Characterization of Sintered Bronze–MoS₂ Composite With Solid Lubrication Effect

The most efficient method to reduce material loss and frictional energy losses is by using lubrication. An alternative is the use of solid lubrication, specifically by using solid lubricants evenly distributed in a metallic matrix, thus forming self-lubricating composites, which are capable to induce low coefficients of friction in mechanical systems. Molybdenum disulfide (MoS₂) is a very versatile solid lubricant, suitable for lubrication in critical circumstances such as vacuum, high temperatures, and pressures. Therefore, the aim of this study is to produce samples of sintered composites consisting of homogeneously distributed MoS₂ in a bronze matrix obtained by cold uniaxial pressing and to compare the wear-rates and friction coefficient between the MoS₂-free bronze and the self-lubricating composites. Different MoS₂ percentages were used to characterize the tribological properties of the composites as a function of the MoS₂ content. At the end of the experiments, it was found that samples with 20% MoS₂ did not sinter properly due to the large amount of lubricant between the bronze particles. It was also found that the mixture with 5.0 vol% MoS₂ had proper sintering, satisfactory hardness, achieved lower friction coefficient, and better material wear performance due to the optimal amount and good distribution of MoS₂ when compared with the rest of conditions studied.