Friction Stir Spot Welding of SSM 6061 Aluminium Alloy

Abstract

The research aims to study friction stir spot welding (FSSW) of semi-solid metal 6061 aluminum alloy. For parameters in experimental such as rotation speed at 380, 760, 1240 and 2500 rpm, holding time 30, 45 and 60 second and depth of plunge 2.4 millimeter. The experiments show that the physical characteristics of the specimen from FSSW are complete; there was no distortion or cracking in of the specimen. Which the specimens after FSSW process are likely to produce a very good weld. The maximum shear strength average was 251.5 MPa from rotational speed of 1240 rpm and holding time 30 second. On the other hand, from rotational speed of 2500 rpm and holding time 60 second gives minimum shear strength average was 132.07 MPa respectively. The results shown that a have increase hardness in stir zone, when maximum hardness was 59.95 HV and hardness of base materials was 54.38 HV. Characteristics of microstructure in the stir zone are changed in a favorable direction, as a result mechanical properties of the specimen well. The analysis of the data retrieval shears strength by statistical confidence level of 95 percent shows that the coefficient of determination (R²) was 98.42 percent, which comes from controllable and coefficient of determination was 1.58 percent from uncontrollable in experimental.