@article{Ji2026, 
author = {Dehui Ji and Fulin Mao and Haihong Wu and Zhinan Zhang and Siyang Chen and Jingyi Wang and Mingxue Shen},
title = {From sparks to nanostructures: How arcing induces C/Cu wear and microstructural evolution},
year = {2026},
journal = {Friction},
keywords = {Current-carrying friction and wear, C/Cu, arc erosion, erosion products, onion-like carbon, graphitization},
url = {https://www.sciopen.com/article/10.26599/FRICT.2026.9441289},
doi = {10.26599/FRICT.2026.9441289},
abstract = {Most electric locomotives currently draw power from overhead contact lines. As train speeds continue to increase, irregularities in the contact wire cause system vibrations, leading to frequent pantograph-catenary arc discharges. The presence of arcing imparts distinctive friction, wear, and erosion product characteristics to the current-carrying friction process. Carbon/copper materials subjected to arc erosion exhibit significant differences in surface morphology and physicochemical properties compared to those resulting from pure mechanical wear. In this study, the phenomenon of arcing due to contact wire irregularities under simulated service conditions was investigated to examine the effects of arcing on the current-carrying wear behavior of carbon strips in pantograph-catenary systems and the resulting erosion products. The results indicate that current magnitude is positively correlated with the friction coefficient, temperature, arc ignition rate, and arc energy. Increased current shifts the dominant wear mechanism from abrasive wear to arc-induced erosion. Moreover, higher current levels promote the emission of particles, especially small-sized ones, while the proportion of medium and large-sized particles also increases. However, sustained intense arcing slightly reduces the total particle count due to material sublimation. The microscopic morphology of the particles is predominantly characterized by onion-like carbon spheres encapsulated with copper nanoparticles and multi-walled carbon nanotubes. Additionally, arc erosion significantly enhances the crystallinity and graphitization degree of the carbon material. This study provides an in-depth analysis of arc-induced erosion products and contributes to the theoretical understanding of the microstructural evolution and graphitization behavior of carbon materials under arcing conditions.}
}