Grinding performance and self-lubrication mechanism of phenolic resin-bonded grinding wheel filled with inclusion complex of β-cyclodextrin and dialkyl pentasulfide

To minimize friction at the grinding wheel-workpiece interface, a nanosized lubricant complex of β-cyclodextrin (β-CD) and dialkyl pentasulfide (RC2540) was proposed as filler to phenolic resin-bonded grinding wheels. Complex-filled grinding wheels with different filling content (5, 10, 15, and 20 wt%) were prepared by the cold compression method and the tribological properties of the wheel specimens were investigated under different speed and load conditions. The grinding performance of the complex-filled grinding wheels was compared with that of an ordinary grinding wheel under different liquid coolant conditions (water and emulsified liquid). The experimental results suggest that the complex-filled grinding wheel considerably improves the tribological and grinding performance compared with those of the ordinary grinding wheel. A complex-filled wheel with 10 wt% complex is recommended because it provides not only higher grinding ratio and lower grinding force but also better surface finish. In addition, XPS analysis was used to investigate the workpiece surface. RC2540 is found to be released as the complex decomposes. The enhanced tribological and grinding performances of the wheel are attributed to the formation of an anti-friction and anti-wear self-lubricating layer comprising sulfide and carbon-deposited films, which improve the surface quality

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

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