Tribological Behavior of Ti-6Al-4V Alloys Processed by Selective Laser Melting and Conventional Casting Process

This work presents a detailed assessment of the microstructural features and tribological behaviour of Ti6Al4V alloy produced by conventional casting followed by rolling (CR) and selective laser melting (SLM). The two fabrication routes yield markedly different microstructures: the CR alloy develops a dualphase α + β microstructure, whereas the SLM alloy forms a fine martensitic α′ lath morphology with enhanced hardness. Tribological experiments performed under various loads and sliding speeds reveal clear distinctions in frictional response and wear characteristics. The CR samples exhibit deeper ploughing grooves, stronger oxidation effects, and higher coefficients of friction, indicating that abrasive and oxidationassisted wear dominate their surface degradation. In contrast, the SLM samples show shallower wear tracks, reduced friction, and improved resistance to material removal, with delamination and adhesive wear occurring only under more severe test conditions. The lower COF and diminished wear severity observed in the SLM alloy highlight the advantages of its refined microstructure in stabilizing interfacial contact and reducing frictional energy losses. Overall, the results confirm the superior tribological performance of SLMprocessed Ti6Al4V for applications demanding high wear resistance and structural reliability.