Effect of graphite concentration on the tribological performance of alumina coatings

Smart Tribological Coating

“…Self-lubr cat ng tr bolog cal coat ngs feature mater al compos t on or structural arch tecture that ntr ns cally reduces surface fr ct on and wear [103][104][105]. Th s s done us ng a self-conta ned nherent self-lubr cant system such as graph te [106] and Molybdenum D sulf de (MoS2) [107].…”

Effect of Spraying Power on the Tribological Properties of Alumina and Alumina-Graphite Coatings

“…The increase in torch power slightly reduced the number of microcracks. It was observed that the formation of a self-lubricating graphite layer in the contact zone between the coatings and counterbody materials decreases the friction coefficient and could reduce the wear rate of the composites or composite coatings [36][37][38][46][47][48][49]. However, the addition of softer materials (e.g., graphite) in ceramic coatings, especially in high concentrations, reduces their hardness, fracture toughness, and cohesion values between the individual splats.…”

“…It was found that the addition of a low amount of graphene nanoplatelets (up to 3 wt.%) and graphene oxide (GO) enhanced the specific wear rate and reduced the friction coefficient of alumina-graphene composite coatings [32][33][34]. Our previous investigations [35][36][37] demonstrated that the friction coefficients and specific wear rates of alumina-graphite coatings are dependent not only on the concentration of graphite in the alumina feedstock powder but also on the type of Al 2 O 3 and graphite powders used. It was demonstrated that the increase in spraying distance enhanced the friction coefficient of alumina-graphite coatings from 0.34 to 0.38 [36].…”

“…It was demonstrated that the increase in spraying distance enhanced the friction coefficient of alumina-graphite coatings from 0.34 to 0.38 [36]. Meanwhile, the variation of the graphite concentration in the feedstock powders allowed for manipulation of the friction coefficient and wear rate of alumina-graphite coatings [35,37]. Al 2 O 3 coatings are generally found to exhibit high wear rates and friction coefficients, but with the addition of a solid lubricant such as graphite, extrinsic modifications can be made.…”

Tribological characteristics of friction stir processed graphite and tin/LM24 surface composites

“…However, the wear resistance increased regardless of the reduction in the hardness owing to the favorable role of graphite in the tribolayer formation [21][22][23]. Marcinauskas et al [24] found that the COF was reduced when the graphite-Al2O3 coating on the steel had a limited graphite content. A higher graphite content tends to reduce the hardness of the composite coating, which in turn increases the possibility of Al2O3 pull-out.…”