The effects of cutting tool thermal conductivity on tool-chip contact length and cyclic chip formation in machining with grooved tools

This paper presents an experimental analysis of the effects of cutting tool thermal conductivity on machining performance of grooved tools. A new methodology for defining the tool-chip contact length in grooved tools is proposed. Performance of uncoated carbide grooved tools tested under a range of thermal conductivities (32-92 W/m deg.K) are correlated with the variations of cyclic cutting forces, developed chip length, chip thickness and chip breaking patterns. The thickness of the retarded zone and the grain elongation orientation in the chip are measured along the curled chip and their strong influence on the chip formation process is shown.