Detection of thermal damage using acoustic emission underdifferent grinding conditions

Grinding is the last manufacturing process used in cases where adequate measurement accuracy and surface quality cannot be obtained with other machining methods. This thesis presents the detection of burn damage during grinding using acoustic emission (AE) activities. The burn effect was determined using the instantaneous energy and signal phase derived from the continuous wavelet transform (CWT) under different grinding operations (e.g. a higher cutting speed, a larger infeed and a smaller amount of dressing depth). Experimental results showed that the instantaneous energy of the AE signal obtained from the burnt case exhibits a decrease compared to that of the undamaged condition. Similarly, the AE signal for the burnt yields a lesser amount of phase deviation compared to the intact case. Continuous Wavelet Transform results were compared with those of the Hilbert-Huang transform and found that both methods yield very similar results.