The aim will be to quantify the evolution of residual stress (stresses that remain in a material even when under no external stress) and near surface microstructure through the whole duty/life cycle of production and pilot disk work rolls. It will include traditional roll material (cast iron/steel) vs surface engineered roll material as well as new roll materials (Ceramic/Cermet) all provided by the complementary European projects.
The student will exploit the world-leading capabilities including the powerful Diamond Light synchrotron x-ray source and ISIS Neutron Sources for residual stress and leading laboratory x-ray imagers and electron optical microscopes for 3D near surface microstructure mapping. It will also include assessment of the structural integrity of the near surface region of the roll materials using a combination of hardness depth profiling, 3D focused ion beam (FIB) milling, and x-ray tomography of cracks and damage.
The student will evaluate the residual stresses arising initially from manufacturing the rolls before going on to track the evolution of stress and microstructure due to the mechanical-thermal treatment during service including the combined hysteresis of rolling/roll cooling effect/rollshop dressing/machining. Finally they will examine failed rolls to evaluate the influence of residual stress and microstructure on failure. The use of laboratory x-ray will provide much of the data but advanced synchrotron x-ray and neutron diffraction methods will be applied as necessary exploiting the UoM/Diamond light source project. In addition the 3D microstructure will be evaluated by tomography/3D EBSD/electron imaging after FIB micromachining to establish the key length scales for the residual stress and microstructure effects. The student will be in charge of collecting and constructing usable outputs from experiments for effective mapping to FEM models including where possible effects (thermal, mechanical) of microstructural phases of work rolls.
The student will spend time at Tata to link up with Tata modelling capability and twin disk testing providing key starting input data as well as comparing the experimental measurements with the predictions of finite element models of deformation and microstructure as a function of life.
Funding Notes:
Qualifications: Applicants should be educated to at least BEng (Hons) level with a 2:1 or better in Materials, Engineering or Physics and ideally have knowledge of metallurgy, modelling and image analysis.
Funding: A studentship is available for 3 to 3.5 years that covers tuition fees at the Home rate and minimum annual stipend of £13,726 (tax-free).