CHARACTERISTICS OF SOUND GENERATED IN Q-SWITCHED YAG LASER MACHINING

Sound generated in Q-switched YAG laser machining is monitored by a microphone with a sensing range of 4 Hz to 100 kHz. The sound frequency is in a range of 1 kHz (Q-switching frequency) to higher than 100 kHz and the sound spectrum takes a maximum at 40 - 50 kHz for all materials used in the experiments. There is a linear relationship between volumetric material removal rate and generated sound pressure level in the steady state machining such as groove-making. The machining process can be monitored by a microphone for audible sound in the actual monitoring system.