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Fused deposition modelling (FDM) printed short carbon fibre reinforced nylon (SCFRN) composites were fabricated. The friction and wear behaviour of printed materials were systematically investigated under both dry sliding and water lubricated conditions. The results showed that with short fibre enhancements, the printed SCFRN achieved a lower friction coefficient and higher wear resistance than nylon under all tested conditions. Further, under water lubricated conditions, the printed SCFRN exhibited a low, stable friction coefficient due to the cooling and lubricating effects of water. However, the specific wear rate of the printed specimens could be higher than that obtained under dry sliding conditions, especially when the load was relatively low. The square textured surface was designed and created in the printing process to improve materials’ tribological performance. It was found that with the textured surface, the wear resistance of the printed SCFRN was improved under dry sliding conditions, which could be explained by the debris collection or cleaning effect of surface texture. However, such a cleaning effect was less noticeable under lubricated conditions, as the liquid could clean the surface effectively. On the other hand, surface textures could increase the surface area exposed to water, causing surface softening due to the higher water absorption rate. As a result, the samples having surface textures showed higher wear rates under lubricated conditions. The work has provided new insights into designing wear resistant polymer materials using three-dimensional (3D) printing technologies, subjected to different sliding conditions.

Decarburization of steels during heat treatment is a major problem for wear applications and for thin structural components as it often results in poorer surface hardness, strength, and fatigue performance. Additionally, corrosion is a major problem in many engineering applications. To address these issues, this study introduces a novel low-cost surface treatment that utilizes raw materials obtained from automotive waste. This technique was applied on a high-carbon low-alloy martensitic steel that is commonly used in industrial applications for its hardness, strength, and low production cost. The reduction in decarburization led to improved abrasion performance, while the steel’s corrosion resistance was significantly improved through the formation of a thin ceramic layer across the steel’s surface. This treatment, therefore, not only offers a cost-effective solution to decarburization and corrosion, but it also promotes a more sustainable future.

Improvements to the wear performance of CD4MCu (a cast Fe-Cr-Ni-Cu-Mo duplex stainless steel grade) would be of great benefit in pump applications. This study demonstrates that CD4MCu stainless steels reinforced with (Nb0.75,Ti0.25)C particles can be fabricated by simply melting the elements required for the CD4MCu stainless steel together with the amounts of Nb, Ti and C required to achieve a specific volume fraction of (Nb0.75,Ti0.25)C particles in a miniature laboratory argon arc furnace. Their potential as erosion resistant materials was evaluated through microstructural characterization, hardness testing, and sliding wear tests. The formation of (Nb0.75,Ti0.25)C particles was found to improve the bulk hardness of the CD4MCu stainless steels without significantly altering its duplex microstructure, which then led to better wear performance. The results indicate that large-scale casting of the proposed materials should be possible and that they have potential as erosion resistant materials.