表面技术2026，Vol.55Issue(1)：58-69,12.DOI:10.16490/j.cnki.issn.1001-3660.2026.01.005
多晶碳化硅纳米磨削机理的分子动力学研究
Molecular Dynamics Study on Nano-grinding Mechanism of Polycrystalline Silicon Carbide
摘要
Abstract
Silicon carbide(SiC)is widely used in high-performance fields such as aerospace,automotive,and optoelectronics due to its superior mechanical properties and optical characteristics.However,achieving high-quality surfaces through nanogrinding remains challenging due to the material's inherent hardness and the complex interactions between the grinding grit and the workpiece.To meet the high-precision machining demands of SiC in advanced manufacturing,this study investigates the effects of grain boundary characteristics and grit geometry on the material removal behavior and damage mechanisms during the nanogrinding of polycrystalline SiC. With focuses on analyzing grinding forces,grinding temperatures,stress distributions,surface topography,and subsurface damage to elucidate the mechanisms of material removal and damage during the nanogrinding of polycrystalline SiC,molecular dynamics simulations were conducted to model the nanogrinding process of SiC,revealing the material removal behavior at the atomic level under various grinding conditions.Workpiece models with different grain numbers and grain boundary densities were constructed according to the Voronoi method to examine the influence of microstructures on grinding outcomes.Simulations were conducted with different grit rake angles(-30°,-15°,0°,15°,30°)to study the material removal mechanisms and damage behaviors.The workpiece model was divided into Newtonian,thermostatic,and boundary layers,at an initial workpiece temperature of 300 K,to simulate the thermodynamic conditions of actual machining;the grit was set as a rigid body,at a grinding speed of 100 m/s and a grinding depth of 2 nm. The results showed that the average grinding force for polycrystalline SiC was lower than that for monocrystalline SiC.However,grain boundaries in polycrystalline SiC impeded dislocation motion and increased thermal resistance,leading to heat accumulation and elevated local stresses,which highlighted the significant role of grain boundaries in influencing mechanical and thermal behaviors during the grinding process.When grain size was reduced,an inverse Hall-Petch effect was triggered,softening the material and increasing the removal rate.However,anisotropic deformation of adjacent grains led to step formation at grain boundaries,degrading surface quality.Surface quality was significantly affected by grain boundary density and grain size.This suggested that while grain refinement could enhance material removal efficiency,it might also pose challenges in achieving high surface quality.Increasing the grit rake angle enhanced the material removal rate,reduced the grinding force and its fluctuation amplitude,improved surface roughness,and mitigated subsurface damage.These improvements were attributed to the reduced compressive action of the grit on the workpiece,which facilitated chip removal and heat dissipation,reducing heat accumulation in the cutting zone,thereby promoting a more efficient cutting process.These effects were critical for understanding overall grinding performance and the formation of grinding surface defects. The findings of this study reveal the significant impact of grain boundary characteristics and grit geometry on the nanogrinding process of polycrystalline SiC.Selecting appropriate grit rake angles and machining paths can help improve machining efficiency and surface quality in advanced manufacturing applications.This study provides new insights and directions for further exploring high-performance machining technologies for SiC materials,developing new grit materials,and optimizing grinding processes.关键词
分子动力学/多晶碳化硅/磨粒几何形状/亚表面损伤/晶界/表面质量Key words
molecular dynamics/polycrystalline SiC/grit geometry/subsurface damage/grain boundaries/surface quality分类
数理科学引用本文复制引用
田助新,周星辰,耿瑞文,谢启明,李立军,吴海华,章文忠,双佳俊,杨志豇..多晶碳化硅纳米磨削机理的分子动力学研究[J].表面技术,2026,55(1):58-69,12.基金项目
湖北省技术创新专项重大项目(2019AAA164) （2019AAA164）
三峡大学人才引进项目(2022Y0037) （2022Y0037）
水电机械设备设计与维护湖北省重点实验室开放基金(2023KJX04) Hubei Province's Technology Innovation Special Project(2019AAA164) （2023KJX04）
Talent Introduction Project of China Three Gorges University(2022Y0037) （2022Y0037）
Open Fund Project of Hubei Key Laboratory for Design and Maintenance of Hydropower Machinery and Equipment(2023KJX04) （2023KJX04）
