An Experimental Investigation of the Effects MQL Using Nanofluids on Surface Roughness of Hard Milling Process

High cutting force and cutting heat are challenging problems that need to be overcome for the hard milling process. Minimum quantity lubrication (MQL) has been shown to be effective and suitable for use in hard milling due to the improving lubrication in the cutting zone. The content presented in this article is to investigate MQL using emulsion cutting oil with/without Al2O3 nanoparticles for hard milling of 60Si2Mn steel (50-52 HRC) using carbide tools. Factorial experimental design is used to evaluate the cooling condition, cutting speed and feed rate on surface roughness. Experimental results show that feed rate has the greatest influence on surface roughness among the parameters investigated, followed by cooling mode and cutting speed. MQL technique using nano cutting oil gives better machined surface quality than MQL using pure cutting oil, which has proven that the additives of Al2O3 nanoparticles to the base cutting oil has improved cooling and lubrication capability. Furthermore, the applicability of MQL method is expanded to apply for hard milling.