RANCANG BANGUN ANTENA MIKROSTRIP SIERPINSKI GASKET ARRAY PENGUAT MODEM GSM PADA KENDARAAN MOBIL PRIBADI
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. Friction stir welding (FSW) is a challenging alternative
for joining aluminum alloy. In FSW, process occur in the solid state (solid
state joining). In this research, some attempts were carried out to find the
best quality of welding, in term of mechanical properties and microstructure. Tool
rotation speed was varied at 780, 980, 1120 rpm. Whereas, feed rate used was
keep constantly at 15 mm/min. The material to be welded is a- 4.0 mm thick
aluminum AA 1100 strips. Result showed that the highest strength obtained is
56.528 MPa at 1120 rpm and the lowest strength obtained is 38.472 MPa at 980
rpm. 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.
Penulis: M. Yasin Anwar, Dodi
Setiabudi, Widya Cahyadi
Kode Jurnal: jptmesindd160321
