Diamond like carbon coatings for tribology: production techniques, characterisation methods and applications

Abstract

There are numerous types of surface coatings available to engineers in order to improve the friction and wear resistance of components. In order to successfully use these coatings in practice, it is important to understand the different types of coatings available, and the factors that control their mechanical and tribological properties. This paper will focus on the application of diamond-like carbon (DLC) coatings in tribological applications. Thus far, DLC coatings have found broad industrial application, particularly in optical and electronic areas. In tribological applications, DLC coatings are now being used successfully as coatings for ball bearings where they decrease the friction coefficient between the ball and race, in shaving applications where they increase the life of razor blades in wet shaving applications, and increasingly in automotive applications such as racing engines and standard production vehicles.The structure and mechanical properties of DLC coatings are dependent on the deposition method and the incorporation of additional elements such as nitrogen, hydrogen, silicon and metal dopants. These additional elements control the hardness of the resultant film, the level of residual stress and the tribological properties. As diamond-like carbon films increasingly become adopted for use in industry, it is important to review the factors that control their 2 of 42 DLC Reviewproperties, and thus, the ultimate performance of these coated components in practical tribological applications.

Carbon-based solid-liquid lubricating coatings for space applications-A review

“…Figure 1 displays the development trend in the number of publications on DLC films from 1980 to 2014, and shows that the characteristics and applications of DLC films are being increasingly researched. In 1993, Möller et al [10,11] proposed a ternary phase diagram which provided a comprehensive structural and chemical description of DLC using sp 3 and sp 2 hybridized carbon and hydrogen, and in the following years several excellent review papers have covered the history, deposition techniques, characterization and applications of DLC including hydrogenated amorphous carbon (a-C:H, ta-C:H), hydrogen free amorphous carbon (a-C, ta-C), and metal or non-metal containing DLC [12][13][14]. Of most importance are the findings that DLC films provide exceptional friction reduction and wear resistance behaviors under various conditions.…”

Graphite formation in diamond-like carbon thin films

“…Образование специфической «островковой» структуры поверхности пленок [8,11] определяет трибологические [12], электри-ческие [13], гидрофобные [14] свойства. Также обнару-жено влияние на структуру и свойства тонких пленок материала подложки [11,15,16].…”

Wear properties of diamond-like carbon coatings with silicon and chromium as adhesion layer using a high frequency reciprocating rig

“…They have a wide range of applications from machining to bio-implants as its hardness may approach half that of diamond (sp 3 Carbon-Carbon bonding) (1)(2)(3)(4)(5)(6). Previous investigators working with DLC have reported wear performance of the DLC coatings using pin-on-disc, ballcratering, reciprocating ball-on-plate and ring-on-disc apparatus (7)(8)(9)(10).…”

“…However, the majority of the failures were due to the generation of high internal residual stress between the coating and substrate surfaces resulting in coating delamination (1,3,6,(24)(25)(26)(27)(28). Many authors (1,3,6,24,25) have focused on reducing delamination by adding an adhesion layer such as Silicon (Si), Titanium (Ti), Aluminium (Al) and Chromium (Cr). These adhesion layers create a transition between the substrate and the coating which reduces the likelywood of delamination (1,3,6,24,25).…”

“…Many authors (1,3,6,24,25) have focused on reducing delamination by adding an adhesion layer such as Silicon (Si), Titanium (Ti), Aluminium (Al) and Chromium (Cr). These adhesion layers create a transition between the substrate and the coating which reduces the likelywood of delamination (1,3,6,24,25).…”