Experimental detection of micro-cracks during the CO₂ laser machining of ceramics

This paper describes experimental work in which the use of acoustic emission (AE) techniques are used to provide an on-line indication of cut quality during the CO₂ laser machining process. Two common engineering ceramics, namely Kyocera and Macor, are investigated for both continuous wave (CW) and pulse mode (PM) cutting. Results are presented that attempt to classify the quality of finished cut with respect to the AE activity per event ratio produced during testing. The paper concludes that a definite correlation exists between the quality of the cut surface and the amount of acoustic energy emitted under certain cutting conditions. © 2001 OPA (Overseas Publishers Association) N.V.