Modelling of hard part machining

The paper initially reviews the use of finite element modelling (FEM) to determine orthogonal machining performance. Over the last decade, the development and use of FEM to evaluate the effect of tool coatings, cutting environment and chip formation on cutting forces and temperatures, etc., has increased dramatically. The different chip separation criteria and FEM software used by various researchers are detailed.An FE model is presented using ABAQUS/Explicit™ to simulate continuous and segmental chip formation when machining AISI H13 tool/die steel heat treated to ∼49HRC with polycrystalline cubic boron nitride (PCBN) tools. The work utilised the shear failure criteria and element deletion/adaptive remeshing modules found in ABAQUS/Explicit. The assignment of tool/chip interface friction was dependent on the magnitude of the direct stress acting on the rake face of the tool. Experimental data involving chip morphology and cutting forces were used to validate the model. The temperature generated in the shear zone was higher with the segmented chip (up to 700°C) than with the continuous chip (up to 250°C), for the same machining parameters.