Acoustic Emission And Its Application To Laser Spot Welding

A simple method for noncontact measuring acoustic emission generated during laser welding of steel X5CrNi18 9 and pure aluminium is presented. Laser beam quality is kept constant to insure that AE signal is just affected by the weld process. It will be shown that measuring in noncontact manner depends on formation of plasma, otherwise AE is generated due to backscattered laser radiation, which heat the fixture of the AE sensor.