QUANTITATIVE MEASUREMENT OF TEMPERATURES ON DIAMOND-COATED TOOLS DURING MACHINING

A new measuring technique is shown which can determine the absolute te mperatures at the rake face of diamond-coated inserts during dry turni ng. Cutting temperatures, which can be measured by this infrared therm ographic system, varied with the workpiece material, aluminium (AlZnMg Cu1.5) or titanium (TiAl6V4) alloys, and the cutting conditions. The m easured temperature distribution at the chip bottom side immediately r eaches a steady state value (testing time is 0.1 s) and so it is also possible to transmit the measured temperatures to other machining oper ations, like milling and drilling. Good agreement exists between the m easured temperatures and the corresponding tool wear values. To verify the repeatable calibration results, two methods are used and describe d to measure the spectral directional emissivity of the chip bottom si de. The difficulties, problems and the sources of error associated wit h the calibration method are pointed out. This temperature measuring s ystem can be used for determining the machinability of various workpie ce materials with new cutting tools. Additionally, it will be an impor tant tool to better understand tool wear mechanisms.