Research on diffusion wear mechanism of WC tool cutting Al2024 based on MD

Abstract

Al2024 belongs to a typical Al-Cu-Mg series alloy. It has the advantages of high-strength, low-specific gravity, stress resistance, corrosion resistance, good heat resistance, and high fatigue resistance. It is widely used in aerospace, automobiles, ships, chemicals, and other fields. Aluminum alloys play a pivotal role in industry and manufacturing. Cemented carbide tools are often used in the processing of aluminum alloys, and diffusion wear is prone to occur during the processing. It is of great significance to study the diffusion phenomenon of WC tools in the process of cutting aluminum alloys for improving tool life and workpiece surface machining accuracy. In this paper, based on the molecular dynamics (MD) simulation method, the WC tool and the Al2024 model were established, the Morse potential parameters between the tool and the workpiece atoms were calculated, and the diffusion wear mechanism of the WC tool in the process of cutting Al2024 was studied. Through the displacement nephogram in the tool-worker X direction, it is found that the workpiece atoms have a tendency to diffuse to the tool. Using the mean square displacement (MSD) method, the diffusion velocities of Al, Cu, and Mg atoms in the workpiece were obtained. The results show that the activation energy of atomic vacancies at the grain boundary is smaller than that at the lattice, and the Al, Cu, and Mg atoms at the grain boundary of the workpiece are more likely to diffuse, and the diffusion rate of Mg atoms is the fastest. The total energy of single atoms in the cutting process was analyzed, and it was found that the energy required for Al, Cu, and Mg elements at the grain boundary of the workpiece to diffuse into the WC tool and the energy required for the Mg and Al elements at the workpiece lattice to diffuse into the WC tool were satisfied.