Performance of ionic liquid as a lubricant in turning inconel 825 via minimum quantity lubrication method

Abstract

Nickel-based super alloys have low thermal conductivity, thus a large amount of heat is generated during machining, which reduces the superiority of the machined component and life of the cutting tool. Existing work is focused on the usage of ionic liquids as lubricants in turning Inconel 825. Taguchi’s L27 orthogonal array was used to detect the results of turning process factors, such as cutting speed, feed, depth of cut and environmental conditions, in three different machining environments: dry, oil under minimum quantity lubrication and ionic liquids with minimum quantity lubrication (IL). The output parameters considered were surface roughness, cutting temperature, tool wear and chip thickness. A multicriteria decision making (MCDM) method executed through the combination of an analytical hierarchy process (AHP) and technique for order preference by similarity to ideal solution (TOPSIS) was used for optimization. The results showed that ionic liquids with the minimum quantity lubrication (MQL) method minimized the surface roughness by 88 %, reduced the cutting temperature by 74 %, reduced the chip thickness by 89 % and minimized tool wear. Furthermore, the SEM study revealed the wear on a tool in turning Inconel 825 in dry, oil and ionic liquid environments. The outcomes obtained through analysis clearly prove the importance of employing ionic liquids with minimum quantity lubrication to reduce surface roughness, cutting temperature, tool wear and chip thickness.