Abstract
Abstract
In this paper, existing models for the tool-chip contact length are reviewed with regards to high-speed machining theory. Results of an investigation into the tool-chip contact length and tool wear of uncoated tungsten-based cemented carbide tools for dry high-speed turning of EN19 alloy steel are presented. The tests were conducted at cutting speeds ranging between 200 and 1200m/min with feed rates of 0.14 and 0.2 mm/rev and a constant depth of cut of 0.1 mm. From measurements, the effect of cutting speed on contact length and tool life has been determined and several important relationships established. It was found that the contact length changes according to the contact phenomena in the tool-chip interface zone, which is predominantly affected by the cutting speed. Moreover, the influence of the cutting speed on the contact length changes significantly from conventional to high-speed cutting environments. The study concludes that existing models are quantitatively inadequate for predicting tool-chip contact lengths in high speed turning.