Applying Minimum Quantity Lubrication (MQL) Method on Milling of Martensitic Stainless Steel by Using Nano Mos2 Reinforced Vegetable Cutting Fluid

Abstract

Martensitic stainless steel materials have provided some benefits for aerospace, automotive, hydroelectric engines, cutlery, defense, power hand tools, pump parts, valve seats, chisels, bushings, ball bearings, sporting equipment industry, dental and surgical instruments etc. due to their hardness, strength, and wear resistance. Machining operations such as milling, turning, drilling can be applied to give them the final form. But, these kinds of steels are specified as hard-to-machine materials owing to their high strength, low thermal conductivity and work hardening tendency during machining operations. However, martensitic stainless steels can be machined by using cutting fluids which are environmentally hazardous, unhealthy, and costly. In this study, minimum quantity lubrication (MQL) method was applied by using commercial vegetable cutting fluid and 1%wt. of nano MoS2 (Molybdenum Disulphide) particles reinforced vegetable cutting fluid during milling of AISI 420 martensitic stainless steel with uncoated Tungsten Carbide (WC) cutting tool and the sustainable milling operation was performed. The experiments were carried out at constant cutting speed, feed, and depth of cut. Two different amounts of nanofluids – pressure air mist supplied by MQL system were applied as 20ml/h and 40ml/h. In the consequence of milling operations, initial tool wear and surface roughness were investigated. According to the experimental results, the MQL method reduced the tool wear and surface roughness. In addition, minimum tool wear and surface roughness values were obtained in nano MQL milling at 40ml/h MQL flow rate.