Studies on Copper-Coated Boron Carbide Particle-Reinforced Copper-Matrix/Graphite Self-Lubricating Composite Materials

Resumo

In this study, copper-coated (Cu-coated) boron carbide (B₄C) particles were successfully prepared by electroless Cu plating onto B₄C particle surfaces. These Cu-coated B₄C particles were combined with Cu-coated graphite particles and Cu powder, which were then used to prepare a new type of Cu-matrix self-lubricating composite by powder metallurgy. Uncoated B₄C particles were used to prepare corresponding composites and all composites characterized by phase composition, microstructure, density, porosity, hardness, compressive yield strength, and friction wear. The results showed that Cu-coated B₄C particles improved wettability between the particles and matrix and possessed increased interface-bonding strength with the matrix. With the same B₄C content, Cu-matrix/graphite composites reinforced by Cu-coated B₄C had lower porosity and wear resistance, as well as higher hardness and compressive strength, than composites reinforced by uncoated B₄C. Considering the wear and friction coefficients, composites containing 0.5 wt % Cu-coated B₄C exhibited better friction and wear resistance properties.