Effects of Machining Parameters on Total Cutting Force in Hard Turning Process of Hardened 90CrSi Steel Using Carbide Insert with MoS2 Nanofluid MQL

Abstract

Minimum Quantity Lubrication (MQL) is widely used in machining, especially hard machining. However, this method has many limitations regarding cooling and lubrication capabilities. In recent years, nano-cutting oils have been researched and applied in machining to improve the lubrication and cooling efficiency of the MQL method. In this research, the machinability of 90CrSi steel with carbide inserts using nanofluid with different concentrations (1%, 1.5%, and 3%) of molybdenum disulfide (MoS2) nanoparticles in emulsion oil was evaluated by applying Box-Behnken optimization model. Carbide inserts commonly used to machine the low hardness steel (below 35HRC) have been used to cut hardened steel with high hardness (59-62HRC) by applying the MQL technology with MoS2 nanofluid. A mathematical model was also used to predict the cutting resultant force value in the hard turning process under MQL conditions using MoS2 nanofluid. The obtained results indicate that the total cutting force reached the minimum value (328 N) with the MoS2 nanoparticle concentration of 1.985%, a cutting speed of 80 m/min, and a feed rate of 0.138 mm/rev. In particular, the work has also provided technical guides for different machining conditions.