Modelling of friction phenomena in material removal processes

The understanding and modelling of friction phenomena is really important for modelling analytically and numerically the cutting operations. To perform measurement in extreme conditions such as machining conditions (high speeds, high pressures and high temperatures) a new generation of tribometer was designed. This experimental set up has been used to characterize the friction phenomena related to the machining of AISI 316L austenitic stainless steels with a TiN coated carbide insert. This paper presents a method used to obtain a new model for the friction coefficient. This process is divided into two steps. First the tribometer measures macroscopic forces induced in the pin. This is performed with various slipping speeds and forces applied on the pin to obtain a large range of macroscopic friction coefficients. These data are then used to build and load a scratching numerical model which is implemented in ABAQUS® EXPLICIT software to extract the local friction coefficient from the macroscopic scratching force ratios. In this paper, the experimental set up used to obtain the macroscopic results, the numerical model implemented in ABAQUS® EXPLICIT and the results concerning the friction between TiN coated carbide tools and AISI 316L during turning operations are described.