Enhanced durability of MoS2-coated C28000 brass achieved via combined laser-induced texture patterns with various morphologies

Cu–Zn (C28000) brass is widely used in friction-intensive applications but has low wear resistance, often requiring continuous lubrication. Molybdenum disulphide (MoS₂) is an effective solid lubricant; however, its performance declines over time due to depletion. Laser surface texturing (LST) can extend lubricant retention, with texture characteristics being critical. While individual parameters such as texture size and orientation have been studied, the combined effect of texture shape, hybrid pattern configurations, and texture density (TD) on lubricant replenishment intervals remains underexplored. This work systematically investigates single-shape and combined-shape texture patterns with varying TD on C28000 brass under MoS₂ lubrication. Patterns were produced using a fibre infrared nanosecond pulsed laser and tested via ball-on-disc experiments. Samples were examined using optical profilometry, scanning electron microscopy, and energy-dispersive spectroscopy. Increasing TD from 5% to 75% extended the MoS 2 retention period by at least 65% for all texture designs. Less common morphologies, such as concentric rings and dimple–grid patterns, were also examined and further assessed using finite element simulations. Concentric ring textures at the highest TD achieved the longest retention (28 times longer compared to non-TD samples) due to their closed-loop geometry, which promoted lubricant entrapment and delayed depletion. Grid textures showed the shortest retention because open channels facilitated rapid lubricant escape. Hybrid patterns offered no benefit and sometimes reduced performance by disrupting reservoir continuity. These results quantify how texture geometry and TD influence lubricant depletion through changes in reservoir continuity and escape pathways, providing design guidelines for extending service intervals of solid-lubricated brass components.