Surface Roughness Measurement by Ultrasonic Sensing for In-Process Monitoring

Abstract

This paper presents a new surface roughness measurement technique suitable for in-process monitoring in production machining processes. The technique is based on the utilization of focused ultrasonic beams with non-zero incidence angle and measurement of reflected intensities. Fundamental principles and the measurement system developed are described along with experimental results. The tests were conducted to test the sensitivity and robustness of the proposed technique with various milled surfaces and materials. The results show excellent correlations with those obtained by a profilometer. In addition, it is shown that the periodicities of the surface profile corresponding to feed marks can be extracted from the measured ultrasonic signals, thus providing the possibility of profiling. Finally, in-process monitoring of surface roughness during machining is demonstrated with the proposed technique.