10144661In-situ capability assessment for rail repair via additive manufacturingClosedSmall Business Research InitiativeInnovate UKRailway track components, particularly those made from conventional rail steel, face a limited lifespan due to the high compressive and shear loads they experience on a small contact area between the rail and the wheel, which involves both rolling and sliding contact. The UK's high maintenance costs and lengthy possession times, necessitated by the removal and replacement of damaged rail sections, underscore the urgent need for innovative solutions. As new rail steel grades are introduced, it becomes imperative to develop corresponding maintenance techniques. This project aims to advance a rapid, in-situ rail repair or enhancement method that can be executed within 10 minutes, significantly reducing both costs and downtime. By leveraging proven workshop technology and methods for laser-clad coatings on standard-grade rail, we will focus on developing a technique capable of repairing rail and track components using like-on-like materials in-situ, catering to both standard and premium-grade rails. The main advantage of using a laser based cladding system is the inherent low heat input of the process. When compared to conventional cladding/welding processes, a laser-based system produces a very small heat affected zone (HAZ) and produces minimal changes to the mechanical properties of the substrate rail material. It also gives a geometrically precise and reproducible weld with good microstructure and no defects (such as porosity) and produces a significantly better surface finish, reducing the need for final machining or dressing to blend into the original rail surface. This project will involve repairing one-metre lengths of standard and premium-grade rail using a like-on-like clad repair material. The clad material will be produced from rail steel by atomising it into powder for application using a one-step laser cladding technique. Before cladding, appropriate pre-heating will be applied to ensure optimal bonding. The laser-clad coating repair will be performed in a controlled environment free from contaminants. Testing of the repairs will then be conducted in the full-scale test wheel/rail test facility (FSR). This facility, originally built by British Rail and used in previous research at The University of Sheffield, simulates real-world conditions by subjecting the repaired rail to the dynamic loads of a moving wheel and rail. The repaired rail sections will be observed for performance, then removed for detailed analysis. The developed method aims to be adaptable for in-situ application, thereby eliminating the need for rail removal and minimising disruptions to train services.