Synergistic mechanisms of ultrasonic vibration-assisted laser surface texturing on Ti-6Al-4V: microstructural evolution and tribological enhancement

Purpose This study aims to enhance the wear resistance and overall tribological performance of Ti-6Al-4V by proposing an ultrasonic vibration-assisted laser surface texturing (UALST) method. The work elucidates the synergistic mechanism through which ultrasonic vibration influences molten pool dynamics, microstructural evolution and friction-reduction behavior. Design/methodology/approach Numerical simulations incorporating heat transfer, fluid flow and molten pool deformation were performed to predict texture formation under various ultrasonic vibration powers. Experiments were conducted to characterize the morphology, roughness, microhardness, elemental distribution and tribological behavior of UALST-treated surfaces. The simulated texture dimensions were compared with experimental measurements to validate the model. Findings Ultrasonic vibration significantly enhanced molten material flow, increased oxide particle formation and refined the grain structure. As the vibration power increased, surface roughness and microhardness rose markedly, with the maximum microhardness improvement reaching 28.8%. The UALST700 sample exhibited a 78.1% reduction in friction coefficient and the lowest wear volume, attributed to improved debris trapping, strengthened surface layers and the presence of self-lubricating oxide particles. Originality/value This work provides a comprehensive multiscale understanding of the synergistic effects between ultrasonic vibration and laser surface texturing. It establishes a predictive model for texture formation and reveals the mechanisms by which ultrasonic excitation enhances tribological performance. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-11-2025-0529/