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A. K. Choudhary and R. Jain
resulting in partially recrystallized grains. Here the grains undergo a considerable
change of shape and its elongation is followed by bending during the FSW process
[30]. Adjacent to TMAZ is HAZ formed due to prolonged heating and cooling cycle
leading to the generation of coarser grains as the time required for cooling is high
[8].
2.2.3 Advantages of FSW
1. Solidification defects are eliminated in FSW as it does not involve melting and
re-solidification [31].
2. For low-density material, the tool wear is almost negligible resulting in lower
tooling cost.
3. FSW is an energy-efficient process as it consumes about 2.5% of the energy of
laser/Electron beam welding [14].
4. Dynamic recrystallization leads to fine equiaxed grain resulting in higher
mechanical and metallurgical properties of the weld. With the proper choice
of input process parameters, FSW can result in 70–90% weld efficiency.
5. It is green technology because of the absence of the generation of any toxic
gases/fumes.
6. Shielding gases are not required.
7. No filler materials are required as welding takes place in solid-state.
8. It can successfully weld dissimilar metals i.e. steel and aluminium, magnesium,
and aluminum.
9. FSW results in a good weld appearance thus it eliminates the need for post-weld
machining.
2.2.4 Disadvantages of FSW
1. An exit hole is generated at the end of the process.
2. FSW tool undergoes severe stress and high-temperature exposure. This leads to
tool wear and loss of strength resulting in low performance of the tool for high
strength material such as steel, titanium alloys, etc. [32].
3. A very high degree of reactive force is generated during the plunging operation
and hence requires a machine with high stiffness.
A. K. Choudhary and R. Jain
resulting in partially recrystallized grains. Here the grains undergo a considerable
change of shape and its elongation is followed by bending during the FSW process
[30]. Adjacent to TMAZ is HAZ formed due to prolonged heating and cooling cycle
leading to the generation of coarser grains as the time required for cooling is high
[8].
2.2.3 Advantages of FSW
1. Solidification defects are eliminated in FSW as it does not involve melting and
re-solidification [31].
2. For low-density material, the tool wear is almost negligible resulting in lower
tooling cost.
3. FSW is an energy-efficient process as it consumes about 2.5% of the energy of
laser/Electron beam welding [14].
4. Dynamic recrystallization leads to fine equiaxed grain resulting in higher
mechanical and metallurgical properties of the weld. With the proper choice
of input process parameters, FSW can result in 70–90% weld efficiency.
5. It is green technology because of the absence of the generation of any toxic
gases/fumes.
6. Shielding gases are not required.
7. No filler materials are required as welding takes place in solid-state.
8. It can successfully weld dissimilar metals i.e. steel and aluminium, magnesium,
and aluminum.
9. FSW results in a good weld appearance thus it eliminates the need for post-weld
machining.
2.2.4 Disadvantages of FSW
1. An exit hole is generated at the end of the process.
2. FSW tool undergoes severe stress and high-temperature exposure. This leads to
tool wear and loss of strength resulting in low performance of the tool for high
strength material such as steel, titanium alloys, etc. [32].
3. A very high degree of reactive force is generated during the plunging operation
and hence requires a machine with high stiffness.