Lubricant infiltration physics and enabling technology in machining: Modeling and machinability

Lubricants are essential in machining because they significantly affect workpiece surface quality. However, owing to the diversity of lubricant types and the complexity of infiltration physics, there remains an urgent need to improve infiltration performance on the basis of the underlying physical processes. This paper systematically reviews the infiltration mechanisms of lubricants under different machining conditions. First, the influence of lubricant morphological characteristics and physicochemical properties on infiltration behavior is analyzed at the microscale, clarifying the mechanisms governing different states, including liquid, gas, and multiphase flow. Second, the interaction between the tool geometric boundary conditions and lubricant infiltration behavior is examined, providing an evaluation of infiltration performance at the workpiece surface. Finally, the microscopic mechanisms of lubricant behavior under the influence of typical energy fields are discussed, and the regulatory effect of these fields on lubricant infiltration is revealed. This review offers a theoretical reference for advancing the understanding of lubricant infiltration mechanisms and improving infiltration performance in machining.