Study on Phase Transformation in Cutting Nickel-Based Superalloy GH4169 Based on Molecular Dynamics

Abstract

GH4169 alloy is a representative nickel-based superalloy, which is widely used in the aerospace field. However, GH4169 is prone to phase change during cutting. At the nanoscale, few studies have revealed the formation of phase transition and the relationship between cutting parameters and phase transition formation. Therefore, the phase transformation mechanism of the CBN (cubic boron nitride) cutting tool in nano-cutting nickel-based superalloy GH4169 was studied by the molecular dynamics (MD) method. Dislocation nucleation and dislocation motion in the cutting process were studied. The variation of dislocation density and cutting force and the internal stress distribution of the workpiece are analyzed. The influence of cutting depth on phase change evolution during the cutting process was studied by radial distribution function, coordination number analysis, and common neighbor analysis. The results show that the increase of cutting depth makes the dislocation density increase obviously, the required cutting force is larger, and the stress concentration is more significant. At the same time, the cutting depth will also affect the transformation of the crystal structure. The greater the cutting depth, the more intense the phase change inside the workpiece.