**3. The effects of parameters of nanofluids**

**Figure 22.** SEM micrographs of workpiece surface of nickel base alloy GH4169 at different lubricating conditions [18].

178 Microfluidics and Nanofluidics

Each type of nanoparticles has with different structures, shapes, and sizes, which will vary in physical and morphological features, demonstrating diverse tribological performances [35]. From **Table 1**, it can be seen that the technical properties of each type of nanoparticles are different, and so the effectiveness of various nanofluids on MQL cutting performance will be an important investigated factor.

In this section, the authors will present the effects of six different types of nanoparticles on nanofluids mainly used in MQL machining in term of MQL base fluid, types of nanoparticles, size and morphology of nanoparticles, and nanoparticle concentration.
