Study and Comparison of Lubricity of Green and Commercial Cutting Fluid Using Tool-Chip Tribometer

Abstract

A lubricant is a substance introduced between surfaces in mutual contact to reduce friction, which ultimately reduces the heat generated when the surfaces move. Liquid lubricant, designed specifically for metalworking processes, such as turning, drilling, milling etc. is known as cutting fluids (CF). Cutting fluid is a blend or combination of oil, emulsifier and additives, mostly derived from chemicals or petroleum products. However, it has got many side effects as it is toxic and harmful to environment during its disposal. Hence, vegetable based cutting fluid or green cutting fluid (GCF) is being developed and gaining importance with time. Properties of these cutting fluids are dependent on the nature of the base-oil, nature of surfactants and the properties of water used to make the CF. These fluids act on the nascent surfaces generated during cutting to form a low friction boundary layer as they slide past the cutting tool. We propose a unique tool-chip tribometer (TCT) in which these boundary layers, formed by the action of lubricants on freshly cut surfaces, can be generated and their tribological properties alone studied in isolation. This equipment can be used to study the fundamental mechanisms of the lubrication using emulsions on nascent surfaces and can be used in optimizing the composition of such fluids. The scope of this work is to assess different cutting fluids in this tool-chip tribometer. The tribological performances of metal cutting on nascent surfaces are compared. Unlike in the conventional methods of assessing the lubricity of cutting fluids using cutting tests, here the friction has been evaluated separately from cutting forces.

Keywords

• tribology
• cutting fluids
• coefficient of friction
• tribometer
• surface roughness