Experimental investigation of the temperature and stress distribution in tool-chip contact zone

Abstract

The temperature at the tool-chip interface is a good estimator of the chip formation and the mechanics taking place in the cutting area. The temperature could be used as an image of the shear stress and the knowledge of the temperature can give a lot of information on cutting phenomena. Global measured value can give a clue on the local understanding of cutting but a field measurement is a way to obtain a lot more information. Conventional experimental methods as thermocouple reached their limits when trying to obtain a temperature distribution at the very contact zone. An experimental protocol has been developed using advanced infrared imaging technology in order to measure temperature distribution in both the tool and the chip during an orthogonal or oblique cutting operation. This setup also allows the estimation of several information on the chip formation so as geometrical characteristics (tool-chip contact length, chip thickness, primary shear angle) and thermo-mechanical information (heat flux dissipated in deformation zone, local interface heat balance). A study has been carried out on the effect of cutting conditions as cutting speed, feed and depth of cut on the temperature distribution along the contact zone for an elementary operation as orthogonal or oblique cutting. Once the temperature distribution is known it is possible through an analytical model to deduce other information and especially on the contact tribological conditions as local stress, or heat flux repartition. This paper presents the capability of such an experimental setup and the influence of the cutting conditions and the possible further development.