关键词: CF/PEEK复合材料, 螺旋铣孔, 力-热耦合, 表面及亚表面质量

Abstract: In order to deeply investigate the influencing mechanism of thermo-mechanical coupling effects on the surface and subsurface morphology of machined hole walls during the helical milling of CF/PEEK composites. A microscopic simulation analysis was conducted to elucidate the failure mechanisms encompassing fiber fracture,matrix fragmentation,and interfacial debonding during the cutting process. An experimental study was also conducted on spiral milling to investigate the effects of process parameters,cutting forces and cutting heat on the surface quality which includes the roughness at the entrance and exit holes,the overall hole wall roughness,and the subsurface damage. Research results indicate that the phenomenon of matrix smearing,induced by heat accumulation,results in a significantly lower surface roughness at the exit orifice wall compared to that at the entrance. The overall roughness of the hole wall decreases with the increase in rotational speed and increases with the increase in revolution speed. When the pitch is less than 0.5 mm,the roughness increases with the increase of pitch;when the pitch exceeds 0.5 mm,the roughness decreases with further increase in pitch. This phenomenon occurs because as the pitch increases,the cutting force rises accordingly,leading to an elevation of temperature. Excessive temperatures induce material smearing on the substrate,consequently reducing surface roughness. The fiber orientation angle and thermo-mechanical coupling exert a significant influence on both surface and subsurface damage zones of hole walls.

Key words: CF/PEEK composite material, helical milling, thermo-mechanical coupling, surface and subsurface quality