Development of a thermocouple sensor using tool coating and its substrate to measure metal turning temperatures

Abstract

The power consumed in metal cutting is largely converted into heat. Several methods to develop thermal sensors for observing the temperature in cutting tool have been attempted. However, the developed thermal sensors for machining process are having difficulties to reliably provide high spatial and temporal resolutions for monitoring the dynamic thermal phenomena at the tool-workpiece interface. In this paper, a novel sensor using tool coating and its substrate is developed as a thermocouple to measure cutting temperature during turning. Firstly, the sequence of fabricating the novel coating-substrate thermocouple is proposed. Calibration setups to measure cutting temperature are then presented. Finally, the cutting experiments are carried out under different cutting conditions for 1,045 steel. The temperature data obtained during cutting experiments demonstrate the functionality of the developed novel sensor with coated cutting tools. This cutting temperature measurement approach can obtain transient tool internal temperature data reliably from a very close distance to the tool-workpiece interface, which will be very significant for the in-process control of machining operations.