SIFAT MEKANIK DAN STRUKTUR MIKRO ALUMINIUM AA1100 HASIL PENGELASAN FRICTION STIR WELDING DENGAN VARIASI FEED RATE

Aluminum and aluminum alloys have properties that are less well when comparedto steel, such as specific heat and has a high conductivity. They are also easily oxidizedand 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 aluminumwelding process. FSW is the working principle of utilizing the friction of the rotatingworkpiece with a stationary workpiece another so that the resulting heat and the heatcan melt the workpiece is stationary and connected to one end. FSW welding process tooccur at the solvus temperature, so there is no reduction in strength due to aging and dissolutionof the precipitate over coherent. Theresearch aim is to find the best mechanicalproperties, i.e strength and thoughness by varying feed rate. Observations onto microstructuresof welding area were also carried out in this research. Feed rate was varied at7,3, 13, 24mm/mnt. Whereas,tool rotation used was keep constantly at 1200rpm. The materialto be welded is a 4.0 mm thick aluminum AA1100 strips. Result showed that thehighest strength obtained is 61,53 MPa at 24mm/mnt and the lowest strength obtained is49,44 MPa at 7,3 mm/mnt.Wormholes and the lack of penetration defects are the mainthings that reduce the tensile strength. From micro observations known on the grainsshape of the stir zone, FeAl3 particles is spread more evenly in matrix of Al due to thestir process during the welding process. Hardness tests showed that the weld metal issofter than the base metal