SIFAT MEKANIK DAN STRUKTUR MIKRO ALUMINIUM AA1100 HASIL PENGELASAN FRICTION STIR WELDING DENGAN VARIASI FEED RATE
Abstract
Aluminum and aluminum alloys have properties that are less well when compared
to steel, such as specific heat and has a high conductivity. They are also easily oxidized
and form an aluminum oxide Al2O3 which have a high melting point. Consequently,
when they are welded the fusion between base and weld metal will be blocked. Moreover,
if the cooling process is too fast it will form a smooth cavity ex-pouch of hydrogen.
FSW (Friction Stir Welding) is one solution that can be used as an alternative to aluminum
welding process. FSW is the working principle of utilizing the friction of the rotating
workpiece with a stationary workpiece another so that the resulting heat and the heat
can melt the workpiece is stationary and connected to one end. FSW welding process to
occur at the solvus temperature, so there is no reduction in strength due to aging and dissolution
of the precipitate over coherent. Theresearch aim is to find the best mechanical
properties, i.e strength and thoughness by varying feed rate. Observations onto microstructures
of welding area were also carried out in this research. Feed rate was varied at
7,3, 13, 24mm/mnt. Whereas,tool rotation used was keep constantly at 1200rpm. The material
to be welded is a 4.0 mm thick aluminum AA1100 strips. Result showed that the
highest strength obtained is 61,53 MPa at 24mm/mnt and the lowest strength obtained is
49,44 MPa at 7,3 mm/mnt.Wormholes and the lack of penetration defects are the main
things that reduce the tensile strength. From micro observations known on the grains
shape of the stir zone, FeAl3 particles is spread more evenly in matrix of Al due to the
stir process during the welding process. Hardness tests showed that the weld metal is
softer than the base metal.
to steel, such as specific heat and has a high conductivity. They are also easily oxidized
and form an aluminum oxide Al2O3 which have a high melting point. Consequently,
when they are welded the fusion between base and weld metal will be blocked. Moreover,
if the cooling process is too fast it will form a smooth cavity ex-pouch of hydrogen.
FSW (Friction Stir Welding) is one solution that can be used as an alternative to aluminum
welding process. FSW is the working principle of utilizing the friction of the rotating
workpiece with a stationary workpiece another so that the resulting heat and the heat
can melt the workpiece is stationary and connected to one end. FSW welding process to
occur at the solvus temperature, so there is no reduction in strength due to aging and dissolution
of the precipitate over coherent. Theresearch aim is to find the best mechanical
properties, i.e strength and thoughness by varying feed rate. Observations onto microstructures
of welding area were also carried out in this research. Feed rate was varied at
7,3, 13, 24mm/mnt. Whereas,tool rotation used was keep constantly at 1200rpm. The material
to be welded is a 4.0 mm thick aluminum AA1100 strips. Result showed that the
highest strength obtained is 61,53 MPa at 24mm/mnt and the lowest strength obtained is
49,44 MPa at 7,3 mm/mnt.Wormholes and the lack of penetration defects are the main
things that reduce the tensile strength. From micro observations known on the grains
shape of the stir zone, FeAl3 particles is spread more evenly in matrix of Al due to the
stir process during the welding process. Hardness tests showed that the weld metal is
softer than the base metal.