“…In general, the material, stress, velocity, temperature, and other factors affect the friction coefficient between a tool and a chip [4], but researchers in the field of tribology have been attempting to describe in detail how the friction interface process and the deformation mechanism of materials work. It is finally confirmed that in solid-solid contact, the friction interface will cause significant material changes, resulting in a third body [7,8], which is also called a friction film, a friction layer [9], a transfer layer [10], a mechanical mixing layer [11], etc. The coolant cannot successfully build a water film under centrifugal and hightemperature conditions to form a solid-solid contact for high-speed internal cooling milling [12].…”