ASSESSMENT OF TOOL WEAR IN MILLING USING ACOUSTIC-EMISSION DETECTED BY A FIBER OPTIC INTERFEROMETER

Acoustic emission (AE) has previously been shown to be a useful techni que in monitoring the state of wear of cutting tools. The piezo-electr ic transducers conventionally used for AE detection are contacting dev ices with a limited bandwidth. This paper describes the use of a robus t fiber optic interferometer for the in-process measurement of AE duri ng the face milling of annealed En24 steel to provide tool wear inform ation via analysis of the rms AE signal. The interferometer displayed an improved diagnostic capability over a conventional piezoelectric se nsor due to its advantages of being non-contacting, broadband with a f lat frequency response to displacement, and providing absolute calibra tion.