USE OF NANO HEXAGONAL BOR NITRIDE (HBN) ADDED CUTTING FLUID IN MILLING OF HARD TO CUT MATERIALS

Abstract

In machining processes, MQL method is substantially preferred in terms ofsustainable production because of lower usage of cutting fluid and better cuttingperformance in comparison with traditional techniques. On the other hand, it isalso critical that the cutting fluid used is not hazardous to human andenvironmental health. In the present study, we aimed to investigate the cuttingperformance of AISI O2 steel in the presence of the cutting fluid containingvarious amounts of environmentally friendly Nano hexagonal boron nitride(Nano h-BN) based ethylene glycol (EG) by minimum quantity lubrication (MQL)method. Nano h-BN at 1% and 2% percentage by volume was added to theethylene glycol and sonication was carried out for one hour for both preparedcutting fluids. Based on the experimental results using prepared cutting fluids,the highest cutting tool life was obtained in tests using 2% h-BN containingcutting fluid with 2.4 m cutting length. The improvement in tool life wasapproximately 46% using 2% h-BN containing cutting fluid compared to using1% h-BN containing cutting fluid in milling tests. 2% h-BN containing cuttingfluid compared to dry conditions in terms of tool life, the increase wasapproximately 78%. The improvement in surface roughness value measured onmilled surface of workpiece material was approximately 60% using 2% h-BNcontaining cutting fluid compared to dry conditions. Compared to using 1% h-BN containing cutting fluid the improvement in surface roughness values wasapproximately 46%. A reduction in the cutting forces measured by the increasedh-BN ratio in the prepared ethylene glycol based cutting fluid has occurred. As aresult of SEM images and EDS analysis of worn tools, it was observed that thedominant wear mechanism was abrasion in all applied tests.