Using a novel fixture to study of temperature and applied forces during friction stir welding

Abstract

This paper aims to study the effect of rotation and travel speeds on important parameters such as temperature, and transient and stable axial and longitudinal forces in friction stir welding (FSW) of aluminum AA7075-T6 to find appropriate welding parameters. For simultaneous measurement of axial force, longitudinal force and temperature, a novel fixture is designed and manufactured, which allows force measurement in the friction stir welding (FSW) process without the need to employ expensive equipment. The results show that increasing the travel speed increases both the stable axial and longitudinal forces, whereas increasing the rotation speed decreases both of them. However, the temperature trend upon increment of translation and rotation speeds is contrary to the trend for the axial and longitudinal forces. Furthermore, transient applied forces during the dwell phase are found to be highly fluctuating and much greater compared to the stable forces. Thus, transient forces may be considered as the determining factors for choosing welding.