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Item type:Publication, Access status: with files , Fabrication of iron-based multiporous structures by combining in-situ reduction with sintering(Elsevier, 2026-02-04); 37 49 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Improvement of the tribological properties of iron-based self-lubricating composites by modification of the sintering atmosphere(Kyōkai, 2025-03-15); ; In this work, powder compaction and solid-state sintering are employed to fabricate iron-based self-lubricating composites containing MoS2 and graphite. Previous studies have shown that MoS2 reacts with iron matrices during sintering, making the production of Fe-MoS2 composites challenging. We hereby demonstrate that a modification in the sintering atmosphere improves the composites' tribological properties due to a synergic effect of retardation of the solid-state reaction and increase of the matrix microhardness related to the nitrogen intake. The composites sintered in a mixed Ar/H2/N2 atmosphere exhibited, on average, a lower dry coefficient of friction compared to those sintered in Ar/H2.Publicationtype: Journal Article10 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Controlling the solid-state reaction in Fe-MoS2 self-lubricating composites for optimized tribological properties(Multidisciplinary Digital Publishing Institute (MDPI), 2022-07-06); ; In this work, self-lubricating composites containing MoS₂ and graphite dispersed in an iron matrix were produced by powder metallurgy and sintering. Previous studies demonstrate that MoS₂ reacts with iron matrixes during sintering, making the production of Fe-MoS₂ composites rather difficult. Therefore, this study focused on a potential solution to avoid or reduce this reaction, whilst still providing good tribological properties. Our results show that the addition of graphite retards the reaction of MoS₂ with iron and that the combination of MoS₂ + graphite results in composites with an optimized coefficient of friction associated with a low wear rate both in nitrogen and air atmospheres. Through adequate control of the lubricant’s particle size, composition, and processing parameters, self-lubricating iron-based composites with a low dry coefficient of friction (0.07) and low wear rate (5 x 10⁻⁶ mm³ .N⁻¹.m⁻¹) were achieved.Publicationtype: Journal ArticleScopus© Citations 2 81 373 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Effect of processing route on the microstructure and mechanical properties of hot work tool steel(Universidade Federal de Sao Carlos, 2017-08-21); ; ; ; Powder metallurgy is a growing sector in industrial production, as it offers outstanding energy, cost and material savings in comparison with established processing routes such as casting. Hot work toll steels are usually produced by ingot metallurgy, but also by powder metallurgy, namely hot isostatic pressing and powder forging routes. In this paper we investigate the possibility of production of a hot work tool steel (AISI H13) by conventional (die compaction and pressureless sintering) and metal injection molding routes, aiming to reduce cost and production time. The sintering behavior was studied from 1250 °C until 1430 °C and the resulting parts were compared in terms of microstructure, hardness and tensile strength. The results showed that both shaping routes together with pressureless sintering are suitable to produce this alloy. By combining the best shaping approach and a tailored sintering cycle, it was possible to produce samples with 400 HV10 as well as tensile strength of 1 GPa, which are comparable to the ones obtained by powder forging.Publicationtype: Journal ArticleScopus© Citations 12 279 436 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Effect of hexagonal boron nitride and graphite on mechanical and scuffing resistance of self lubricating iron based composite(Elsevier, 2017-06-15); ; ; ; The production of self-lubricating composites containing second phase particles is one of the most promising choices for controlling friction and wear in energy efficient modern systems. To gain a better understanding of the wear behaviour of such materials, Fe-Si-C matrix composites containing solid lubricants added during the mixing step were studied in this work. The samples were produced using powder metallurgy route, with total contents of 5, 7.5 and 10% in terms of volume of hexagonal boron nitride (hBN) and graphite mixtures as the solid lubricants. The composite's tribological properties were evaluated under reciprocating sliding conditions and their mechanical properties were tested using tensile tests. Additionally, after interruptions at different stages of the reciprocating tests, the wear scars were characterised by Raman spectroscopy and scanning electronic microscopy, to evaluate the evolution of the wear with test time. Higher total solid lubricant contents greatly increased the scuffing resistance of the composites, but decreased the mechanical properties. Furthermore, increasing the hBN content reduced both properties. Among the composites studied, the samples containing 1%vol hBN and 9%vol graphite showed the best combination of mechanical and tribological properties.Publicationtype: Journal Article157