Effect of Temperature, Force, and Vibration on Fatigue Strength of Friction Stir-Welded AA7075 Aluminum Alloy Joints

In this study, the AA7075 alloy pairs were welded by friction stir welding method by using conical- and triangular-type stirrer pins. Welding forces and moments, vibration, and temperature values have been measured during the jointing depending on the welding parameters. Finally, microstructures were examined and mechanical tests were carried out. Results obtained from the experiments revealed that at low spindle speed and welding feed rates, the temperatures formed on the surface of the alloy pair were high, the vibrations were low, and the welding force and moments were partially high. When the microstructures of the welded areas are examined, it was determined that the conical mixing pin has a better microstructure than the triangular mixing pin. In addition, it was determined that the mechanical properties of welded joints having a good microstructure were quite good. As a result, it was observed that forces during welding, temperature of welding, and vibration values have an effect on microstructure and mechanical properties.

Automated summary

The study on friction stir welding of AA7075 alloy pairs using conical- and triangular-type stirrer pins showed that low spindle speed and welding feed rates resulted in high surface temperatures, low vibrations, and partially high welding forces and moments. Comparing the microstructures of welded areas, it was found that the conical mixing pin produced better microstructure than the triangular mixing pin. Furthermore, it was observed that welded joints with good microstructure exhibited quite good mechanical properties, indicating that welding forces, temperature, and vibration values have an impact on microstructure and mechanical properties.