Effect of Process Parameters on Microstructural and Mechanical Properties of Friction Stir Welded 2219 Aluminium Alloys

摘要

The effect of process parameters on the mechanical and microstructural properties of friction stir welded AA 2219 alloy is elucidated in this study. Tool rotational speed, tool traversal speed, vertical force and pin profile were considered as process parameters in the investigation. Based on the conclusion that the tool pin profile is the most influential parameter in deciding the weld strength, the microstructural changes with various pin profiles were examined. Microhardness profile was taken as the preliminary informative source for microstructural changes. Optical microscopy and scanning electron microscopy (SEM) was used for identifying the microstructural changes and behavior of strengthening precipitates. Energy dispersive spectroscopy (EDS) was conducted to identify the precipitates and their distribution. Distribution and dissolution of precipitates were distinct for different tool pin profile which is symptomatic for the variation in mechanical properties.