CBN (Cubic Boron Nitride) tool is suitable for precision machining of nickel-based alloy due to its high hardness and chemical inert. Nickel-based alloys are difficult-to-cut material. When high-speed cutting nickel-based alloys with CBN tool, the temperature at tool-workpiece interface is very high. The atoms in workpiece material diffuse into the tool surface and change the performance of cutting tool, resulting in diffusion wear. Inconel 718, which is one kind of widely used nickel-based alloy, is mainly composed of nickel (Ni), iron (Fe) and chromium (Cr). In this paper, the cutting model which describes the single crystal CBN tool cutting Ni–Fe–Cr three-component alloy, and the compression and impact model of CBN tool crystal are established by using molecular dynamics (MD) method to study the diffusion of Ni, Fe and Cr atoms into CBN tool and the effects of diffusion on the properties of CBN crystal tool. The results show that the diffusion of Ni, Fe and Cr atoms into CBN tool decreases the compressive strength and impact toughness of CBN crystals and the effects degree of atom diffusion on the properties of CBN crystals are different.

CBN（立方氮化硼）刀具具有高硬度和化学惰性，因此适合于镍基合金的精密加工。镍基合金是难以切割的材料。使用CBN刀具高速切削镍基合金时，刀具-工件界面的温度很高。工件材料中的原子扩散到刀具表面并改变切削刀具的性能，从而导致扩散磨损。Inconel 718是一种广泛使用的镍基合金，主要由镍（Ni），铁（Fe）和铬（Cr）组成。本文采用分子动力学方法研究了单晶CBN刀具切削Ni-Fe-Cr三元合金的切削模型，建立了CBN刀具晶体的压缩和冲击模型。你，Fe和Cr原子进入CBN工具中以及扩散对CBN晶体工具性能的影响。结果表明，Ni，Fe和Cr原子扩散到CBN工具中会降低CBN晶体的抗压强度和冲击韧性，并且原子扩散对CBN晶体性能的影响程度也不同。