Effect of Powder Metallurgy Process and its Parameters on the Mechanical and Electrical Properties of Copper-Based Materials: Literature Review

As the world is shifting towards renewable sources of energy, the demand for copper is increasing due to its excellent electrical and corrosion resistance properties. Although, because of low strength and wear resistance, the use of pure copper is quite limited. Various reinforcing materials are added to the Cu matrix to fabricate high-strength and wear-resistant copper matrix composites. Powder metallurgy is the most commonly used metal matrix composite fabrication method for Cu-based materials. Properties of a powder metallurgy product depend on the process parameters such as compaction pressure, sintering temperature, sintering time, type and rate of reinforcement, size of matrix and reinforcing elements, etc. In the present work, the influence of the above-mentioned parameters on mechanical and electrical properties of copper-based materials produced by the powder metallurgy method is reviewed in detail. The literature survey revealed that SiC, graphite (Gr), TiC, and graphene (Gn) are the most commonly used reinforcement additives in the Cu matrix for improvement of the strength and wear resistance of Cu-based materials. It has been established that the strength and wear resistance increase after the addition of the mentioned reinforcers, although the electrical conductivity decreases. For enhanced mechanical and electrical properties, a 4-6% weight fraction of micron-sized reinforcers, such as SiC, TiC, and graphite, and a 0.25-1% weight fraction of nano-sized reinforcers, such as CNTs and graphene, are considered the optimum reinforcement range for the Cu-matrix. Small particle size of 3-5 mu m of matrix material (Cu) improves mechanical and electrical properties. The size of nano-reinforcers, such as CNTs, should be sufficiently larger (30-50 nm) to avoid agglomeration. Besides, factors contributing to better properties are the optimum range of compaction pressure of 550-650 MPa, sintering temperature of 800-900 degrees C, and sintering time of 60-90 min.