This paper presents a thermodynamic model for studying the energy dissipation processes such as friction, wear, and the adhesion phenomenon in order to predict the built-up layer (BUL) and built-up edge (BUE) formation conditions in dry cutting of SUS304 stainless steel. The model is composed of three parts: the extended representative contact model (RCM) at the tool and chip interface, the thermodynamic analysis within the RCM, and the growth model. At a typical region, the RCM is characterized by three material elements and two boundary elements, which support the contact conditions between two material elements. Thermodynamic analysis within the RCM reveals that apart from friction and wear, the BUL/BUE formation is also an irreversible energy dissipation process. The BUL/BUE can be called as a “dissipative structure substance,” which can reduce tool wear. Meanwhile, the RCM is an open system because it allows for the transfer of energy and matter with its surrounding. Energy exchange and mass exchange exert significant influences on the BUL/BUE growth. It is verified that the BUL/BUE growth depends significantly on four energy dissipation processes: workpiece fracture, friction, workpiece accumulation, and reduction of adhesion. In addition, the proposed model is verified by comparing simulations with the corresponding experimental results of dry cutting of SUS304 stainless steel. It is verified that the BUL/BUE develops its characteristics with cutting time and that the proposed model can accurately predict the BUL/BUE formation conditions. These results have provided a deeper understanding of the BUL/BUE formation mechanisms.
How localized are energy dissipation processes in nanoscale interactions?
