Nondestructive control of the electron beam (EB) welding process by means of acoustic emission (AE)

Process control by means of acoustic emission is successfully applied during EB-welding. Defects can be detected and localised. Different localisation algorithms are presented. Especially the localisation method independent of sound velocity is discussed thoroughly. AE-source localisation depends on the measured arrival time intervals strongly. Therefore different methods to estimate these differences like cross correlation or the use of trigger levels were investigated.