Contribution à la détermination de critères de dégradation d’un outil de coupe lors des opérations d'usinage.

Abstract

In the field of machining, the cutting tools wear leads to a quality gradation of the machined workpiece, particularly in terms of surface state and geometric precision. So, it is important of disposing a criterion enabling of follow the degradation of a tool during a machining operation and therefore of decide on a possible change of tool. The cutting pad damage allows of followed of the developments of wear during a machining operation. The work presented in this memory aims to follow the evolution of tool wear as a function of machining time. During machining, some degradation criteria of the cutting tool were determined. The influence of the cut parameters (Vc, f and ap) on wear and roughness of the machined workpiece had been defined as well as the evolution of wear on the surface quality. The main objective is to improve productivity. The experimental study obtained results which through them the wear ""Vb"" was identified as a direct criterion, and as the main indirect criterion: the temperature on the cutting face. Both criteria influenced the cutting tool wear by abrasion, adhesion and diffusion phenomena. In another part, a simulation study of the cut temperature profile using the Finite Element Method (MEF) was conducted to obtain a numerical model very close to the experimental practical approach. The study confirms the cutting moment at the tool tip and shows the necessity to take into account moments in the energy balance.