Electrical Steels: Magnetic properties enhancement using alternative manufacturing processes

Academic Institution: University of Strathclyde

Academic Supervisor: Professor Paul Blackwell

Industry Partner: Tata Steels / Cogent Power Ltd

PhD Student: TBC

Start Date: TBC

Abstract

Tata-Steel spans across 5 continents and is recognised as one of the largest manufacturers and suppliers of steel products. Cogent-Power, as a part of Tata-Steel business, focuses on electrical steels and its manufacturing processes.

This PhD proposal is a collaboration between Cogent-Power and AFRC on the development and advancement of electric steel (E-steel) technologies for electrical vehicles.

Historically, Scotland was one of the world’s greatest steel producing nations. Scotland is also one of the world leaders in renewable power production. By building on these two capabilities and merging them, Scotland can take a significant step forward in leading E-steel technology and the advantages that are presented in this ever more technology focused world.

As technology has advanced, demand for electrical vehicles has grown significantly. This is in part due to strict emission policies and increased fuel prices as well as favourable stance from the government on electrification of vehicles. Therefore, there are strong drivers for working towards developing enhanced electrical motors to provide increased efficiency in electrical vehicles. Perusing this avenue of research in a rapidly growing technology field will create more opportunities for Scottish companies and research centres.

The winding core of electric motors is manufactured from a laminate of E-steel. This E-steel component is key in transforming electrical energy to mechanical torque. From a metallurgical-point-of-view, the microstructure/texture of the E-steel laminate, which controls the magnetic properties, has a great impact on the energy efficiency of the motors. The fundamental objective of the proposed PhD application is to investigate the effect of thermomechanical processing and annealing parameters on the final microstructure/texture of the manufactured part and consequently, on their magnetic properties. This proposal will target the final stages of cold/warm forming and annealing. To that end, a newly designed/manufactured testing rig for repetitive-bending-under-tension (R-BUT) and asymmetric-rolling will be used to apply plastic deformation in the E-steel sheets featuring a large shear strain to control their microstructure/texture. The recrystallization annealing of the deformed sheets will be studied using in-situ texture analysis during annealing by neutron-diffraction and the SEM/EBSD technique. In this work, two grades of low-Si (0.9%Si) and ultrahigh-Si E-steel (6.5%Si) will be considered. This proposal also addresses the industrial challenge of forming the 6.5%Si E-steel due to its poor mechanical properties. Furthermore, the effect of cut edge during stamping on the magnetic properties of the E-steel sheets will be investigated.

This work will take place at the AFRC; it facilitates an effective engagement between AFRC and Cogent-Power and will establish new strong collaboration with the TUDelft (the Netherlands), Canmet (Canada) and Universite Paris-13 (France).


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