PENGARUH VARIASI KUAT ARUS PENGELASAN TIG (TUNGSTEN INERT GAS) TERHADAP SIFAT MEKANIS BAHAN AA 5083 H116 DAN CACAT POROSITAS HASIL UJI RADIOGRAFI
Abstract
Aluminum and chemical composition limits are non-ferrous metals which are widely used in the vehicle, mining and petroleum industries. Aluminum has low density properties, is capable of machining, has relatively high tensile strength, is resistant to corrosion and has a relatively low melting temperature value. In welding aluminum porosity defects are very common, this causes a decrease in the mechanical value of aluminum which is very different when compared to the mechanical value of the raw material itself. The purpose of this study is to determine the effect of porosity defects on the mechanical properties of aluminum.
The testing method used in this study was welding using TIG (Tungsten Inert Gas) of three pieces of AA 5083 H116 material specimens with variations in current strength of 85 A, 90 A, and 95 A. Specimens have dimensions of 300 mm length, 150 mm width, and 3 mm thick. The mechanical test carried out are a tensile test that refers to the ASTM E 8-09 standard, a bend test with the ASTM 190 standard. The fracture from the results of the tensile test will be tested for microstructure against the fractures that occur due to tensile tests.
The results showed that the type of defect in TIG 1 specimens had linear porosity porosity defects on the left side of the weld, clustered porosity on the center of the weld. TIG 2 has linear porosity at the right end of the linear porosity weld at the center of the specimen with a length of 2 cm. TIG 3 TIG 3 specimens are specimens with the highest level of porosity defects between the two TIG 1 and TIG 2 specimens, the results of radiographic tests show the large number of porosity that is spread lengthwise. Tensile test results showed the highest yield strength of TIG 1 specimens with a current of 85 A with a value of 178 MPa, whereas for tensile and strain strength the TIG 2 specimen had a current of 90 A, with a value of 137.61 MPa and a strain value of 8.18%. Test buckling with the highest value is the TIG 3 specimen with a current of 95 A of 142.33 MPa and the lowest value on the TIG 1 specimen with a value of 86.42 MPa.