Effect of silver plating and sintering temperature on the microstructure and mechanical properties of carbon fiber reinforced Cu matrix composites

Abstract

Recycled carbon fibers are primarily utilized as reinforcement in the production of composite materials, and they have steadily become a hot topic in the twenty-first century. However, the presence of large amount of residual resin, crack damage and graphitized surface layer on the surface of recycled carbon fibers leads to the reduction of their mechanical properties. In this study, Cu matrix composites reinforced with carbon fiber were created using the spark plasma sintering process at 700–850 °C sintering temperature. The surface coating treatment was done to recycled carbon fiber in order to enhance the interfacial bonding between the carbon fiber and Cu matrix, and the ideal surface Ag plating parameters were investigated and established. Results have shown that the Ag coating on the fiber surface diffuses at different sintering temperatures, forming a Ag–Cu solid solution, which has a solid solution-strengthening effect on the substrate. When the sintering temperature is below 800 °C, some Ag atoms will precipitate out of the matrix, forming a small amount of Ag precipitation phase. As the sintering temperature increases, the tensile strength of the composite increases and then decreases, the compressive strength gradually decreases and the flexural strength gradually increases.

Keywords

• Carbon fiber surface modification
• Spark plasma sintering
• Composite