STP1501

    Study of the ZDDP Antiwear Tribofilm Formed on the DLC Coating Using AFM and XPS Techniques

    Published: Jan 2008


      Format Pages Price  
    PDF (708K) 11 $25   ADD TO CART
    Complete Source PDF (6.6M) 11 $55   ADD TO CART


    Abstract

    To meet the challenge of the increasing demand of fuel economy, in recent years low friction nonferrous coatings such as diamond-like carbon (DLC) coatings have become very popular for automotive tribo-components. The interaction of lubricant additives, which are designed for ferrous surfaces, with nonferrous coatings is an important issue for the automotive and lubricant industries. The aim of this paper is to establish a link between the evolution of antiwear zinc dialkyl dithiophosphate (ZDDP) tribofilm and the tribological performance of a DLC coating under boundary lubrication conditions. Experiments were performed in a pin-on-plate reciprocating tribotester to produce the tribofilm. Atomic force microscopy (AFM) was used to record high resolution topographical images of the ZDDP films while chemical analysis of the ZDDP tribofilms was performed using X-ray photoelectron spectroscopy (XPS). Results in this study show that the ZDDP tribofilm consists of short chain zinc pyrophosphate (Zn2P2O7) and zinc metaphosphate (ZnOP2O5), and it is formed along the raised portion of the initial marks of the DLC surface.

    Keywords:

    DLC coating, boundary lubrication, zinc dialkyl dithiophosphate, atomic force microscopy, X-ray photoelectron spectroscopy


    Author Information:

    Haque, T.
    Institute of Engineering Thermofluids, Surfaces and Interfaces (iETSI), School of Mechanical Engineering, University of Leeds, Leeds,

    Morina, A.
    Institute of Engineering Thermofluids, Surfaces and Interfaces (iETSI), School of Mechanical Engineering, University of Leeds, Leeds,

    Neville, A.
    Institute of Engineering Thermofluids, Surfaces and Interfaces (iETSI), School of Mechanical Engineering, University of Leeds, Leeds,

    Kapadia, R.
    Infineum UK Limited, Abingdon,

    Arrawsmith, S.
    Infineum UK Limited, Abingdon,


    Paper ID: STP45586S

    Committee/Subcommittee: D02.06

    DOI: 10.1520/STP45586S


    CrossRef ASTM International is a member of CrossRef.