Analyse de l'état mécanique et microstructural des zones de frottement outil-copeau et outil-pièce en tournage

Mechanical and microstructural state analysis in tool-chip and tool-workpiece friction zones in turning

¹ LM3, URA CNRS 1219, ENSAM-Paris
² actuellement à l'ENSAM-Metz

Résumé

L'étude de la coupe présentée ici s'inscrit dans un cadre microstructural pour une meilleure compréhension des phénomènes mis en jeu dans les zones de frottement outil-copeau et outil pièce et de leurs couplages, grâce à des moyens expérimentaux (microscopie, diffraction des rayons X, analyse thermique de l'essai de coupe, mesure des efforts de coupe) et numériques (modèle micromécanique).

Abstract

The purpose of this study is the analysis of the mechanical and metallurgical phenomena occurring in the tool/workpiece and tool/chip friction zones in orthogonal cutting. The mechanical and microstructural study relies on the characterization of these surfaces, through both experimental (microscopy, X-ray diffraction) and numerical means, and on the knowledge of the temperatures and forces during cutting.

Two steels are tested : a ferrito-perlitic carbon steel (XC42. AISI 1040) and a stable austenitic steel (Z2CND17-12-02, AISI 316L). Different cutting tools are used : tungsten carbide, coated tungsten carbide and cermet. From this whole study, trends are pointed out in the characterization of the cutting products, thanks to some examples. In particular, phase transformation are studied in a thermal-mechanical-metallurgical approach, from the additional knowledge of temperatures and forces during cutting. The numerical part permits the identification of the mechanical solicitations in the second shearing zone, from the comparison of simulated and experimental textures. The identified loading is pure shear.