Advanced Graphite/Metal Composite Materials for High Voltage Automotive Applications

This study presents the development and characterization of four graphite-based/metal composite materials suitable for high-voltage applications in the automotive industry, specifically for use as current collector materials in trolleybuses. The composites were processed utilizing different combinations of graphite types (granulated natural graphite, natural graphite flakes, and graphite chemically coated with copper), binders (coal tar pitch and commercial resin Novolac), and metallic additives (electrolytic Cu powder, Sn powder, and MoS2). The structural, mechanical, and functional properties of the four composite materials were investigated. The composites exhibited similar hardness values, but their coefficients of friction differed due to variations in chemical composition and processing methods. In terms of mechano-electrical wear, despite their similar hardness and mechanical strength, the materials exhibited different wear patterns based on their electrical conductivity and voltage drop. The novelty of this study lies in the introduction of a new technological process for obtaining carbon/metal composite materials used in the manufacture of sliding contacts for current collector heads. The suggested materials are anticipated to reduce the wear on the electrical wire, thereby lowering maintenance expenses. The most suitable material was selected for further development by the end beneficiary.