Development and Characterization of Brass-Graphite (Sn) Composites for Bush and Bearing Applications

This research focuses on the characterization of the mechanical and microstructural properties of stir-cast brass-based composite containing 12% Tin (Sn) and 2%, 4%, 6%, 8%, and 10% Graphite (Gr) as reinforcement. The goal was to establish the impact of Graphite on the properties of ultimate tensile strength (UTS), impact strength, hardness, and microstructure of composites to find out the ideal reinforcement percentage. The characterization of the improved brass composite showed that the best overall result was achieved when 6% Graphite was added, indicating a 14% improvement in UTS, a 31.4% increase in impact strength, and an 11.8% increase in hardness compared to the brass. SEM microstructure test supported by the result of reinforcement localization of Graphite at 6% and EDS test supported the presence of reinforcements in the matrix. Their properties decreased when the graphite content exceeded 6%, due to clustering and porosity. As a result, this study reveals that the use of brass-graphite composites, with 6% Graphite as the best option for self-lubricating bush and bearings, where issues related to strength, hardness, and wear are highly valued.