Research and status on laser additive remanufacturing of critical components for rail vehicles

Railway transportation is the lifeline of the national economy, developing towards higher speed, heavier loads, and more complex application environments. The performance and service safety of its critical load-bearing components (such as wheels, axles, brake discs, and other rotating parts) are of paramount importance. These components consistently face prevalent problems including wear, fatigue, and damage-induced failure. Conventional repair methods often suffer from drawbacks such as excessive heat input, significant distortion, and weak bonding interfaces. In contrast, laser additive remanufacturing technology offers notable advantages, including high interfacial bonding strength, controllable dilution rates and heat-affected zones, and minimal thermal distortion. It provides a promising solution for high-quality repair and remanufacturing of metal components. In this study, we review the primary failure modes of key load-bearing parts in railway vehicles, then outline the technical principles and classifications of laser additive remanufacturing, after that summarize recent domestic and international research advances in material development, process monitoring, parameter optimization, and fundamental performance evaluation. Furthermore, this paper discusses current technical challenges and identifies future development opportunities to promote the sustainable growth of the rail transit remanufacturing industry.