Studi Sifat Mekanis dan Mikrostruktur Sambungan Las Aluminium 6061 pada Chasis Mobil Halisungsung Horas USU Menggunakan SMAW, MIG dan TIG

Abstract

Today Technological improvements are experiencing a rapid development, especially in the field of welding. SMAW (Shielded Metal Arc Welding), MIG (Metal Inert Gas) and TIG (Tungsten Inert Gas) were wellding methods that used in this research. Which to determine the defects formed, mechanical properties and microstructural appear- ance of the welding results of Aluminium 6061 using the same parameters, namely a current strength of 110 A, a gas flow rate of 121/s and the same lug angle as the "HALISUNGSUNG HORAS USU" car chassis application. The tests that had the highest average tensile strength value was MIG welding, which was 195.31 MPa. while the lowest was SMAW welding, which was 130.61 MPa. The highest average hardness test value is for MIG welding with an average value of 63.8 VHN in the HAZ area and the lowest for SMAW welding is 58.2 VHN. On the visual display of welding surface defects using the Penetrant Test, the lowest defect results are obtained in MIG welding are 2 types of welding defects. The best visual appearance of the microstruc- ture is in MIG welding because there is no porosity and the appearance of finer grains.