With increasingly stringent greenhouse gas exhaust emission legislation, alternative powertrains from the conventional Internal Combustion Engine (ICE) have gained much interest in recent years. Two leading alternative powertrains are fully-electric and ICE-electric hybrid. The rise of these alternative powertrain technologies has been fuelled greatly by motorsport, with ICE-electric hybrid powertrains established in Formula 1 from 2009, while Formula E, contested by fully-electric powertrains, was established in 2014. Moreover, these alternative powertrain technologies developed at the pinnacle of motorsport have filtered down to the production passenger car, with numerous automotive Original Equipment Manufacturers (OEMs) offering ICE-electric hybrid and even fully-electric powered vehicles. The core of the electric Motor Generator Unit (MGU) is manufactured from strip Non-Grain Orientated (NGO) Electrical Steel. Hot rolled strip NGO Electrical Steels are manufactured by Tata Steel Europe at the Port Talbot site. Subsidiary of Tata Steel Europe, Cogent Power, then completes strip steel processing, with hot-band annealing, cold rolling to gauges down to 0.1 mm, final annealing, coating, cutting to size, stamping to part geometry and stacking to produce the final laminates for application to the MGU. Magnetic properties and mechanical properties are both of utmost importance to Electrical Steels for MGU applications. Electrical efficiency of the MGU depends on magnetic properties of the strip steel, with high magnetic flux important for maximum torque at low speeds and low eddy current losses important for maximum power at high speeds. Meanwhile, rotational stresses within the MGU demand that the strip steel exhibits sufficient mechanical strength, where such rotational stresses increase as higher power output is demanded, with the MGU operating at up to 16,000 rpm. This creates a challenge given that all fundamental microstructural strengthening mechanism, including solid solution strengthening, precipitation strengthening, grain boundary strengthening and secondary phase strengthening, are detrimental to magnetic properties, increasing eddy current losses and decreasing power output from the MGU.
The objective of the research project will be to develop NGO Electrical Steels for automotive MGU applications. This will focus on optimising hot rolling parameters and resulting hot-band microstructural characteristics for optimal microstructural evolution during down-stream strip processing and in turn, for optimal magnetic and mechanical properties in the MGU. Hot rolling parameters will include hot rolling stress-strain states, hot rolling strains, hot rolling strain rates, hot rolling temperatures, hot-band gauge, finishing temperature, run-out-table cooling path and coiling temperature. Characterising and correlating microstructural distributions to final magnetic and mechanical properties will be of high interest, where microstructural evolution is known to be different through hot-band gauge, with different local stress-strain states and temperatures resulting in different grain sizes, grain orientations and defect densities between strip surface and strip centre. The project will contribute directly to New Product Development activities at Tata Steel Europe, providing the customer of Tata Steel Europe with high-value added products. The project will involve laboratory hot rolling simulations where a wide range of process variables will be investigated, followed by standardised laboratory down-stream strip processing simulations and then microstructural, magnetic and mechanical property characterisation of the final strip product. State-of-the-art research facilities will be utilised, including anisothermal hot tensile / compression testing, laboratory hot mill, 3-dimensional Electron Back-Scattered Diffraction (EBSD) and X-Ray Diffraction (XRD). The ultimate target is full-scale industrial trials from steelmaking through to performance testing of the MGU.
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Sponsoring Company Tata Steel
Candidates should hold an Engineering or Physical Sciences degree with a minimum classification level of 2:1 or equivalent relevant experience. This project would be suitable for someone with a degree in Metallurgical Engineering. Genuine interest in Physical Metallurgy. Knowledge of mechanical testing techniques, stress-strain behaviour, magnetic properties, heat treatment, microstructural analysis techniques and microstructure-mechanical-magnetic property relationships. Ability to communicate and network with different stakeholders from academia and industry; and from Technicians to Senior Management.
Our funders require applicants to also meet the following eligibility criteria:
Further information regarding eligibility criteria can be found at: http://www.materials-academy.co.uk/eligibilityFunding
The studentship covers the full cost of UK/EU tuition fees, plus a tax free stipend of £20,000 p.a.Closing Date 21 July 2017