Wear Resistance and Friction Reducing Mechanism of Bronze-Steel Tribopair under Boundary Lubrication

The friction and wear properties of two kinds of fluorosilicone oils and PN (amine salt of alkoxyl phosphate) as lubricant additives in poly-alpha-olefin are evaluated using an Optimol SRV reciprocating friction and wear tester by bronze disc against AISI 52100 steel ball. The morphologies of worn surfaces of the bronze discs are examined using a scanning electron microscopy. In addition, the elemental compositions and chemical states of several typical elements on the worn surfaces of the bronze discs are examined by means of X-ray photoelectron spectroscopy. Results indicate that oils containing PN and fluorosilicone as additives exhibit excellent wear-resistance and low and stable friction coefficient. This is partly attributed to tribophysical and tribochemical reaction of phosphorus, nitrogen and fluorine with the sliding surfaces.