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The role of sulphur in ZDDP‐induced reaction films formed in the presence of ZDDP: Contribution of electron spectroscopic imaging technique
Author(s) -
Hallouis M.,
Belin M.,
Martin J. M.
Publication year - 1990
Publication title -
lubrication science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.632
H-Index - 36
eISSN - 1557-6833
pISSN - 0954-0075
DOI - 10.1002/ls.3010020405
Subject(s) - sulfur , crystallite , ferrous , zinc , amorphous solid , transmission electron microscopy , materials science , degradation (telecommunications) , chemistry , chemical engineering , metallurgy , crystallography , nanotechnology , telecommunications , computer science , engineering
The anti‐wear action of zinc dithiophosphate (ZDDP), extensively used in engine oils, is here studied by analysis of wear particles generated during a friction test between two ferrous substrates. It is known in this case that the interfacial film is complex, and contains elements from surfaces, environment and degradation products of the additive. This paper deals with the presence and the form of sulphur species in the constitution of this film. Analytical Transmission Electron Microscopy (TEM, STEM, EDS and EELS filtered images) of particles shows that sulphur is in the form of small crystallites of iron sulphide Fe 7 S 8 , embedded in an amorphous phosphate matrix. Wear tests performed at different normal loads show the variation of the P/S ratio in the particles. The results are discussed.