Development of a Carbon Nano Tube (CNT) Base Lubrication System for Higher Quality and Productivity in CNC Heavy Duty Machining

In this research work, a novel Carbon Nano Tube (CNT) nano-lubrication system will be developed for heavy duty machining process (CNC milling) for high production rate and product quality. The ECOCUT SSN 322 neat lubricant oil type with 40.2 cSt at 40 C from FUCHS, which is commonly used as a cutting fluid in Saudi metal machining companies, will be used as a base oil. This oil is free from phenol, chlorine and other additive. The CNT nano-lubricant will be prepared by adding functionalized CNT nanoparticles with an average size of 515 nm to the mineral oil followed by sonification (240 W, 40 kHz, 500 W) for 48 h in order to suspend the particle homogeneously in the mixture. To deliver the oil to the toolchip interface area, the MQL system will be used. The experimentation will be carried out using a thin-pulsed jet nozzle and controlled by a variable speed control drive. In case of using nanoparticle suspended lubrication system, the nozzle has to be equipped with additional air nozzle to accelerate the lubricant into the cutting zone and to reduce the oil consumption. The effects of using CNT nano-lubricant on machining performance (cutting temperature, surface roughness, cutting force and chip thickness ratio) will be investigated and the optimum CNT nano-lubricant parameters under different concentrations of nanoparticles, nozzle orientation and air pressure will be introduced to achieve correct lubrication conditions for the lowest cutting force, cutting temperature and surface roughness. Taguchi optimization method will be used. Furthermore, analyses on surface roughness and cutting force have to be conducted using signal-to-noise (S/N) response analysis and the analysis of variance (Pareto ANOVA) to determine which process parameters are significant. Finally, the quality of CNT nano-lubricant in term of kinematic viscosity and colloidal stability will be investigated.