Diamond-like carbon coatings for electrical steel

Electrical steel is a steel produced in thin strips which can be stacked together to form a magnetic core in electromagnets. Such electromagnets are used in electrical transformers or electric motors, but the electromagnets used in these applications can suffer from electrical losses called “eddy current” and “hysteresis” losses. One effect of these losses is the audable hum produced by transformers. Whereas hysteresis losses arise from turning on and off the electromagnet, eddy losses arise due to the materials used in the electromagnet. Carbon based materials, such as diamond like carbon, can be used to minimise the energy losses due to the eddy currents. For example, even a 1 % improvement in these losses will give a reduction of three to four tonnes of carbon dioxide per tonne of electrical steel over the 25 year transformer lifetime.This project aims to identify a suitable technology for producing conformal diamond-like carbon coatings over large areas on steel substrates. Integration of the diamond-like carbon into electromagnet technology will produce more efficient transformers and electrical motors for green technologies, such as electric vehicles.