ABSTRACT
In the last few years, most countries all over the world have established strict regulations to sustain the environment. Because conventional metalworking fluids (MWFs) are classified as extremely harmful materials for the health and the environment. Thus, costly posttreatment of the MWFs is required. Many researchers have suggested some alternative solutions to overcome the MWFs ecological and hygienic risks like dry cutting. However, dry cutting showed better ecological impacts, it cannot fulfill the requirements of the machining processes. Dry cutting suffers from many shortcomings, such as thermal damages, which correspond to excessive heat generation, the high-specific energy that is a matter of concern, and conflicts with the global trend of energy saving. Nanofluids have been proposed as a promising alternative with enhanced thermal conductivity, lubrication properties, hygienic effect, and lower environmental impact. This chapter shows the different uses of nanofluids in machining processes through the fourth era of industry. Furthermore, the chapter manifests the different techniques used in preparing the nanofluids and the effect of different nano-additives in terms of machining outputs, such as surface quality, energy consumption, cutting forces, accuracy, and others. Besides, the chapter evaluates the environmental sustainability and the hygienic impact of the different types of nanofluids.
