Influence of hydrogen and tungsten concentration on the tribological properties of DLC/DLC contacts with ZDDP

Vengudusamy, Balasubramaniam; Green, Jonathan H.; Lamb, Gordon D.; Spikes, H. A.

doi:10.1016/j.wear.2013.01.020

Cited by 59 publications

(49 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In previous studies, contradictory findings on the tribological properties of a-C:H films lubricated with ZDDP solutions are reported [9][10][11][12][13][14][15][16][17][18][19]. Some previous works has reported that ZDDP solutions exhibited lower friction than base oil [9,10,16], whereas others has reported that ZDDP solutions exhibited higher friction than base oil [15,17,19]. From our results, we can speculate that some of these discrepancies in the frictional and wear properties may be attributed to the fact that different researchers have studied ZDDPs with differently structured alkyl chains.…”

Section: Discussionmentioning

confidence: 97%

“…ZDDPs are widely used as additives because of their excellent anti-wear and anti-seizure properties on sliding surfaces [1][2][3]. Due to their attractive properties, ZDDPs have been investigated by many research groups for the last several decades [4][5][6][7][8][9][10]. Therefore, it is well-known that ZDDP tribofilms on iron-based materials consist of gradient, patchy, and pad-like structures, which are composed of phosphate glasses, zinc phosphates, and sulfur-rich layers [1][2][3][4][5].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effects of Molecular Structure of Zinc Dialkyldithiophosphates on Tribological Properties of a Hydrogenated Amorphous Carbon Film under Boundary Lubrication

et al. 2017

View full text Add to dashboard Cite

The effects of the molecular structure of zinc dialkyldithiophosphates (ZDDPs) on the tribological properties of a hydrogenated amorphous carbon (a-C:H) film under boundary lubrication were investigated. Friction tests were performed at a-C:H/a-C:H and steel/steel contacts under lubrication with poly-alpha olefin (PAO) and PAO containing five types of ZDDPs with different alkyl groups (primary-C4 ZDDP, secondary-C4 ZDDP, primary-C6 ZDDP, primary-C8 ZDDP and primary-C12 ZDDP). All our results suggest that the structure of the alkyl chain of ZDDPs strongly influence the tribological properties of the a-C:H/a-C:H and steel/steel tribopairs lubricated with ZDDP solutions.

show abstract

Section: Discussionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Effects of Molecular Structure of Zinc Dialkyldithiophosphates on Tribological Properties of a Hydrogenated Amorphous Carbon Film under Boundary Lubrication

et al. 2017

View full text Add to dashboard Cite

show abstract

“…The WS 2 compound played the role of friction reducer due to its crystallographic structure. Formation of WS 2 -containing tribolayer was well documented for W-DLC coatings during lubricated sliding at ambient temperature [14] as well as in the temperature range of 50°C -200°C [13], [15], [16], [17], [18], [19]. For example, reactive magnetron sputtered WC-doped hydrogenated DLC coating (having multilayer structure of WC and a-C:H) showed µ~0.055 at ambient temperature due to formation of WS 2 -containing tribolayer [14].…”

Section: Introductionmentioning

confidence: 90%

“…W-doped DLC coatings are most efficient at low temperatures between ambient [14], [19] and ~100°C [15], [16], [17], [18] combined with lubricated conditions. The tribo-mechanism involves the formation of a WS 2 -containing transfer layer by reactions between the coating and the lubricant, which is highly lubricious.…”

Section: Importance Of Combined Mo and W Dopingmentioning

confidence: 99%

Friction and wear behaviour of Mo–W doped carbon-based coating during boundary lubricated sliding

Hovsepian

Mandal

Ehiasarian

et al. 2016

Applied Surface Science

View full text Add to dashboard Cite

A molybdenum and tungsten doped carbon-based coating (Mo−W−C) was developed in order to provide low friction in boundary lubricated sliding condition at ambient and at high temperature. The Mo−W−C coating showed the lowest friction coefficient among a number of commercially available state-of-the-art DLC coatings at ambient temperature. At elevated temperature (200°C), Mo−W−C coating showed a significant reduction in friction coefficient with sliding distance in contrast to DLC coatings. Raman spectroscopy revealed the importance of combined Mo and W doping for achieving low friction at both ambient and high temperature. The significant decrease in friction and wear rate was attributed to the presence of graphitic carbon debris (from coating) and 'in-situ' formed metal sulphides (WS 2 and MoS 2 , where metals were supplied from coating and sulphur from engine oil) in the transfer layer.

show abstract

“…Antiwear additives are generally known to form protective tribofilms on the surface of contacting bodies. The most common such additive is zinc dialkyl dithiophosphate (ZDDP) [16], which can form tribofilms on various materials including steel, diamond-like carbon (DLC) and Si/Al alloys [17][18][19][20][21][22][23][24][25][26][27]. Though extensively studied, the specific processes involved in formation and removal of tribofilms in these different systems are not yet fully understood.…”

Section: Introductionmentioning

confidence: 99%

A Semi-deterministic Wear Model Considering the Effect of Zinc Dialkyl Dithiophosphate Tribofilm

et al. 2015

View full text Add to dashboard Cite

Tribochemistry plays a very important role in the behaviour of systems in tribologically loaded contacts under boundary lubrication conditions. Previous works have mainly reported contact mechanics simulations for capturing the boundary lubrication regime, but the real mechanism in which tribofilms reduce wear is still unclear. In this paper, the wear prediction capabilities of a recently published mechanochemical simulation approach (Ghanbarzadeh et al. in Tribol Int, 2014) are tested. The wear model, which involves a time-and spatially dependent coefficient of wear, was tested for two additive concentrations and three temperatures at different times, and the predictions are validated against experimental results. The experiments were conducted using a mini-traction machine in a sliding/rolling condition, and the spacer layer interferometry method was used to measure the tribofilm thickness. Wear measurements have been taken using a white-light interferometry. Good agreement is seen between simulation and experiment in terms of tribofilm thickness and wear depth predictions.

show abstract

Influence of hydrogen and tungsten concentration on the tribological properties of DLC/DLC contacts with ZDDP

Cited by 59 publications

References 18 publications

Effects of Molecular Structure of Zinc Dialkyldithiophosphates on Tribological Properties of a Hydrogenated Amorphous Carbon Film under Boundary Lubrication

Effects of Molecular Structure of Zinc Dialkyldithiophosphates on Tribological Properties of a Hydrogenated Amorphous Carbon Film under Boundary Lubrication

Friction and wear behaviour of Mo–W doped carbon-based coating during boundary lubricated sliding

A Semi-deterministic Wear Model Considering the Effect of Zinc Dialkyl Dithiophosphate Tribofilm

Contact Info

Product

Resources

About