Study on tool wear mechanism under cryogenic CO2-assisted minimum quantity lubrication technology

Abstract

Cryogenic CO 2 -assisted minimum quantity lubrication milling technology is a green processing technology with broad application prospects. Aiming at the problem of tool wear in the application of cryogenic CO 2 cooling assisted minimum quantity lubrication in di cult-to-machine materials and the in uence of relevant parameters on tool wear, this study used coated cemented carbide tools to perform milling experiments under cryogenic CO 2 -assisted minimum quantity lubrication technology conditions. The micromorphology of the tool rake face and chip was observed, and the energy spectrum of the tool chip contact area was analyzed. The results showed that reducing CO 2 temperature and increasing the oil ow of minimum quantity lubrication can improve the tool wear. The tool wear mechanisms under cryogenic CO 2 -assisted minimum quantity lubrication were mainly abrasive wear, diffusion wear, and oxidation wear. The chip sawtooth degree of the optimal parameter group was more conducive to chip breaking than that of dry cutting and wet cutting groups. The temperature of the tool-chip contact area is an important factor affecting tool wear, the higher the temperature, the faster the tool wear. At the same time, it is veri ed that cryogenic CO 2 -assisted minimum quantity lubrication technology can replace cutting uid in hard-to-machine materials under certain conditions.

Parameter optimization of the MQL nozzle by the computational fluid dynamics

“…On the one hand, the purpose of lubrication, cooling, and chip removal is achieved, which can prolong the tool life and improve the machining quality; on the other hand, it causes great damage to the natural environment, poses a threat to the health of machine tool operators [1][2][3] and results in high cost and consumption [4][5][6]. In recent years, minimum quantity lubrication (MQL) cutting technology has achieved good machining results [7,8]. Çamlı, et al [9] focused on the influence of MQL in the machining of steel parts for rail wheels, results showed that the MQL can reduce the surface roughness and tool wear.…”