Abstract.The present study is concerned with resolving the problems pertaining to the conventional cutting fluids. Two samples of nano cutting fluids were prepared by dispersing 0.01 vol% of MWCNTs and a mixture of 0.01 vol% of MWCNTs and 0.01 vol% of nano ZnO in the soluble oil. The thermophysical properties such as the kinematic viscosity, density, flash point and the tribological properties of the prepared nano cutting fluid samples were experimentally investigated and were compared with those of plain soluble oil. In addition to this, a milling process was carried by varying the process parameters and by application of different samples of cutting fluids and an attempt was made to determine optimal cutting condition using the Taguchi optimization technique.
IntroductionMachining is often accompanied by a large amount of frictional heat at the tool, work and chip interfaces. This in turn affects the machining parameters such as the cutting force, tool wear and the surface roughness. In order to control these parameters, cutting fluids are employed in metal working processes. Effective cooling and lubrication are the most desirable properties of any cutting fluid. A study by few American institutes stated that 60% of companies spend more than 20% of their total expenses on coolants/lubricants in metal cutting operations [1]. Cutting fluids are categorized into various groups based on their derivatives, the commonly used cutting fluids being mineral oil or petroleum oil, oil-water emulsions, pastes, gels and aerosols. Straight oils are undiluted mineral or petroleum oils. They provide excellent lubrication effect between the tool and the work piece which makes them the fluid of choice for most of the honing operations and several machining processes. But the initial cost of these type of cutting fluids are high, making them unsuitable for most of the operations. Despite their high cost, the straight oil cutting fluids also possess poor heat transfer properties. Soluble oil fluids are stable emulsions of the mineral oil and water with a low oil concentration. These are least expensive and are the most commonly used because of their considerably good lubrication and heat transfer properties. However, since these types of fluids are in a highly diluted form, they tend to lose their properties with time and needs to be continuously replaced. Therefore, there exists a need to improve their properties and sustain them in order to cope up with the severity and complexity of the modern machining operations. Recently many studies have marked a massive improvement in the heat transfer and tribological properties of the base fluids on dispersion of nanoparticles. Nanofluids are stable dispersions of nanoparticles into a base fluid. The commonly used base fluids are water, oil and ethylene glycol. These nanofluids are experimentally found to possess better tribological, thermophysical, optical and electrical properties compared to their parent base fluid. Choi et al., [2] showed an enhancement of 10% in the thermal conduct...