Graphene Coating via Chemical Vapor Deposition for Improving Friction and Wear of Gray Cast Iron at Interfaces

Abstract

This study reports the influence of CVD-graphene on the tribological performance of gray cast iron (GCI) from the internal combustion engine (ICE) cylinder liners by performing a ball-on-disk friction tests. The graphene-coated specimen exhibited a significant reduction (∼53%) of friction as compared to that of the uncoated specimen, whereas wear resistance increased by 2- and 5-fold regarding the wear of specimen and ball, respectively. Extremely low shear strength and highly lubricating nature of graphene contribute to the formation of a lubricative film between the sliding surfaces and decreases the interaction between surfaces in the dry environment. Under the applied load, a uniform film of iron oxides such as FeO, FeO, and FeOOH is found to be formed between the surfaces. It is proposed that the graphene encapsulation with the metal debris and oxides formed between the specimens increases the lubricity and decreases the shear force. The transformation of graphene/graphite into nanocrystalline graphites across the contact interfaces following the amorphization trajectory further increases the lubricity of the film that ultimately reduces friction and wear of the material.

Tribological Behaviors of Graphene and Graphene Oxide as Water-Based Lubricant Additives for Magnesium Alloy/Steel Contacts

“…In this case, there was less water at a molecular level that could be drawn into the sliding contact interface, resulting in significantly reduced lubrication property. As for the test of the graphene nanofluids, the graphene-based tribofilm forms on the rubbing surfaces can avoid the metal-metal contact interface [ 34 ]. Therefore, there is slight enhancement in the friction-reducing and anti-wear performances of the pure water in the presence of graphene.…”

The Effect of Honing Angle and Roughness Height on the Tribological Performance of CuNiCr Iron Liner

“…(b) However, as the peak height Rpk further increased, the worn peaks introduced wear debris, which occupied the grooves, thus the originally filled lubrication oil was squeezed out. As a result, the stored oil decreased and the scuffing time was shortened [32]. Substantially, the relatively lower Rpk and higher Rk induced the better scuffing resistance.…”

Microstructure and High-Temperature Wear Performance of FeCr Matrix Self-Lubricating Composites from Room Temperature to 800 °C

“…The wear mechanism is discussed below. Temperature is an important factor for the high-temperature friction and wear behaviors of materials [24][25][26]. At elevated temperatures, metal elements and wear debris are easily oxidized in order to produce a large amount of oxides on the wear tracks (see Figure 5).…”

“…However, at high temperatures, CuO shows a lubricating effect on composites as a high-temperature solid lubricant. Erdemir et al [27] established an ionic potential (Ф = Z/r) lubricating effect model of metal oxides at elevated Temperature is an important factor for the high-temperature friction and wear behaviors of materials [24][25][26]. At elevated temperatures, metal elements and wear debris are easily oxidized in order to produce a large amount of oxides on the wear tracks (see Figure 5).…”