SIMULTANEOUS MEASUREMENT OF THE THERMAL AND TRIBOLOGICAL EFFECTS OF CUTTING FLUID

The use of cutting fluids in industrial machining is widespread, while scientific research of the performance of cutting fluids lags behind. While much has been documented about the beneficial mechanisms of tool-chip lubricity and heat transfer from varying fluid types and applications, an accurate, flexible, and expedient method for investigating cutting fluid performance lies beyond the scope of modern experimental methods. This paper proposes an experimental system and methodology that aims to simultaneously quantify the effectiveness of cutting fluid in thermal (cooling characteristics) and mechanical (frictional effects) terms. The system acquires cutting force measurements with a piezoelectric tool post dynamometer to gauge the mechanical effectiveness of the cutting fluid through the variation in friction coefficient. Thermal effectiveness is examined by comparison of thermal images of the tool flank face obtained through the use of full-field infrared imaging and a point temperature obtained from a single type-K microthermocouple embedded below the insert rake face. The system's uniqueness lies both in its ability to obtain simultaneous and real-time mechanical and thermal data, and in its application of infrared imaging technology to metal cutting in the presence of cutting fluid. Proof of concept testing was done by examining orthogonal end-turning of Al 6061-T6 with both high speed steel and carbide inserts with and without overhead application of a hybrid cutting fluid over a range of cutting conditions.