Towards real-time quantitative monitoring and control of weld pool dimensions using phased array ultrasonics

While ultrasonic NDT of welded joints is well understood and commercially undertaken at the end of the fabrication timeline, significant commercial benefits can be realised through the adoption of novel in-process inspection and monitoring techniques. This paper shows the use of phased array ultrasonics to monitor and analyse the molten weld pool live during weld deposition. The received ultrasonic signals are shown to contain information related to key physical transitions occurring within the welding process, namely the melting and solidification of the weldment. This preliminary work unlocks the potential for real-time monitoring and control of the welding process. The information stored within the ultrasonic signals can be directly related to quantitative information about the welding process providing means for anticipation of defect occurrence and preventative control.