74
A. K. Choudhary and R. Jain
Carlone et al. [145] investigated dissimilar FSW of 2 mm thick AA2024-T3 rolled
sheet with pure Cu10100 at 2° tilt angle. The tool was made up of Cr–Mo steel. Experiments were carried out at 1000 rpm and 80 mm/min. Tool offset towards aluminum
in the advancing side was kept at 1.3 mm for efficient material mixing. Microstructural examination showed that the weld nugget zone comprised of a combination of
the recrystallized aluminum matrix along with twinned and deformed copper scrap.
Small copper dispersed within Al matrix was also detected. It resulted in the formation of intermetallic compounds like AlCu, Al 2 Cu, and Al 3 Cu 4 . These intermetallics
significantly change hardness distribution within the weld zones.
Bakhtiari et al. [146] studied dissimilar FSW of 4 mm thick 5754-H114 aluminum
alloy with commercially pure copper in butt configuration with H13 threaded tapered
tool. The aluminum plate was positioned on the advancing side with 1 mm offset
for better material flow and material mixing. FSW was carried out at a different
input parameter to get optimized results. Micrograph revealed the formation of intermetallic compounds ie. Al 4 Cu 9 and Al 2 Cu within FSW joints. Good results were
found at an optimized rotational and welding speed of 1000 rpm with 100 mm/min.
A maximum weld efficiency of 84% was achieved with a weld strength of 219 MPa.
The peak value of microhardness was about 120 HV at the SZ.
Akinlabi [147] investigated the effect of the tool shoulder diameter on dissimilar
friction stir weld of AA5754 with C11000 copper. H13 tool steel with 2° tilt was
employed for welding. The shoulder diameter varied from 15, 18, and 25 mm for
rotational speed between 600 and 1200 rpm and the welding speed between 50 and
300 mm/min. The optimized weld parameter was obtained with 18 mm shoulder
diameter and at 950 rpm and 50 mm/min. A joint efficiency of 86% was obtained for
this parameter. Average Vickers microhardness was obtained at 95HV towards the
copper side. Al 4 Cu 9 and Al 2 Cu were the intermetallic reported that were detected at
the weld interface.
2.8.2.2 FSW of Aluminum and Magnesium
Dissimilar FSW of Al with Mg is investigated as it has gained a huge interest due
to lightweight of magnesium which later resulted in a reduction of weight of the
entire welded components. These dissimilar FSW joined components are applicable
to mostly automobile and aerospace parts to have a weight reduction factor [148].
Vahid Firouzdor [149] FSWed AA6061 with AZ31 to study the effect of process
parameters on joint properties of the weld. During dissimilar FSW, precipitates of
Al 3 Mg 2 and Al 12 Mg 17 were found at the stir zone resulting in a reduction of joint
strength. Magnesium was kept on the retreating side with tool offset to produce the
defect-free weld. As magnesium is a softer material, its alloy resulted in superior
flow behavior and continue to stir behind the tool followed by mixing with Al alloy.
At slower welding speed and with aluminum on AS, higher heat is generated. While
putting Mg, on the AS at slow welding speed can enhance the weld strength by
decreasing the heat input.
A. K. Choudhary and R. Jain
Carlone et al. [145] investigated dissimilar FSW of 2 mm thick AA2024-T3 rolled
sheet with pure Cu10100 at 2° tilt angle. The tool was made up of Cr–Mo steel. Experiments were carried out at 1000 rpm and 80 mm/min. Tool offset towards aluminum
in the advancing side was kept at 1.3 mm for efficient material mixing. Microstructural examination showed that the weld nugget zone comprised of a combination of
the recrystallized aluminum matrix along with twinned and deformed copper scrap.
Small copper dispersed within Al matrix was also detected. It resulted in the formation of intermetallic compounds like AlCu, Al 2 Cu, and Al 3 Cu 4 . These intermetallics
significantly change hardness distribution within the weld zones.
Bakhtiari et al. [146] studied dissimilar FSW of 4 mm thick 5754-H114 aluminum
alloy with commercially pure copper in butt configuration with H13 threaded tapered
tool. The aluminum plate was positioned on the advancing side with 1 mm offset
for better material flow and material mixing. FSW was carried out at a different
input parameter to get optimized results. Micrograph revealed the formation of intermetallic compounds ie. Al 4 Cu 9 and Al 2 Cu within FSW joints. Good results were
found at an optimized rotational and welding speed of 1000 rpm with 100 mm/min.
A maximum weld efficiency of 84% was achieved with a weld strength of 219 MPa.
The peak value of microhardness was about 120 HV at the SZ.
Akinlabi [147] investigated the effect of the tool shoulder diameter on dissimilar
friction stir weld of AA5754 with C11000 copper. H13 tool steel with 2° tilt was
employed for welding. The shoulder diameter varied from 15, 18, and 25 mm for
rotational speed between 600 and 1200 rpm and the welding speed between 50 and
300 mm/min. The optimized weld parameter was obtained with 18 mm shoulder
diameter and at 950 rpm and 50 mm/min. A joint efficiency of 86% was obtained for
this parameter. Average Vickers microhardness was obtained at 95HV towards the
copper side. Al 4 Cu 9 and Al 2 Cu were the intermetallic reported that were detected at
the weld interface.
2.8.2.2 FSW of Aluminum and Magnesium
Dissimilar FSW of Al with Mg is investigated as it has gained a huge interest due
to lightweight of magnesium which later resulted in a reduction of weight of the
entire welded components. These dissimilar FSW joined components are applicable
to mostly automobile and aerospace parts to have a weight reduction factor [148].
Vahid Firouzdor [149] FSWed AA6061 with AZ31 to study the effect of process
parameters on joint properties of the weld. During dissimilar FSW, precipitates of
Al 3 Mg 2 and Al 12 Mg 17 were found at the stir zone resulting in a reduction of joint
strength. Magnesium was kept on the retreating side with tool offset to produce the
defect-free weld. As magnesium is a softer material, its alloy resulted in superior
flow behavior and continue to stir behind the tool followed by mixing with Al alloy.
At slower welding speed and with aluminum on AS, higher heat is generated. While
putting Mg, on the AS at slow welding speed can enhance the weld strength by
decreasing the heat input.