Studies on Non-Destructive Evaluation of Friction Stir Weld Discontinuities with Probability of Detection

Abstract

Friction stir welding(FSW) is a solid-state metal joining process which is currently being considered for joining of aerospace components. The zones associated with FSW are distinctly different from the fusion weld and their properties also vary. Further, the discontinuities and defects encountered are unique in nature. As most aerospace components are designed with limited margin, the identification of the Friction stir weld defects and discontinuities, and their effect on the performance pose continuous challenges for the quality assessment. Thus, detection, location and characterization of different types of defects encountered in FSW, along with Probability of Detection (POD) of those discontinuities in aerospace friction stir welded components with its varying metallurgical characteristics are the primary objectives of the investigations taken up. The focus has been on capability of different NDE tools in detecting and evaluating different types of defects in FSW joints in the Aluminum alloy AA2219 and to establish the outcome through POD concept.