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Tribological C Behavior of Graphite/Brass Composite opper/graphite composites are known for their high electrical conductivity and good wear resistance. By adding graphite, it is possible to get improved mechanical or sliding properties. These composites are one of the most acceptable materials used for low-voltage circuit breakers.1-2 Various materials have been used as a brush; and most often the graphite-based materials, such as arti��cial graphite, natural graphite, resin-bonded graphite, and metal-graphite composites, have been employed in stable signals and power transmission through the sliding contacts.3-4 The preparation method chosen depends upon the required composition, manufacturing cost, and industrial apZohair Sarajan, Yazd Branch, Islamic Azad University, Yazd, I.R of Iran plication. Copper and its alloys are frequently FarZad jaaFari jouZan, The Holy Prophet Higher Education Complex, used for general-purpose applications, Shahid Sadughi Technical University, Yazd, I.R of Iran although noble metals are often employed in small size applications.5-7 Other specialty metals such as bronze, cupronickel, and Monel��� (Ni, 25~40% Cu) are also used for high-strength and hightemperature applications. The introduction of a third component into a binary metal alloy with a miscibility gap in the liquid state can significantly shift the temperature and concentration boundaries of the region of immiscibility. The chemical bonding states of C/Cu interfaces have been investigated using the first-principles molecular orbital method with model clusters. In Cu-Fe alloys, the miscibility gap in the liquid state appears as a result of strong supercoiling.8-10 It is known that small additions of carbon and silicon (~0.5%) to Cu-Fe alloys displace the immiscibility dome toward higher temperatures, into the region of existence of an equilibrium melt.11-12 Another problem is the modi��cation of already-formed particles. Depending upon the metal, particle size, the Graphite/brass composite was fabricated by adding graphite/Cu/Zn compact powder into molten brass using the stir casting technique. Its tribological behaviors against a brass disk were studied under the simulated actual conditions. Te experimental results showed that the 7 to 9 wt% graphite creates the best wear resistance in high-pressure applications. A continuous Zn layer successfully covered the surface of the graphite particles, which could contribute to the improvement of interfacial wettability between graphite and brass. 62 MATERIALS PERFORMANCE March 2013 ��� Trade name. NACE International, Vol. 52, No. 3