Experimental study on cutting force and surface quality of Aramid fiber reinforced polymer based on minimum quantity lubrication

In order to explore the milling mechanism of aramid fiber reinforced polymer under minimal quantity lubrication and improve the milling quality of aramid fiber reinforced polymer, the milling experiments of aramid fiber reinforced polymer were carried out under dry cutting and minimal quantity lubrication, and the cutting force, fiber section, and surface quality were compared and analyzed. The experiment results show that in the dry cutting state, the surface burr is more, the surface quality is poor, the fiber section is rough, and the resin matrix has a melting trend, accompanied by the phenomenon of chip wrapping around the tool, tooltip collapse, and coating peeling. In minimal quantity lubrication, the surface burr is reduced, the surface quality is good, the fiber section is neat, and the resin interface is clean and tidy. The resin matrix has no melting trend, the tooltip is only slightly worn, and the phenomenon of chip entanglement is effectively avoided. Further research shows that the minimal quantity lubrication can reduce the temperature and friction, enhance the stiffness of the fiber, and change the fracture model of the fiber to a certain extent, that is, from bending to tensile fracture (or accompanied by tensile phenomenon) to shear fracture, which also leads to the overall high cutting force. The total milling force synthesized by the average value increases from 2.45 N to 20.93 N, with a maximum increase of 88.29%. However, due to the cooling and friction reduction of the lubricating fluid and the chip removal and diversion, the overall fluctuation of the cutting force under the minimal quantity lubrication condition is reduced. The overall cutting force is more stable than that under dry cutting conditions. The results show that the milling quality is improved under minimal quantity lubrication, the cutting force is more significant but more stable, and the milling process is more stable. This study has important reference significance for milling composites (especially resin matrix composites) under the condition of minimal quantity lubrication.