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First Feasibility Call:

HiPPES – High performing and processible electrical steels

The performance of electrical machines (e-machines) is affected by many aspects, with the materials being used for the rotor and stator being important in influencing the torque generated and losses during operation. Electrical steels are widely used for e-machines and are based on a binary Fe-Si composition with minor other alloying additions and processed to achieve a non-grain orientated (NGO) microstructure. 

Whilst this material offers good properties and price, development of electrical steels has remained relatively limited with small improvements in performance based on better texture control. However, in recent years further binary based Fe-Si alloys have been produced in the laboratory with a Fe-6.5Si having been shown to offer superior properties particularly for high speed motors. 

This steel is not processable in conventional steel plants due to its low ductility, requiring an expensive vapour deposition/heat treatment process to diffuse Si into the strip. The resultant material is inherently brittle making it more challenging to manufacture into laminations than Fe-3Si steel. Whilst other metal alloys, such as Fe-Co systems, are also available for high speed, high performance e-machines there is a need for improved performance low cost electrical steels.

This project acts to remove the shackles of the binary Fe-Si based approach in electrical steel development, and to show the potential of new alloys that can give a dramatic improvement in core properties, matching, or exceeding, the characteristics of Fe-6.5Si. 

The aim of the work is to carry out a proof of concept approach to developing a new family of electrical steels with improved magnetic / electrical properties whilst being processable using current commercial production routes. The initial approach is to match the magnetic/electrical properties of Fe-6.5 Si steel with significantly enhanced processability, eg high ductility. 

This will be achieved through the following objectives:

The work will involve experts from the Advanced Steel Research Centre (ASRC) and the Electric Machines Research Group (EMRG) from WMG, University of Warwick.

Members of the team on the Davis feasibility call, with their names and roles listed.
Members of the Davis project: Professor Claire Davis, Head of the ASRC (left), Dr Carl Slater, Senior Research Fellow in the ASRC (middle) and Dr Juliette Soulard, Associate Professor EMRG (right).
Left: Vacuum induction melting for production of larger steel ingots. Right: Casting of smaller steel ingots.
Figure 1: Vacuum induction melting for production of bespoke steel compositions of 4.5-7kg ingot size (left) and casting of small (approximately 1kg) ingots in air (right).