Perbandingan Bentuk Profil Pin Segitiga Segiempat dan Lingkaran pada Hasil Pengelasan Friction Stir Welding dengan Preheating 200ºc pada Material AA-5056 terhadap Perubahan Sifat Fisis dan Mekanis

Preheating is heat given to metals to be welded to obtain and maintain preheat temperature. Preheating in this process aims to provide heat to the work piece just before the welding process is done so that the material becomes softer so that it can increase the effectiveness of the Friction stir welding (FSW) process. This study aims to determine the effect of the preheating temperature on physical and mechanical properties at AA 5056 using a friction stir welding method with the shape of a circle, triangle and quadrilateral pin profile. The AA 5056 plate used in this study measures 150 x 50 x 3 mm with 1500 rpm and 60 mm / minute feed rate. From the results of the study it can be concluded that the shape of the pin profile can influence the physical and mechanical properties of the test. The highest value of tensile stress is in the triangular pin profile of 91.803 MPa, while the highest strain value is found in the circle pin profile of 21.88%. The highest hardness value is located in the weld area (Weld Nugget) of 33 VHN, Haz area of 38 VHN, 37 VHN base metal. From the observation of the micro structure above, there are two areas, namely dark and bright areas. The