Performance profiling of solid lubricant for eco-friendly sustainable manufacturing

Abstract

Abstract The intense heat generation during machining is critical to the workpiece quality. Coolant and lubrication therefore play decisive roles in machining. The conventional cutting fluids employed in machining have certain limitations with regards to their use for ecological and economic reasons. However the need for sustainable manufacturing and better surface quality urged to explore the merits of the lubricants that are eco-friendly such as solid lubricants that are proved to be a feasible alternative to the conventional cutting fluids. Solid lubricants, if employed properly, could control the machining zone temperature effectively by intensive removal of heat from the machining zone. If friction at the tool and workpiece interaction can be minimized by providing the effective lubrication, the heat generated can be reduced to some extent. It will also help reduce wear, thus improving the tool life and the surface finish. These are also used to reduce the force and the energy consumption. So the performance of the solid lubricant needs to be evaluated from tribological point of view. For this, an open tribometer has been envisaged to get the friction coefficient between the coated carbide tool and the austenitic stainless steel AISI 304 workpiece at machining - type situations. Hence this study investigate the effects of the machining parameters and the different machining environments on the machinablity aspects namely surface roughness, tool wear, tool - chip contact length, net cutting specific energy, chip morphology and the chip thickness ratio while machining austenitic stainless steel AISI 304 by TiAlN coated tungsten carbide inserts of the different tool geometry. To show the effectiveness of the solid lubricant, a comparative performance analysis, under the different environments was conducted. Results indicate that there is considerable reduction in the average flank wear (35%–60%), net cutting specific energy (40%–49%); tool-chip contact length (40%–60 %), chip thickness ratio (32%–65%) and the surface roughness (10%–39%) with the solid lubricant assisted machining compared to that of wet and dry machining. This study established that the solid lubricant assisted machining is an eco-friendly sustainable manufacturing process for the industry.