The tribochemical mechanism of the borate modified by N-containing compound as oil additive

The tribological properties of the borate modified by N-containing compound were investigated with a four-ball tester. The boundary film on the rubbed surface were analyzed using a small area X-ray photoelectron spectrometer (XPS), the depth profiling XPS and the Auger electron spectroscopy (AES). Results of the tribological properties indicated that the borate modified by N-containing compound possesses good anti-wear and friction reduction properties, as well as high load-carrying capacity. The results of the small area XPS, the depth profiling XPS and AES analyzes illustrate that the boundary film on the wear surface is composed of C, O, B, N and Na elements, and boron element exists in four different chemical states, which is Na₃B₃O₆, BN, B-Fe-O and FeB.