Product Code: JLA_5_2_17

Authors:
Y‐L. Mao
G. Kinsman
W. W. Duley
Physics Department, University of Waterloo, Waterloo, Ontario, Canada, N2L 3G1

Real‐time fast Fourier transform (FFT) analysis of acoustic emission has been developed for monitoring laser welding processes. Significant differences in acoustic emission have been observed in conduction and keyhole processing regimes. The amplitude fluctuation of acoustic emission becomes intensified in the transition from conduction welding to keyhole welding. The integrated FFT power spectrum emission has been correlated to laser power, welding speed, and focusing parameters. These results suggest a simple way of monitoring the welding process. A simplified physical model has been developed to explain the fluctuation frequency. The predictions of this model are found to be in good agreement with experimental data.