Tribologically induced nanostructural evolution of carbon materials: A new perspective

Abstract

Carbon-based solid lubricants are excellent options to reduce friction and wear, especially with the carbon capability to adopt different allotropes forms. On the macroscale, these materials are sheared on the contact along with debris and contaminants to form tribolayers that govern the tribosystem performance. Using a recently developed advanced Raman analysis on the tribolayers, it was possible to quantify the contact-induced defects in the crystalline structure of a wide range of allotropes of carbon-based solid lubricants, from graphite and carbide-derived carbon particles to multi-layer graphene and carbon nanotubes. In addition, these materials were tested under various dry sliding conditions, with different geometries, topographies, and solid-lubricant application strategies. Regardless of the initial tribosystem conditions and allotrope level of atomic ordering, there is a remarkable trend of increasing the point and line defects density until a specific saturation limit in the same order of magnitude for all the materials tested.

Preparation and Tribological Performance of Multi-Layer van der Waals Heterostructure WS2/h-BN

“…The B and N in the transfer film derived from the h-BN in the multilayer vdWH WS2/h-BN where the W and S were attributed to WS2 [32]. As the sliding distance increased from 200 m to 2000 m, the content of WS2 and h-BN increased from 24.57 wt% to 57.99 wt%, indicating that a continuous transfer film composed of the multi-layer vdWH WS2/h-BN formed [4,[32][33][34]. During the friction process, the multi-layer vdWH WS2/h-BN deposits on the surface of the stainless steel and forms a continuous transfer film, thereby reducing friction and the wear of the contact interface [35].…”