CFSP - Wichita State University - Two electronic Non-Destructive Evaluation (e-NDE) algorithms for Friction Stir Welding (FSW) have been successfully developed in collaboration with Wichita State University (WSU) and South Dakota School of Mines and Technology (SDSM&T). According to the Probability of Detection (POD) analysis based on the maximum-likelihood method, the e-NDE method gave significantly better detection performances compared to the conventional ultrasonic-phased-array and the X-ray techniques. In addition, from examining a series of cross-sectional macrographs taken from along the weld path, it was found that the e-NDE method tested was sufficiently sensitive to predict volumetric defects even before voids emerged during the welding process. This is accomplished through examining only the feedback signals generated by the process events.
The implementation of e-NDE promotes FSW into a “green-squared” technology. FSW is considered as a “green” welding technology that does not produce any toxic gas or use of filler material. Thus, utilizing e-NDE adds to the “greenness” of FSW by reducing expensive post-weld inspection procedures. Moreover, the development of e-NDE algorithms is the crucial step towards creating an intelligent closed-loop control system for FSW to achieve the highest quality friction stir joints.