关键词: 镍基合金, 陶瓷刀具, 纳观切削, 分子动力学, 单一界面

Abstract: Through macro experiments, it was found that during the cutting processes, the Al2O3/SiC interface of the tool breaks, and the macro mechanical properties of the material depended on the microstructure. Therefore, the molecular dynamics model for the cutting of Inconel718 nickel-based alloy with ceramic tool toughened alumina based on silicon carbide and the three-dimensional interface model of Al2O3/SiC were established to analyze the interface behaviors of the cutting processes of toughened alumina based on silicon carbide from the atomic scale. Based on the original potential function, the Morse potential function between the tool and the workpiece atoms, as well as between the matrix and toughening inside the tool was calculated, and the interface binding energy of single-phase Al2O3, single-phase SiC and complex phase Al2O3/SiC single interface was calculated respectively. Results show that compared with single phase interface, the complex phase Al2O3/SiC interface bonding strength is higher, SiC toughening can enhance the toughness and strength of the tools. However, during the cutting processes, the workpiece atom diffuses into the tool, and the interface bonding energy between the tool matrix and the toughened interface is calculated. It is found that the diffusion reduces the interface bonding strength of the tools and makes the tool fracture at the interfaces of Al2O3/SiC.

Key words: nickel base alloy, ceramic tool, nano cutting, molecular dynamics, single interface