Friction and wear performance evaluation of bio-lubricants and DLC coatings on cam/tappet interface of internal combustion engines

Journal article


Rehan Zahid, Muhammad Usman Bhutta, Riaz Ahmad Mufti, Muhammad Usman Abdullah, Haji Hassan Masjuki, Mahendra Varman, Muhammad Abul Kalam, Mian Ashfaq Ali, Jawad Aslam and Khalid Akhtar 2021. Friction and wear performance evaluation of bio-lubricants and DLC coatings on cam/tappet interface of internal combustion engines. Materials. 14 (23), p. 7206. https://doi.org/10.3390/ma14237206
AuthorsRehan Zahid, Muhammad Usman Bhutta, Riaz Ahmad Mufti, Muhammad Usman Abdullah, Haji Hassan Masjuki, Mahendra Varman, Muhammad Abul Kalam, Mian Ashfaq Ali, Jawad Aslam and Khalid Akhtar
Abstract

The environmental concerns associated with artificially formulated engine oils have forced a shift towards bio-based lubricants. The deposition of hard coatings on engine components and migrating to environmentally friendly green lubricants can help in this regard. Chemically modified forms of vegetable oils, with better low-temperature characteristics and enhanced thermo-oxidative stability, are suitable substitutes to conventional lubricant base oils. The research presented in this manuscript was undertaken to experimentally investigate the wear and friction performance of a possible future generation of an environmentally friendly bio-based lubricant as a potential replacement for conventional engine lubricants. In order to quantify the tribological benefits which can be gained by the deposition of DLC coatings, (an (a-C:H) hydrogenated DLC coating and an (a-C:H:W) tungsten-doped DLC coating) were applied on the cam/tappet interface of a direct acting valve train assembly of an internal combustion engine. The tribological correlation between DLC-coated engine components, lubricant base oils and lubricant additives have been thoroughly investigated in this study using actual engine operating conditions. Two additive-free base oils (polyalphaolefines (PAO) and chemically-modified palm oil (TMP)) and two multi-additive-containing lubricants were used in this investigation. Real-time drive torque was measured to determine the friction force, detailed post-test analysis was performed, which involved the use of a specialized jig to measure camlobe wear. An optical profilometer was used to measure the wear on the tappet, high-resolution scanning electron microscopy was employed to study the wear mechanism and energy-dispersive X-ray spectroscopy was performed on the tested samples to qualitatively access the degradation of the coating. When using additive-free TMP, a low friction coefficient was observed for the cam/tappet interface. The presence of additives further improved the friction characteristics of TMP, resulting in reduced average friction torque values. A tremendous enhancement in wear performance was recorded with a-C:H-coated parts and the coating was able to withstand the test conditions with little or no delamination.

KeywordsDiamond-like carbon (DLC) coatings; Bio-lubricants; Lubricant additives; Cam/tappet interface; Scanning electron microscopy (SEM); Energy dispersive X-ray spectroscopy (EDS)
Year2021
JournalMaterials
Journal citation14 (23), p. 7206
PublisherMDPI
ISSN1996 1944
Digital Object Identifier (DOI)https://doi.org/10.3390/ma14237206
Official URLhttps://www.mdpi.com/1996-1944/14/23/7206
Publication dates
Online26 Nov 2021
Publication process dates
Accepted18 Oct 2021
Deposited26 Jul 2023
Publisher's version
License
Output statusPublished
Permalink -

https://repository.canterbury.ac.uk/item/951v5/friction-and-wear-performance-evaluation-of-bio-lubricants-and-dlc-coatings-on-cam-tappet-interface-of-internal-combustion-engines

Download files


Publisher's version
materials-14-07206.pdf
License: CC BY 4.0

  • 60
    total views
  • 7
    total downloads
  • 7
    views this month
  • 0
    downloads this month

Export as

Related outputs

Experimental investigation of engine valve train friction considering effects of operating conditions and WPC surface treatment
Muhammad Usman Bhutta, Muhammad Huzaifa Najeeb, Muhammad Usman Abdullah, Samiur Rahman Shah, Muhammad Khurram, Riaz Ahmad Mufti, Kiyotaka Ogawa, Jawad Aslam, Rehan Zahid, Mian Ashfaq Ali and Muazzam Arshad 2023. Experimental investigation of engine valve train friction considering effects of operating conditions and WPC surface treatment. Materials. https://doi.org/10.3390/ma16093431
Corrosion mechanisms of 304L NAG in boiling 9M HNO3 containing Cr (VI) ions
Shagufta Khan, Adil Saeed, Mian Hammad Nazir, Muhammad Usman Abdullah and Zulfiqar Ahmad Khan 2023. Corrosion mechanisms of 304L NAG in boiling 9M HNO3 containing Cr (VI) ions. Sustainability. 15 (2), p. 916. https://doi.org/10.3390/su15020916
A multiscale overview of modelling rolling cyclic fatigue in bearing elements
Abdullah, U. and Khan, Z.A. 2022. A multiscale overview of modelling rolling cyclic fatigue in bearing elements. Materials. 15 (17), p. 5885. https://doi.org/10.3390/ma15175885
Further investigations and parametric analysis of microstructural alterations under rolling contact fatigue
Abdullah, U. and Khan, Z.A. 2022. Further investigations and parametric analysis of microstructural alterations under rolling contact fatigue. Materials. 15 (22), p. 8072. https://doi.org/10.3390/ma15228072
Development of white etching bands under accelerated rolling contact fatigue
Muhammad U. Abdullah, Zulfiqar A. Khan, Wolfram Kruhoeffer, Toni Blass and Bernd Vierneusel 2021. Development of white etching bands under accelerated rolling contact fatigue. Tribology International. 164, p. 107240. https://doi.org/10.1016/j.triboint.2021.107240
Roller sliding in engine valve train: Effect of oil film thickness considering lubricant composition
Muhammad Khurram, Riaz Ahmad Mufti, Muhammad Usman Bhutta, Naqash Afzal, Muhammad Usman Abdullah, Sami ur Rahman, Saif ur Rehman, Rehan Zahid, Khalid Mahmood, Mian Ashfaq and Muhammad Umar 2020. Roller sliding in engine valve train: Effect of oil film thickness considering lubricant composition. Tribology International. https://doi.org/https://doi.org/10.1016/j.triboint.2019.06.022
Evaluation of dark etching regions for standard bearing steel under accelerated rolling contact fatigue
Muhammad U. Abdullah, Zulfiqar A. Khan and Wolfram Kruhoeffer 2020. Evaluation of dark etching regions for standard bearing steel under accelerated rolling contact fatigue. Tribology International. 152, p. 106579. https://doi.org/10.1016/j.triboint.2020.106579
A 3D finite element model of rolling contact fatigue for evolved material response and residual stress estimation
Muhammad U Abdullah, Zulfiqar A Khan, Wolfram Kruhoeffer and Toni Blass 2020. A 3D finite element model of rolling contact fatigue for evolved material response and residual stress estimation. Tribology Letters. 66 (122). https://doi.org/10.1007/s11249-020-01359-w
Tribological characteristics comparison of formulated palm trimethylolpropane ester and polyalphaolefin for cam/tappet interface of direct acting valve train system
Rehan Zahid, Masjuki Hj. Hassan, Abdullah Alabdulkarem, Mahendra Varman, Md Abul Kalam, Riaz Ahmad Mufti, Nurin Wahidah Mohd Zulkifli, Mubashir Gulzar, Muhammad Usman Bhutta, Mian Ashfaq Ali, Usman Abdullah and Robiah H Yunus 2018. Tribological characteristics comparison of formulated palm trimethylolpropane ester and polyalphaolefin for cam/tappet interface of direct acting valve train system. Industrial Lubrication and Tribology. https://doi.org/10.1108/ILT-06-2017-0156
Benefits of wonder process craft on engine valve train performance
M Usman Abdullah, Samiur Rahman Shah, M Usman Bhutta, Riaz Ahmad Mufti, Muhammad Khurram, M Huzaifa Najeeb, Waseem Arshad and Kiyo Ogawa 2018. Benefits of wonder process craft on engine valve train performance. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering. 233 (5), pp. 1125-1135. https://doi.org/10.1177/0954407018760935
Technique developed to study camshaft and tappet wear on real production engine
Waseem Arshad, Muhammad Adnan Hanif, Muhammad Usman Bhutta, Riaz Ahmad Mufti, Samiur Rahman Shah, Muhammad Usman Abdullah and Muhammad Huzaifa Najeeb 2017. Technique developed to study camshaft and tappet wear on real production engine. Industrial Lubrication and Tribology. 69 (2), pp. 174-181. https://doi.org/10.1108/ILT-06-2016-0135