• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.930-933
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• 2000

In this report experimental ultrasonic machine system has been fabricated and experimental machining has been performed using glass as a workpiece material. As grit size increases, material removal rate(MRR) was observed to be increased at decreased applied tool pressure on the workpiece, however at the higher applied pressure above $2-4\;kg/cm^2$ for smaller grit size, the MRR was not increased. Also better surface roughness was obtained for smaller grit size. Microchipping was observed from the microscopic examination and the pattern is similar to the iso-stress field where cracking is considered to be initiated near the surface.

• Journal of the Korean Society for Nondestructive Testing
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• v.11 no.1
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• pp.31-37
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• 1991

Acoustic emission(AE) signals detected during metal cutting were applied as the experimental test to sensing tool wear and chipping on the NC vertical milling machine. The in-process detection of cutting tool wear including chipping, cracking and fracture has been investigated by means of AE in spite of vibration or noise through intermittent metal cutting, then the following results were obtained 1) When the tool wear is increased suddenly, or the amplitude of AE signals changes largely, it indicates chipping or breaking of the insert tip. 2) It was confirmed that AE signal is highly sensitive to the cutting speed and tool wear. 3) At the early period of cutting, the wear were large and RMS value increased highly by the influence of minute chipping and cracking, etc. Therefore, the above situations should be considered for the time when the tool would be changed.