Copper–Graphite Based Powder Metallurgy Product and Its Mechanical Properties

Powder metallurgy is one of the most efficient and economical manufacturing processes for producing metal matrix composites with improved physical and mechanical properties. In the present research work, copper–graphite composites were fabricated using the powder metallurgy route in order to study the effect of graphite reinforcement on the mechanical properties of copper. Copper powder was selected as the matrix material due to its excellent thermal and electrical conductivity, while graphite powder was used as reinforcement because of its lubricating properties and low coefficient of friction. Three different compositions were prepared for experimental investigation. The first specimen consisted of pure copper powder, the second specimen contained copper reinforced with 2% graphite powder, and the third specimen contained copper reinforced with 4% graphite powder. The powders were accurately weighed and mixed thoroughly to ensure homogeneous distribution of graphite particles within the copper matrix. The mixed powders were compacted using a hydraulic press under high pressure to obtain green compacts. These compacts were subsequently sintered in a furnace at elevated temperature to achieve proper bonding between the particles. The fabricated specimens were subjected to hardness testing and compression testing using a Universal Testing Machine (UTM). The hardness values and compressive strength of the specimens were recorded and analyzed. Experimental results revealed that the addition of graphite reduced both hardness and compressive strength due to the soft and lubricating nature of graphite. However, the graphite reinforcement improved the self-lubricating behavior of the composite and enhanced its suitability for applications involving sliding and frictional contact. The study demonstrates that copper–graphite composites fabricated through powder metallurgy are suitable for applications such as electrical brushes, bearings, bushings, sliding contacts, and current collectors where lubrication and conductivity are essential.