Optimisation of microstructure and wear properties of porous Fe-Cu bearing materials

Optimising Fe-Cu porous bearing materials is essential for improving durability and wear resistance in automotive systems. However, the combined influence of mechanical alloying and sintering processes on their microstructural properties and tribological response has not been systematically clarified. In this study, a Fe-20Cu alloy was fabricated via mechanical alloying for 4, 8, 12 and 16 h, followed by sintering at 800, 900 and 1000 °C. X-ray diffraction revealed progressive peak broadening and structural refinement with increasing milling time, while scanning electron microscopy indicated a transformation from coarse, heterogeneous particles (4 h) to refined, compact structures after extended milling. Sintering improved interparticle bonding and densification, with the most uniform and consolidated microstructure obtained at 1000 °C. Energy-dispersive X-ray mapping confirmed enhanced Fe-Cu mixing with minor oxide enrichment. Testing demonstrated the lowest wear rate (1.45 × 10–4 mm3/m) and the highest density (7.22 g/cm3) for the sample obtained after 12 h of milling and sintering at 1000 °C. Excessive milling (16 h) slightly lowered densification due to particle reagglomeration. Overall, 12 h of milling combined with sintering at 1000 °C provides the optimal balance between densification, microstructural refinement and wear resistance, confirming Fe-Cu porous alloys as promising candidates for high-performance applications.