All Toyota Tribological Innovation to Realize “Zeronize” and “Maximize” Society

Toyoda, Shunsuke

doi:10.2474/trol.2.19

Cited by 12 publications

(6 citation statements)

References 2 publications

(1 reference statement)

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“…This is in line nowadays with the vision of business solutions based on the philosophy referred to as "Zeronize" [1,2]. Zeronize symbolizes the efforts for the minimization of negative and adverse effects of energy conversion and/or mobility environment.…”

Section: Introductionmentioning

confidence: 59%

Slip-rolling resistance of high performance thin films and high toughness steel substrates under extreme conditions

Scholz¹,

Manier²,

Woydt³

2010

WIT Transactions on the Built Environment

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Nowadays, diamond-like carbon (DLC) coatings are mainly used in many low loaded applications such as in machine tools, computer devices and many more. Especially the automotive industry anticipates a benefit in applying such coatings in association with the lightweight construction of mechanical parts, for instance in gear components. The ulterior motive is a global performance increase regarding environmental impact and power efficiency. In recent years, the slip-rolling resistance of DLC, a-C and ta-C thin film coatings was improved considerably. In view of the mechanical application of thin film coatings, there is still room for improvements. It was experimentally shown, that a-C and ta-C coatings can be slip-rolling resistant at room temperature in unaddivated paraffin oil up to ten million cycles under Hertzian contact pressures up to P 0max = 2.9 GPa. Typically, the prime coated steel substrates were made of the hardened and tempered steels 100Cr6H and Cronidur 30. The aim of the work this to overtake these results, i.e. at higher maximum Hertzian pressures up to P 0max = 4.2 GPa. Under such extreme conditions, it is necessary to choose special steels to avoid the failure of the substrate and to permit a higher load carrying capacity of the coating-substrate-system. In consideration of the increased substrate properties, two high toughness spring steels and an ultra-high toughness aerospace steel were tested on a twin disc tribometer of the Amsler type as well as on an Optimol TwinDisc test rig under mixed/boundary conditions. Different factors such as residual stresses of the substrate, influences of the lubrication, and wear behaviour were investigated. The respective results are presented here.

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Section: Introductionmentioning

confidence: 59%

Slip-rolling resistance of high performance thin films and high toughness steel substrates under extreme conditions

Scholz¹,

Manier²,

Woydt³

2010

WIT Transactions on the Built Environment

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“…As the sliding conditions of the fuel injector and pump components are increasing in severity owing to higher contact pressure, several types of DLC coatings were evaluated to obtain higher wear resistance under the boundary lubrication in fuels. (12) The engine valve lifter is the most successful application of the DLC coating for a massproduced component because the fuel-saving effect is clearly observed when friction is reduced. In particular, the ta-C coating formed by arc ion plating via the physical vapour deposition (PVD) method has been adopted for the mass-produced gasoline engine to improve fuel economy, as shown in Fig.…”

Section: Technology Applied To Engine Componentsmentioning

confidence: 99%

Green Superlubrication by Hydrogen-Free Amorphous Carbon with Human Friendly Lubricants

2017

Sensors and Materials

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Recently, many abnormal weather phenomena have been observed throughout the world. One reason for this is thought to be increasing amount of carbon dioxide gas in the atmosphere. Fuelsaving technologies have been increasingly required, especially for automobiles, to avoid global environmental destruction by stringently reducing the amounts of carbon dioxide gas generated and global resource depletion. Additionally, poisonous components such as phosphorus, sulfur, and chlorine in industrial lubricants are required to be decreased or eliminated so that they do not harm human health. Technologies for reducing friction by using environment-friendly materials are direct ways of minimizing environmental problems and improving human health. For automotive engine lubrication, the viscosity of the engine oil has been lowered to improve fuel economy. As the viscosity of engine oil decreases, the requirement of wear resistance for sliding engine components such as the cam follower and piston is becoming stricter. Therefore, diamond-like carbon (DLC) which has several advantages, such as being harmless to the human body because it consists of mainly elemental carbon, low friction properties, high wear resistance, and high corrosion resistance, is increasingly applied to the actual sliding parts in automotive engines. In particular, hydrogen-free amorphous carbon, tetrahedral amorphous carbon (ta-C), is becoming popular for application to the valve lifters and piston rings of mass-produced gasoline engines, because it exhibits a lower friction coefficient under engine oil lubrication compared with hydrogen-containing amorphous carbon (a-C:H). Additionally, ta-C shows superlubricity with human-friendly lubricants, such as oleic acid and glycerol. In this article, recent topics in the technology for applying DLC coatings onto automotive engine components are reviewed. The properties of reducing friction for each application are discussed briefly. The effect of engine oil additives on the friction properties of DLC coatings is also explained. Then, the superlowfriction properties achieved by combining DLC coatings and environment-friendly lubricants are introduced as a promising technology for future engine components. A superlow friction coefficient below 0.01 was obtained by a self-mated ta-C coating lubricated with oleic acid; a-C:H coating and the noncoated bearing steel (SUJ2) did not function well. These results suggest that automotive engine fuel economy can be improved markedly by using completely environmentfriendly materials. Recent fundamental research on the mechanism of superlubrication is introduced briefly. Judging from these advanced technical results, DLC coating technologies to 772

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“…The high wear resistance and high friction coeffi cient of the a-C:H:Si coating resulted in a compact clutch system. In addition, the fact that the friction coeffi cient of this coating has a positive slope relative to increasing sliding velocity provides higher shudder resistance [ 12 ].…”

Section: Application To Engine Componentsmentioning

confidence: 99%

Overview of DLC-Coated Engine Components

Kano

2015

Coating Technology for Vehicle Applications

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Fuel-saving technologies have become more important in recent years, especially for automobiles, in order to avoid global environmental destruction and global resource depletion. In addition, the use of toxic elements such as phosphorus, sulfur, and chlorine in industrial lubricants must be decreased or eliminated. Technologies for reducing friction with environmentally friendly materials are direct ways of addressing environmental problems. Diamond-like carbon (DLC) coatings are increasingly being applied to the sliding parts of automotive engines, among other applications, to reduce friction and wear. These coatings have several advantages, including their harmless nature to the human body because they consist mainly of carbon, low friction, high wear resistance, and strong corrosion resistance.This chapter discusses recent topics concerning the application of DLC coatings to automotive engine components. DLC coatings have already been successfully applied to the valve lifters and piston rings of mass-produced gasoline engines. The resultant effect on reducing friction in each application is described briefl y. The effect of engine oil additives on the friction and wear properties of DLC coatings is also explained. Promising technologies for applying DLC coatings to future engine components are then presented.The fi rst topic discussed in this regard is the application of DLC coatings to aluminum alloys with suffi ciently strong adhesion for obtaining high wear resistance. This can be accomplished by shot peening the aluminum alloy substrate with fi ne tungsten particles. A DLC coating deposited on A2017 and A5052 aluminum alloys (Japanese Industrial Standards) with this new process showed 40-80 % higher wear resistance and adhesion strength than DLC coatings formed by conventional processes. As a result, a DLC-coated aluminum alloy piston displayed superior wear resistance compared with that of a noncoated piston in a short-term engine fi ring test.The second topic concerns super-low friction properties obtained by combining a DLC coating with an environmentally friendly lubricant. A super-low friction coeffi cient below 0.01 was obtained with a self-mated ta-C (tetrahedral amorphous carbon) coating lubricated with oleic acid, whereas an a-C:H (amorphous hydrogenated carbon) coating and bearing steel (JIS-SUJ2) did not display such a large

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All Toyota Tribological Innovation to Realize “Zeronize” and “Maximize” Society

Cited by 12 publications

References 2 publications

Slip-rolling resistance of high performance thin films and high toughness steel substrates under extreme conditions

Slip-rolling resistance of high performance thin films and high toughness steel substrates under extreme conditions

Green Superlubrication by Hydrogen-Free Amorphous Carbon with Human Friendly Lubricants

Overview of DLC-Coated Engine Components

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