fig. (a) Left part is rotated at high speed
Fig. (b) Right part is brought into contact under an axial
force
Fig. (c) Axial force increased; flash begins to form
Fig. (d) Left part stops rotation. Weld is completed. Flash
can beremoved by machining or grinding.
8. ANAYLSIS:
Shape of fusion zone in friction welding, as a function of
force applied and
rotational speed:
9. Advantages of Friction Welding:
Simplicity of operation and simple equipment.
Less time requirement.
Low Surface impurities and oxide films.
Compare to resistance butt welding produces improved
welds at higher speed and lower cost, less electric
current is required.
Heat affected zone is small as compare to conventional
flash welding.
Less shortening of the component, as compared to that in
flash or butt welding.
There is no flux, gas, filler metal.
10. Disadvantages of Friction Welding:
Process is restricted to flat and angular butt welds.
Use only for joining small parts.
In case of tube welding process becomes
complicated.
In case of high carbon steels it is difficult to remove
flash.
It require heavy rigid machine due to high Thrust
pressure.
11. Applications:
Automobile: Bimetallic engine valve, universal joint yoke, gear hub.
Aerospace: Turbine blade joining, seamless joining etc.
Consumer: Hand tools, sports equipment
Industrial: Spindles, tapers, tools Military
Medical: Stainless steel joining of containers
Marine: Shipping Industry
Mining/Drilling: Twist drill etc.
Hydraulic equipments
13. EXPLOSION WELDING
Explosion welding was developed relatively recently,
decades after world war-II.
This process is most commonly utilized to cladcarbon steel
with the corrosion-resistant material e.g. stainless steel,
nickel alloy, titanium, zirconium, etc.
SSW process in which rapid coalescence
of two metallic surfaces is caused by the energy of a
detonated explosive.
The process is quite dangerous
and should be performed under
some experts in specially designed
chambers.
14. Explosive Welding is a Solid State Welding process, in
which welded parts (plates) are metallurgical bonded as a
result of oblique impact pressure exerted on them by a
controlled detonation of an explosive charge.
Dissimilar metals may be joined by Explosive Welding:
Copper to steel
Nickel to steel
Aluminium to steel
Tungsten to steel
Titanium to steel
Copper to aluminium.
15. Cross – sections of explosion welded
joints:
Fig. a) Titanium (top) on lowcarbon steel Fig. b)iron nickel based on low carbon
16. ADVANTAGES:
• Dissimilar material joining is possible through this process.
E.g., Al to steel, Cu to steel, Tungsten to steel, etc.
• No filler metal used , no external heat applied.
• Bonding is metallurgical, combined with mechanical
interlocking that results from a rippled or wavy interface
between the metals.
APPLICATIONS:
• Joining of pipes and tubes
• Attaching cooling fins
• Major app. In pressure vessels
17. DISADVANTAGES:
Brittle materials( Low impact toughness) can not be
welded.
Extensive knowledge of explosives is needed before
the procedure may be attempted safely.
The geometries must be simple.