The Application of Nanofluid (Nano-Graphene)/Ultrasonic Atomization Micro-Lubrication in Micro-Milling Process on SKD11 Die Steel

This study investigated the application of ultrasonic atomization lubrication system with Nanofluid additive implemented in micro-milling process on SKD11 die steel. The graphene nanoparticles are employed as the additive of Nanofluid. Ultrasonic atomization system not only can effectively improve the agglomeration phenomena of Nanoparticles in Nanofluids but also provide the benefit of particle lubrication. For this experiment, Taguchi method was adopted and L934 orthogonal array was used to explore the optimal parameters. Targeting micro-milling force evaluation as the only focus, the control parameters included the average thickness and weight percentage concentration of Nano-graphene, the amount of ultrasonic atomization, and the angle of nozzle are analyzed. Based on the analysis, the optimal combination of Nano-graphene with ultrasonic atomization micro-lubrication was found, and then compared to the case of MWCNTs with ultrasonic atomization micro-lubrication and the other case of basal liquid with ultrasonic atomization micro-lubrication. According to the experiment results, the Nanofluid with Nano-graphene added can further reduce the micro-milling force of micro-milling process that suppress the burr generated by the processing. It can achieve the goal of tool life improvement and high workpiece quality. The micro-milling force using Nano-graphene with ultrasonic atomization micro-lubrication is reduced by 7.8% and 12.9% compared to the other two lubricating fluids, respectively.