ME-C:H coatings in motor vehicles

Gåhlin, Rickard; Larsson, Mats; Hedenqvist, Per

doi:10.1016/s0043-1648(01)00565-8

Cited by 151 publications

(73 citation statements)

References 13 publications

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“…It was also found that variations in friction coefficient with sliding distance were not related with this transition in wear rate and a transfer film was rapidly developed on the uncoated ball surface. Gåhlin et al reviewed and discussed ME-C:H coatings applications in motor vehicles [7]. They found out that over time, Me-C:H coatings contributed to significant decrease of friction and dramatic increase of wear resistance and resistance to seizure in these applications.…”

Section: Introductionmentioning

confidence: 99%

Development of DLC coating architectures for demanding functional surface applications through nano- and micro-mechanical testing

Beake

Liskiewicz

Vishnyakov

et al. 2015

Surface and Coatings Technology

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DLC coatings can combine high hardness with low friction. However, they are often deposited with high levels of intrinsic stress and display low adhesion strength resulting in poor performance in demanding applications. A highly topical challenge is to develop advanced DLC coatings capable of withstanding more demanding applications in the automotive, cutting tools, MEMS and oil and gas sectors. The results from several nanomechanical and tribological test techniques -nanoindentation, nano-scratch and nanofretting (nano-wear) -can be used together to aid the design of DLC coating architectures for enhanced durability in specific applications. In this study the behaviour of multilayered DLC coatings (Cr/W-C:H/a-C:H, Cr/W-C:H/Si-a-C:H) was compared to that of CrN/a-C:H:W (WC/C). We have previously reported that in nano-wear tests the coating with the highest hardness and H/E displayed greater wear resistance [T.W. Liskiewicz et al, Surf. Coat.Technol. 237 (2013) 212]. By employing nano-and micro-scale tribological testing with probes of differing sharpness it is possible to change the sensitivity of the test to probe the response of the coating top layer or the entire multilayer coating-substrate system. In the nano-scratch tests using a spherical indenter with a 5 m end radius the maximum stresses are located well within the top layer of the multilayer coatings and consequently the mechanical properties of this top layer dominate the nano-tribological behaviour. In the micro-scratch using a 25 m spherical probe the stress field extends further towards the sublayers and steel substrate and consequently the behaviour is completely different. Under these conditions the coating with the lowest hardness and H/E showed improved performance with higher critical loads for cracking and total coating failure. High resolution SEM imaging has been used to investigate this further. A simple contact model strongly suggests that cracking and failure events occur on the harder coatings when the maximum von Mises stress was located close to the interfaces in the multilayer systems.3

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Section: Introductionmentioning

confidence: 99%

Development of DLC coating architectures for demanding functional surface applications through nano- and micro-mechanical testing

Beake

Liskiewicz

Vishnyakov

et al. 2015

Surface and Coatings Technology

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“…DLC fulfils these requirements and has been tested on a large number of automotive components: gears, wrist pins, valve filters and fuel injector parts. Specifically, serial production of metalcontaining DLC (Me-DLC) coatings by physical vapor deposition has been performed on diesel injection systems [Gahlin et al, 2001]. The modern high-pressure injection systems were developed thanks to DLC.…”

Section: Applicationsmentioning

confidence: 99%

Tribological Properties of Fluorinated Amorphous Carbon Thin Films

Rubio‐Roy¹,

Corbella²,

Andújar³

et al. 2011

New Tribological Ways

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“…On the subject of wear-resistant coatings, an overview of one manufacturer's DLC coatings for automotive applications is given by Gahlin et al 25 A paper by Erdemir et al…”

Section: Wear-resistant Coatingsmentioning

confidence: 99%

Near-frictionless carbon coatings for spark-ignited direct-injected fuel systems. Final report, January 2002.

Hershberger¹,

Öztürk²,

Ajayi³

et al. 2002

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EXECUTIVE SUMMARYThis report describes an investigation by the Tribology Section of Argonne National Laboratory (ANL) into the use of near-frictionless carbon (NFC) coatings for spark-ignited, direct-injected (SIDI) engine fuel systems. Direct injection is being pursued in order to improve fuel efficiency and enhance control over, and flexibility of, spark-ignited engines. SIDI technology is being investigated by the Partnership for a New Generation of Vehicles (PNGV) as one route towards meeting both efficiency goals and more stringent emissions standards. Argonne's approach to these friction and wear issues was to investigate the applicability of NFC to fuel system parts. In collaboration with Delphi Automotive Systems and BP Amoco plc, Argonne carried out two tasks: optimize the deposition of NFC onto standard flats and balls as well as production fuel injectors, and perform both industry-standard lubricity tests and customized wear tests designed to simulate the engine environment. These tests were performed with several gasolines and other fuels, and the NFC performance was compared to that of uncoated parts and other commercially available coatings, all applied to production fuel injectors. Finally, to understand the wear mechanisms, Argonne applied advanced characterization techniques to the worn and unworn coatings, the steel against which they wore, and the wear debris. The industry-standard lubricity tests included the Falex ball-on-three-disc (BOTD) test, while the customized wear testing was performed in a sealed reciprocating system designed to perform fretting wear tests. Long-duration reciprocating tests were performed with a ii total sliding distance of 2 km in order to determine the steady-state performance of the NFC coatings. The worn surfaces were examined by 3D optical profilometry to determine wear rates.The advanced characterization methods applied included Raman spectroscopy and laser scanning measurement of residual stresses in the NFC coatings.In the customized reciprocating tests, comparisons between two varieties of NFC and three commercially available diamondlike carbon (DLC) coatings showed that the NFCs gave consistently high performance and were generally the best choice for reducing friction and wear, although one of the commercial DLCs achieved performance comparable to the NFCs in several individual tests. The other commercial DLCs displayed poor performance under certain conditions. In dry or ethanol-lubricated wear, NFC6 performed the best; when subjected to E85 or M85 fuel, the commercial DLC gave the best results; and NFC2 displayed the lowest friction and wear rate of the three in regular gasoline, the most relevant condition for fuel injector applications. NFC2 reduced friction in all the liquids tested, compared to tests of uncoated materials in the same fluids; NFC6 did also but not to as great an extent.The long-duration tests designed to determine the ultimate wear lifetime of the NFC coatings on injectors in current-and next-generation gasolines showed that NFC6 pro...

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ME-C:H coatings in motor vehicles

Cited by 151 publications

References 13 publications

Development of DLC coating architectures for demanding functional surface applications through nano- and micro-mechanical testing

Development of DLC coating architectures for demanding functional surface applications through nano- and micro-mechanical testing

Tribological Properties of Fluorinated Amorphous Carbon Thin Films

Near-frictionless carbon coatings for spark-ignited direct-injected fuel systems. Final report, January 2002.

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