Enhancing tool life, and reducing power consumption and surface roughness in milling processes by nanolubricants and laser surface texturing

Abstract

In this study, the effect of applying two different laser surface texturing (LST) patterns to cutting tools, as well as adding nanoparticles (NPs) to a lubricating cutting fluid in a machining process carried out in a Computer Numerical Control (CNC) machine were analyzed. Commonly, machining operations involve high wear of cutting inserts that limit their useful life, provide a poor surface finish of the workpiece and high energy consumption of the process, all of which increase production costs. The texturing patterns proposed were micro-circles and micro-channels and were applied on the rake face of the cutting tools. The NP selected for this study was a montmorillonite nanoclay (MMT) due to its ability to be produced naturally, and for being inexpensive and environmentally friendly. A concentration of 0.13 wt% was used for preparing the nanolubricant cutting fluids. An AISI 1018 steel was selected for the milling experiments at fixed machining parameters. The response variables investigated were: spindle load (related to power and energy consumption of the milling process), radius of the cutting insert (related to wear of the tool), and surface roughness of the steel plates (related to surface quality). The statistical and graphical analyses showed that for spindle load an improvement of up to 11% was found when LST of micro-channels and NPs where combined, whereas no effect was found when they were applied separately. For surface roughness, using tools with textured micro-channels or adding NPs to the cutting fluid were both beneficial individually. In the case of cutting insert radius both micro-circles and micro-channels reduced wear by 64% and 55%, respectively, compared to no LST. The results obtained in this study demonstrate that there is a synergistic effect found when combining LST patterns on cutting tools and adding NPs to the lubricant that increases the efficiency of the milling processes by reducing wear of the cutting tool, improving surface finish, and lowering spindle load.