MANUFACTURING EFFECTS IN ELECTRICAL STEELS FOR AUTOMOTIVE DRIVES

Electrical steels are the active material in all electric motors and generators and their properties are crucial to the performance and efficiency of these devices. As such they are critical materials for the delivery of the electrification of the transport sector and renewable energy generation. The processing of these materials is highly complex but continues to develop at an accelerating rate due to the primary drivers discussed. The properties of these materials are highly non-linear and sensitive to a wide range of processing, manufacturing and operational parameters such that the performance of completed device is difficult to predict. The most challenging of these is to understand the influence of the manufacturing process on the magnetic properties of the electrical steel laminations. The process consists of cutting, stamping, joining, winding and shrink fitting all of which introduce mechanical damage and/or stress into the material.

Cardiff University has previously pioneered a local magnetic measurement technique whose viability for the assessment of cut edges was proven in a recent collaboration with Cogent Power. It is proposed to refine this technique and apply it to a range of current and experimental electrical steels subject to simulated and real manufacturing processes in order to fully characterise their response. This will be used to develop a physical model of the mechanical processes and couple this to the magnetic properties such that computer simulations may be created allowing the optimisation of both the materials and the manufacturing process. In parallel to this a computationally efficient engineering model will be developed for incorporation into finite element design packages such that machine designers can take these important effects into account during the design process.

The project will also build on work conducted within the schools of Chemistry and Engineering at Cardiff University (again in collaboration with Cogent Power) to develop enhanced and new coating technologies. Coatings developed and proposed by this work will be investigated for their performance through the manufacturing process and their possible role in mitigating some of the effects of processing. Functional coatings offering additional performance through bonding, high strength or tool lubrication will be thoroughly investigated.