Abstract: Micromilling has obvious advantages in manufacturing intricate 3D microstructure parts that needed for a wide range of applications in the sector of aerospace etc. There are big difference between micromilling and macromilling in machining mechanism, surface quality requirement and so on, so it is necessary to study the machining mechanism of micromilling. The research progress of the size effect mechanism of cutting edge radius, the influence mechanism of tool runout to machining process, burr formation mechanism and surface formation mechanism at home and abroad are reviewed, and introduce the difference between micromilling and macromilling in this four parts, what’s more, the reason, damage and research progress of size effect mechanism of cutting edge radius and tool runout are analyzed, the burr formation mechanism and surface formation mechanism are summarized from simulation and experiment, and the influence factors are also studied, some methods to suppress the burr are proposed. Finally, explore the problems in machining mechanism that still need to pay attention to, and put forward some suggestions for its development direction.

Key words: micromilling;machining mechanism;cutting edge radius;tool runout;burr formation;surface roughness