Tribofilm formation, friction and wear-reducing properties of some phosphorus-containing antiwear additives
File(s)
Published version
Author(s)
Luiz, Juli Felicio
Spikes, Hugh
Type
Journal Article
Abstract
The film-forming, friction and wear properties of a range of model and commercial ashless P and P/S antiwear additives have been studied. A method has been developed for removing the tribofilms formed by such additives in order to effectively quantify mild wear. In general the P/S additives studied formed thinner tribofilms but gave lower wear than the S-free P ones. In extended wear tests, three P/S additives gave wear as low, or lower, than a primary zinc dialkyldithiophosphate (ZDDP). For almost all lubricants tested the wear rate measured in short tests was considerably higher than that in long tests due to the greater contribution of running-in wear in the former. This highlights the importance of basing antiwear additive choice on reasonably long tests, where running-in becomes only a small component of the wear measured. It has been found that for both P and P/S ashless additives the addition of oil-soluble metal compounds based on Ti and Ca boosts tribofilm formation and can lead to very thick films, comparable to those formed by ZDDP. However, this thick film formation tends to be accompanied by an increase in mixed friction and also does not appear to reduce wear but may even increase it.
Date Issued
2020-09
Date Acceptance
2020-06-21
Citation
Tribology Letters, 2020, 68 (3), pp.1-24
ISSN
1023-8883
Publisher
Springer Science and Business Media LLC
Start Page
1
End Page
24
Journal / Book Title
Tribology Letters
Volume
68
Issue
3
Copyright Statement
© The Author(s) 2020. This article is licensed under a Creative Commons
Attribution 4.0 International License, which permits use, sharing,
adaptation, distribution and reproduction in any medium or format,
as long as you give appropriate credit to the original author(s) and the
source, provide a link to the Creative Commons licence, and indicate
if changes were made. The images or other third party material in this
article are included in the article’s Creative Commons licence, unless
indicated otherwise in a credit line to the material. If material is not
included in the article’s Creative Commons licence and your intended
use is not permitted by statutory regulation or exceeds the permitted
use, you will need to obtain permission directly from the copyright
holder. To view a copy of this licence, visit http://creativecommons
.org/licenses/by/4.0/.
Attribution 4.0 International License, which permits use, sharing,
adaptation, distribution and reproduction in any medium or format,
as long as you give appropriate credit to the original author(s) and the
source, provide a link to the Creative Commons licence, and indicate
if changes were made. The images or other third party material in this
article are included in the article’s Creative Commons licence, unless
indicated otherwise in a credit line to the material. If material is not
included in the article’s Creative Commons licence and your intended
use is not permitted by statutory regulation or exceeds the permitted
use, you will need to obtain permission directly from the copyright
holder. To view a copy of this licence, visit http://creativecommons
.org/licenses/by/4.0/.
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Identifier
https://link.springer.com/article/10.1007%2Fs11249-020-01315-8
Grant Number
EP/P030211/1
Subjects
Mechanical Engineering & Transports
0912 Materials Engineering
0913 Mechanical Engineering
Publication Status
Published
Article Number
75
Date Publish Online
2020-07-07