Online Monitoring of Laser Welding Process by Ultrasonic Testing
G.L. Goswami, R. Galun, G. Neuse and B.L. Mordike
Ultrasonic waves reflect from interfaces separating materials with different acoustic impedance. This is the basic principal of flaw detection using ultrasonic testing. These testing are mostly static. Experiments have been done to explore the possibilities of using this technique for online monitoring of laser welding process. Ultrasonic signals reflected from the solid – liquid interface, observed online during laser surface melting of a mild steel plate indicate that this technique can be used for online monitoring of depth of penetration and weld bead height during laser welding process. Additionally rate of liquification and solidification can also be obtained from the rate of movement of the position of the ultrasonic signals reflected from the solid – liquid interface during laser welding process.