ABSTRACT
Machining is an indispensable manufacturing process, and a flooded-type mineral oil–based coolant system still dominates the machining industry, making it unsustainable due to inefficiencies and environmental impacts (soil and water pollution on disposal). One of the plausible solutions for these shortcomings for machining could be ionic liquids (ILs). ILs are in the liquid state at room temperature and possess several desirable properties such as thermal stability, nontoxic nature, negligible vapor pressure, nonflammable, and due to ionic nature can adsorb on surfaces. ILs are also considered task-specific compounds because they can be tuned depending on the application by altering the molecular structures of cation and anion. This chapter addresses advances in the applicability of ILs as neat/lubricant additives with consideration of recent technical achievements, effect on machining parameters, environmental impacts, and prospects as an excellent potential replacement of conventional lubricants in the era of Industry 4.0. In addition, the performance of ILs as neat and lubricant additives in the minimum quantity lubrication system for various materials are also reviewed.
