Synergistic Lubrication Mechanism of Nano-Fluid and Grinding Wheel Prepared by CNTs@T304 Nano-Capsules

Abstract

Grinding fluid often struggles to enter the grinding area and overcoming this challenge has been a major focus of research in recent years. Therefore, CNTs@T304 nano-capsules are prepared by filling the cavities of CNTs with a lubricant of T304. CNTs@T304 nano-capsules were used as an additive in this paper to prepare resin grinding wheels and nanofluids, respectively. The resin wheels filled with nano-capsules were used for grinding under the lubrication of nanofluids, and T304 could then be released to the grinding area to play a self-lubricating role during grinding. First, CNTs@T304 nano-capsules were characterized, and the properties of the prepared grinding wheels and nanofluids were tested. Second, the effects of the filling of nano-capsules and grinding speed on the grinding force, grinding temperature, surface roughness, and grinding ratio were studied. Finally, the lubrication mechanism of the nano-capsules was revealed through surface analysis of the workpiece. The results suggested that nano-capsules had good thermal stability and the nanofluid prepared from them exhibited good dispersion stability and thermal conductivity. The grinding wheel was found to satisfy the service conditions when the filling content was less than 15%. Compared with a common wheel, the grinding force and grinding temperature were reduced by 24% and 28%, respectively, and the surface roughness of the workpiece and the grinding ratio were increased by 18% and by 21%, respectively, when grinding GCr15 steel with the nano-capsule wheel. Lubrication with nanofluids could further reduce the grinding force, grinding temperature, and surface roughness values. During grinding, the self-lubrication film formed by the T304 released from the nano-capsules in the wheel served first and foremost as a lubricant. The intervention of the nanofluid enhanced the heat-exchange effect and lubrication efficiency in the grinding zone.