Sintered Steels Containing Solid Lubricants: An Alternative for Lubricated Systems

Powder metallurgy is an alternative to produce microstructures of materials able to reduce friction and wear of mechanical systems, consequently, improving its efficiency and mitigating CO2 emissions. In this work, self-lubricating composites were produced using a Fe-based matrix (Fe+0.5Si+4Ni+0.5Mo+0.2Mn) and solid lubricants (1h-BN+6.5graphite) dispersed through the bulk. Thermodynamics aspects were considered to avoid the diffusion of solid lubricants during the sintering and kept them as solid lubricant reservoirs. The samples were characterised in terms of microstructure and mechanical properties. Additionally, its tribological behaviour was analysed in dry and oillubricated conditions (ball-on-cylinder tribopair). Wear marks were analysed to identify the formation of tribolayers and the interaction of composite with the oil and atmosphere. The results indicate a material with outstanding mechanical properties (276.1±50.55 MPa UTS, 770±65 HV0.05) able to reduce friction and wear due to the formation of tribolayers in both conditions.