Joining Aluminum 6061 Alloy Thin Sheets by Friction Stir Spot Welding Method

In this study, the Friction Stir Spot Welding (FSSW) method was employed to join thin AA6061-T4 series aluminum sheets. The AA6061-T4 alloy used in the study has various applications, including aerospace and automotive industries. During the joining process using the FSSW method, emphasis was placed on three parameters: tool rotational speed, pin length, and pin width, considering the advantages of the aluminum alloy used. A total of 12 welding operations were performed with different parameter combinations. The obtained specimens were examined for their mechanical properties, temperature measurement in the weld zone, and microstructure characteristics. Analysis of the results provided information on the shear force and weld zone temperature. The effects of the identified parameters on the AA6061-T4 alloy were presented in the thesis. It was determined that process parameters play a significant role in weld quality. By optimizing the welding parameters such as rotational speed, plunge depth, and appropriate tool geometry for the specimen, weld quality can be significantly improved. Improvements of up to 200% were achieved through the optimization of inadequate temperature and rpm parameters. While noticeable differences in tool geometry were observed at low heat inputs, the effect of tool geometry decreased at high heat inputs. However, significant differences were not observed in the temperature tests conducted. The obtained results suggest that they contribute to the resolution of potential issues arising from the joining of thin AA6061-T4 sheets. This can lead to minimizing problems and providing contributions to the industry in terms of cost, quality, and other aspects.