Enhanced DLC wear performance by the presence of lubricant additives

Abstract

Lubricant additives play significant role for reducing friction and wear of mechanical elements. The additives presented in 5W30 oil were developed for metal surfaces. However, they have been used in engine pieces covered with DLC coatings because they also offer the potential to reduce friction losses and wear in automotive applications. The friction and wear tests were carried out by using a UMT-CETR ball-on-disk tribometer in rotational mode under 5W30 synthetic oil at 100 °C. The X-ray photoelectron spectroscopy (XPS) showed the presence of Mo and S in the wear tracks. These elements are from decomposition of ZDDP and MoDTC additives producing MoS 2 in DLC surface, which offers enhanced durability by low wear rate.

Effect of ZnDTP triboflim's morphology on friction behaviors of DLC coatings: Tribofilm characterization by 3D scanning electron microscope observation

“…Diamond-like carbon (DLC) coatings have been extensively researched in recent years to further our understanding of their properties and increase the efficiency in their use to reduce energy toward a sustainable society. Their properties (such as high hardness, low friction coefficient, wear resistance and chemical inertness (Clausing et al, 2012;Erdemir, 2006;Robertson, 1992;Tasdemir, 2013)) or their tribological behaviors with different oil additives (Costa et al, 2011;Kosarieh et al, 2016;Renman, 2012) have been investigated over the years. Among additives for lubricating oils being used since 1920s, some are chemical compounds known to be able to absorb and/or react with the sliding surfaces to produce low-shear-strength tribochemical reaction layers that prevent direct contact between the sliding surfaces and are often used to reduce wear in the boundary-lubricated regime.…”

Low Friction Property of Diamond-Like Carbon Coating Films and Oxygen Transmission Ratio of Amorphous Carbon Films Deposited by Advanced Coating Processes

“…This ultra-low friction is thought to be generated by forming very thin and weak tribofilm at the mixed lubrication condition. [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] Martin et al proposed the possible mechanism of the super low friction was the forming water layer by the tribochemical reaction between ta-C and glycerol. [28][29][30][31][32][33] In this paper, the formation of water and acid was indicated as one possible chemical reaction for glycerol, as shown in Fig.…”

Electrochemical Performance of Porous Diamond-like Carbon Electrodes for Sensing Hormones, Neurotransmitters, and Endocrine Disruptors

“…Diamond-like carbon (DLC) is an interesting metastable form of amorphous carbon that contains a mixture of tetrahedral (sp 3 ) and trigonal (sp 2 ) carbon hybridizations in varying amounts depending on its deposition conditions. Although DLC can be deposited at low (<200 °C) substrate temperature, , it exhibits many of the extreme properties of crystalline diamond . Among those properties are chemical inertness, optical transparency, high mechanical hardness, low friction coefficient, and very high electrical resistance, which together make DLC very attractive for use as a protective coating. − However, unmodified DLC films are electrically insulating, which prevents their application in several fields, including electroanalysis.…”