Evolution of contact lengths during the turning of treated Ti64 β

Abstract

Abstract. One of the main ways to increase productivity during the machining of titanium alloy parts is to control the wear mechanisms and consequently the life of the cutting tools. The state-of-the-art shows wear phenomena generated mainly by diffusion. The latter is due to the intrinsic physical properties of titanium generating high temperatures on the cutting and relief faces. Concerning the secondary cutting zone, the wear phenomena result from thermomechanical actions induced by the contact between the secondary zone of the chip and the cutting face of the tool. The analysis of the contact lengths, divided into two parts (sliding contact and sticking contact), is then a strong indicator to be privileged in order to allow the understanding of the present mechanisms. This analysis is even more important when machining processed Ti64  in which chip formation is no longer periodic but a function of the angle between the primary shear band and the orientation of the individual colonies comprising the titanium. The purpose of this article is the analysis of the contact lengths during the machining of Ti64 treated  . After having presented the experimental device allowing visualising the evolution of the contact length between the chip and the cutting face, a statistical analysis based on the collected images makes it possible to put forward the differences of sliding behaviour on the cutting face. It appears that the distribution of the collected values allows explaining and extrapolating the wear appearing on the cutting face.