Integrity Analysis And Damage Mechanism Research Of Grinding Surface Of Diamond Devices Based On Multi-grit Simulation

Diamond material has excellent hardness,thermal conductivity,permeability and low friction coefficient,excellent optical properties.Diamond devices represented by diamond anvil,diamond cutting tool,diamond window,diamond radiator and so on have been well applied in high energy laser,large-scale integrated circuit,nuclear energy,aerospace and other cutting-edge technology fields,and gradually become the cornerstone of many advanced technology development.At present,mechanical grinding is the most simple and efficient method to process diamond material.The grinding process inevitably produces damage such as amorphous,crystal dislocation and lattice distortion,which affects the integrity of the workpiece surface and determines the application performance of diamond devices.In order to improve the grinding quality of diamond workpiece and improve the performance of diamond devices,it is very important to carry out in-depth research on the surface integrity of diamond material mechanical lapping process,analyze the mechanism of surface forming and sub-surface damage of workpiece material,and determine the influence law of different process parameters on the surface integrity of diamond material.The main contents of this paper are shown as the following parts:（1）The simulation and analysis of diamond grinding process based on molecular dynamics theory.A simulation model of diamond grinding is constructed by molecular dynamics simulation of LAMMPS.Suitable potential energy functions,solution algorithms,boundary conditions and ensembles are selected.Based on the analysis of the internal Dimensional Stress of the diamond material,the forming process of the surface of the diamond workpiece is further studied by OVITO to explore the micro-grinding effect of the chip accumulation on the unmachined area and the influence of material amorphization on the surface forming of the workpiece.（2）The simulation and analysis of surface integrity based on different grinding simulation models.Combined with different grinding models,the influence of four kinds of process parameters,such as particle size,grinding angle,grinding depth and grinding speed on the grinding force fluctuation,friction coefficient,atomic accumulation on the workpiece surface and material rebound characteristics are investigated.The grinding of diamond material is quantitatively analyzed on atomic scale.The experimental platform of diamond grinding is built,the surface topography and surface roughness of grinding workpiece under various process parameters are analyzed by AFM scanning,and the sensitivity of these grinding processes to grinding quality of workpiece surface is analyzed,so as to explore the reasonable configuration of grinding process parameters.（3）Based on the Common Neighbor Analysis method,the atomic phase transition of the grinding process of diamond is analyzed,the process and mechanism of diamond amorphous damage under mechanical grinding are explored.Combined with different grinding models,the influence of various process parameters on subsurface damage of workpieces is deeply explored by changing the four grinding parameters of grinding particle size,grinding front angle,grinding depth and grinding speed.On the basis of primary grinding,the subsurface damage of secondary grinding is analyzed,and the results of the simulation analysis are verified by the TEM electron microscopy scanning experiments.