Wear analysis of hydrogen-free diamond-like carbon coatings under a lubricated condition

Influence of wetting and thermophysical properties of diamond-like carbon coatings on the frictional behavior in automobile gearboxes under elasto-hydrodynamic lubrication

“…Against this background, surface properties of lubricated rolling-sliding contact partners periodically or continuously operating under boundary and mixed friction conditions and the interactions with the lubricant can be considered as the key factors influencing the friction behavior. The application of diamondlike carbon (DLC) coatings on machine elements deposited by means of physical vapor deposition (PVD) and plasma enhanced chemical vapor deposition (PECVD) is a common approach to meet the challenges of friction reduction, efficiency improvement and wear protection in various tribological systems [4][5][6][7][8][9][10][11]. This particularly includes piston rings, tappets, camshafts and plungers of injection systems and gearboxes [2,[9][10][11][12][13][14][15].…”

“…This particularly includes piston rings, tappets, camshafts and plungers of injection systems and gearboxes [2,[9][10][11][12][13][14][15]. With regard to highly loaded rolling-sliding contacts as gears and rolling bearings, DLC coatings contribute to wear reduction due to their favorable effect on the load capacity in terms of pitting, scuffing and micro-pitting [4][5][6][7]. Due to their properties in terms of friction reduction and wear protection, DLC coatings are typically used in dry-running or under boundary and mixed friction conditions [4,5,7,8,11,[16][17][18][19][20][21][22].…”

“…With regard to highly loaded rolling-sliding contacts as gears and rolling bearings, DLC coatings contribute to wear reduction due to their favorable effect on the load capacity in terms of pitting, scuffing and micro-pitting [4][5][6][7]. Due to their properties in terms of friction reduction and wear protection, DLC coatings are typically used in dry-running or under boundary and mixed friction conditions [4,5,7,8,11,[16][17][18][19][20][21][22]. But application of these coatings in the fluid friction regime comes into focus of research and development.…”

Influence of Wettability and Mechanical Properties on Tribological Performance of DLC Coatings under Water Lubrication

“…An average of 5 measurements was used to determine the hardness of the DLC coating in order to obtain a good statistical representation. In order to avoid surface and substrate effect, the depth of indentation was set at 100 -200 nm which was lower 10% of the layer thickness [24]- [26]. Figure 10 shows the load-displacement curves of DLC coatings by nanoindenter.…”

Coating‐lubricant combination for improving tribo‐system performance

“…Additive (dopant) in coating influences the tribological properties when lubricated with mineral oil . Deposition process of DLC can also influence the tribological properties of the coating lubricated with fully formulated oils . Improvements in tribological properties by lubricant additives are being currently examined, mostly using ZnDTP with focus on the formation and structure of boundary film .…”