An approach to improve the load-carrying capacity of zinc dithiophosphate

By mixing 0.5wt.% silver complex with 2-ethylhexyl phosphonic acid mono 2-ethylhexylester (AgL·HL) into a conventional zinc dithiophosphate (ZDTP), a new compounded extreme-pressure and antiwear as well as antiseizure additive was obtained. The antiseizure and load-carrying performance of the mixture (Zn-AgDTP) was significantly improved in comparison with ZDTP and AgL·HL. The synergistic action and tribochemical mechanism is proposed on the basis of the worn surface analysis by scanning Auger microprobe (SAM), X-ray photoelectron spectroscopy (XPS) and X-ray micro-diffraction (XRD).