The on-line control of Friction Stir Welding processes using ultrasonic test techniques

The Project aims to develop a cost effective and novel Non-Destructive Testing (NDT) technique for the in-process examination of Friction Welds used in the fabrication of welded aluminium structures for the marine, rail, automotive and aerospace industries. The NDT development will be based on high frequency, oblique incident angle, Non-Linear Ultrasonic Testing (NLUT) that will have the capability of detecting early stage 'joint line defects' in the bond region (so called kissing bond) of the weld that has been inherently difficult to inspect because of the poor signal to noise ratio at the size of defects requiring detection against the weld material structure. Failure to detect the joint line defects at an early stage can lead to safety critical component failure with catastrophic consequences. The project will benefit UK industry by enabling the full potential of FSW and LFW to be exploited, this not having been previously possible due to the lack of commercial in-process NDT inspection technology.