Influence of Carbon Nanotube (CNT) Addition and Post-Baking Process on the Mechanical and Electrical Properties of Carbon-Copper Composites

Abstract:

Pantograph slide materials demand excellent mechanical and electrical properties for rail applications. Carbon-copper (C-Cu) composites combine the high electrical conductivity of copper with lightweight and wear-resistant traits of carbon. Using palm kernel shells (PKS), a palm oil industry by-product, promotes sustainability but presents challenges in achieving uniform distribution and performance retention. This study examined PKS and graphite as carbon sources in C-Cu composites enhanced with carbon nanotubes (CNT), focusing on optimising mechanical and electrical properties for pantograph slides. However, CNT is known for its difficulty in achieving optimum dispersion in composites, as strong van der Waals forces cause aggregation, uneven distribution, and porosity, thereby reducing the electrical and mechanical properties. Balancing carbon content, CNT reinforcement, copper, and resin matrix is crucial to prevent conductivity loss and structural weaknesses. Varied CNT content (1wt% to 5wt%) was analysed for its impact on hardness, transverse rupture strength (TRS), and electrical resistivity of the C-Cu composite. Fabrication involved material mixing, cold pressing, warm compaction (150°C, 490 kN, 5 minutes), and post-baking process (250°C, 4 hours). The 2 wt% CNT sample achieved superior results, including 102.5 HRR hardness, 37.63 MPa TRS, and 32 µΩ.m resistivity before post-baking, due to excellent CNT dispersion. Post-baking enhanced bonding and mechanical properties but raised resistivity by altering conductive pathways. Poor dispersion of CNT at contents more than 3 wt% led to agglomeration and inferior properties. The findings highlight the critical role of CNT dispersion and the post-baking process in achieving optimal composite performance to maximise CNT potential. These results are comparable to commercial pantograph slides, contributing to the development of high-performance materials for rail applications.

• Periodical: Solid State Phenomena (Volume 392)
• Pages: 53-62
• DOI: https://doi.org/10.4028/p-Fjp03X
• Online since: April 2026
• Authors: Fazira Suriani Mohamed Fadzil*, Koay Mei Hyie, Normariah Che Maideen, Nor Azirah Mohd Fohimi, Nor Suhada Abdullah, Muhammad Afiq Abd Mutalib
• Keywords: Carbon Nanotube, Carbon-Copper, Dispersion, Post-Baking, Warm Compaction

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