Optimization of micro-dimpled textures on sliding-rolling contact surfaces under starved lubrication and heavy load conditions

Purpose Gears operating under starved lubrication and heavy loads often suffer from elevated friction and accelerated wear, leading to performance degradation or failure. This study aims to investigate the influence of micro-dimpled texture parameters on the tribological behavior of line contact sliding-rolling surfaces under such extreme conditions, aiming to optimize texture design. Design/methodology/approach Sliding-rolling tests using cylindrical specimens were conducted to simulate gear meshing under starved lubrication and heavy loads. A quadratic rotation orthogonal combination test assessed the effects of dimple diameter, depth and spacing on the average friction coefficient and surface wear (quantified by roughness change, ΔRz). Regression models were established using response surface methodology (RSM), followed by multi-objective optimization. Findings The experimental results show an optimal proportional relationship between the texture parameters, which made the tribological performance of the tested samples the best. Using the main objective function method, the texture parameters were optimized, yielding a preferred combination of 67 µm in diameter, 54 µm in depth and 654 µm in spacing. Compared to non-textured surfaces, this optimized configuration reduced the average friction coefficient by 33.3% and the ΔRz value by 42.3%. Originality/value This study experimentally evaluates and optimizes micro-dimpled textures for gear-like surfaces under extreme conditions, offering theoretical and practical guidance for enhancing tribological performance in oil-starved, high-load environments. Peer review The peer review history for this article is available at: Link to the website of publons.