Experimental Analysis on Spherical Chips in High-speed Machining of Hardened AerMet100

摘要

Spherical chip appears frequently in high speed grinding of metals. It is attributed to the melt or oxidation of the small chips in grinding. Spherical chip in machining of steels is observed when the cutting speed is high enough. To clarify the formation mechanism of spherical chip in metal cutting, high speed machining of AerMet100 at cutting speeds from 40 m/min to 3000m/min was investigated. Spherical chip of AerMet100 was obtained at cutting speed range 2000-3000m/min. Optical and SEM (Scanning Electron Microscope) observations of the spherical chip was carried out. The chemical composition of the spherical ship was analyzed through X-ray energy dispersive spectroscopy (XEDS) analysis. The formation mechanism of the spherical chip was proposed. The results showed that the spherical shape of chip is due to the intense reaction between Fe of workpiece and O_2 in the air accompanying which large mount of heat is released to melt the oxide into small spheres. The formation of the spherical chip is highly influenced by cutting speed and the size of the chip (surface-volume ratio).