Structural evolution of a carbon nanotube film under sliding wear: From a forest to a self-lubricating nanocomposite tribofilm

Auteurs

de Souza Lamim T., Martinez D.M., Pigosso T., Klein A.N., Bendo T., Binder C.

Référence

Carbon, vol. 238, art. no. 120224, 2025

Description

This work investigates the structural transformation of a vertically aligned carbon nanotube (VACNT) film under sliding wear by systematically analyzing the self-lubricating tribofilm. The VACNT film was grown on steel by plasma-induced metal dusting. The VACNT solid lubricant ability was assessed by reciprocating sliding tribotests. Scanning electron microscopy monitored the progressive wearing of the film, while Raman spectroscopy evidenced the progressive reduction of the graphenic material crystallites in the tribofilm. The self-lubricating tribofilm is composed by a nanocomposite structure consisting mainly of Fe3C nanoparticles embedded in a carbon matrix, as revealed by high resolution transmission electron microscopy, electron diffraction, fast Fourier transform and its inverse. These nanoparticles are associated with the catalyst particles of the nanotubes. During the wear process, they become more spherical, and their diameter decreases. The structural aspect of the carbon matrix varies according to the depth within the tribofilm. The top and innermost regions of the tribofilm exhibit the largest turbostratic domains, with the graphene layers horizontally oriented at the top, while remaining vertically oriented and attached to the interface at the bottom region. Furthermore, the central region consists of turbostratic nanodomains surrounded by amorphous carbon, suggesting a more significant tribo-degradation process in this area.

Lien

doi:10.1016/j.carbon.2025.120224