In Situ Chemical\nMapping of the Thin-Film Lubricated\nContact

In this article,\nwe propose a direct measurement of the distribution\nof two different chemical species in a thin-film lubricated contact\nunder pure rolling conditions. The two chemical species were a carbonyl\nfrom an ester bond of a polyalphametacrylate (PAMA) polymer and an\nether bond of a polyalphalycol (PAG) molecule, formulated in low-viscosity\nfluids using a mineral polyalphaolefin (PAO). A full chemical mapping\nof the lubricated contact region was provided thanks to the Bastet\ntribometer consisting of a ball-on-disk tribometer placed under a\nmicroscope coupled with an infrared spectrometer. By following the\nspecific infrared stretching band of these two species in the inlet,\ncontact, and cavitation areas, we showed how these molecules penetrate\nthe high-pressure contact zone and participate in the film-formation.