Materials and Surface Engineering, Transportation

Rolling stock wheels are a key component of the performance and life of both infrastructure and rolling stock, a cost driver of the rail industry and critical for safe operation of the railway. Current wheel repair processes based on cutting and replacement are time consuming and wasteful. Additive manufacturing has been recognised as a major disruptive technology that has the potential to make extraordinary changes in many areas. This project aims to develop novel technologies based on high resolution laser manufacturing methods that can successfully repair wheel flats and wear. The materials and tribology research groups at Southampton have developed expertise in high resolution laser printing and rolling contact testing that would ensure the success of this project.

The key objectives addressed in the proposed work are to:

• Fully understand wheel-rail contacts including material performance requirements, microstructure evolution with representative heat treatments, standard wheel material tests, materials performance under the service operation conditions, wheel repair processes and cost issues;
• Develop a high resolution laser cladding processes using micro dry powder dispensing technology to rework the wheel profile and surface;
• Assess the production and subsequent service evolution of these additive layers using advanced characterisation and imaging techniques including SEM, TEM, XRD, EDX, EBSD and X-ray CT to evaluate the microstructures produced, their adhesion properties, residual stresses, relevant in-service mechanical properties and structural integrity compared to the base material;
• Test the repaired surfaces under the service conditions on a two-roller machine to evaluate their tribological performance, including lubrication, friction, wear and life, of the ‘repaired’ surfaces.

If you wish to discuss any details of the project informally, please contact Dr Ling Wang, national Centre for Advanced Tribology at Southampton (nCATS), Email: ling.wang<στο>soton.ac.uk, Tel: +44 (0) 2380 59 3016.