Tribological Characteristics of Lubricating Oils with Ammonium Thiophosphate Under Electromagnetic Field

Abstract

Tribological properties of lubricating oil containing T307 with and without electromagnetic field affection were evaluated on a modified four-ball tribo-tester. The morphologies and chemical states of several typical elements on the worn surfaces were examined by scanning electron microscope(SEM) and X-ray photoelectron spectroscopy(XPS). Then the mechanisms were discussed. The results indicate that the wear scar diameters of worn surfaces lubricated with the T307-doped oils and coefficients of friction obtained from electromagnetic field were bigger than those obtained from non-electromagnetic field. It can be attributed to the negative effect of the electromagnetic field on the combination of elemental phosphorus, sulfur, oxygen and nitrogen in T307 with metal surface, which has an undesirable effect on the formation of the tribo-chemical reaction films, and resulted by the tribo-diffussion of functional elements in T307 to the subsurface induced by electromagnetism. Moreover, the influencing mechanism of electromagnetic field was analyzed considering the molecular structure and active elements.

Keywords

• ammonium thiophosphate
• electromagnetic field
• friction and wear property
• diffusion