Magnets and Magnetisers at Cenex LCV 2019

By Paul Fears | 25 July 2019

Grain Boundary Diffused Neodymium Magnets, Magnetisers and Magnet Setters are the focus for Bunting on stand C109 at this year’s Cenex LCV show (4th – 5th September, Millbrook, Bedfordshire, UK).

Cenex-LCV is the UK’s premier low carbon vehicle event.  The show features an extensive seminar programme and the opportunity to ride & drive the latest in-development and commercially available electrified vehicles.  The Bunting stand is in the technology exhibition alongside Aston Martin, Robert Bosch Ltd, and TOYOTA.

Magnets In Electric Vehicles

The motive power in electric vehicles is provided by an electric motor, the mechanics of which are much simpler than that of an internal combustion engine as there is only one moving part.  The rotor can be a number of technologies, but those that incorporate very strong permanent magnets, such as Neodymium Magnets, are overall more efficient than induction machines.  This increased efficiency enables the electric vehicle to provide increased range on the same stored battery energy before being recharged as in the Tesla Model 3

Grain Boundary Diffused Magnets

Using Grain Boundary Diffusion (GBD) technology, Bunting Magnetics offers a range of Neodymium Magnets that are stronger and lower in cost than existing magnet technology.  The temperature of a permanent magnet in a motor could rise above 150 deg C under maximum load conditions, which would cause a magnet with lower intrinsic coercivity to become de-magnetised.  To satisfy the higher temperature requirement, the intrinsic coercivity of magnet is increased by adding the heavy rare earth element Dysprosium.

With added Dysprosium, the magnet will suffer less loss in the same temperature condition, but will be more expensive and have a lower residual magnetic induction or magnetic remanence, otherwise known as Br and BHmax (if the original grade was greater than 35MGOe).

Grain Boundary Diffusion enables a more effective distribution of the heavy rare earth Dysprosium.  The magnetic performance of a standard Neodymium magnet cannot compete as it wastes dysprosium in the grain rather than concentrating it at the grain boundary, therefore less Neodymium Iron Boron (NdFeB) can be utilised per unit volume.

Using less of the heavy rare earth (HRE) mineral Dysprosium makes the magnets considerably more environmentally friendly.  The same amount of rare earth elements (REE) makes five times as many GBD NdFeB Magnets than traditional manufacturing methods.

Magnetising Equipment

Magnetising Equipment is used as a means of post assembly magnetising permanent magnet assemblies such as Halbach Array Surface Mounted Magnet Rotors, IPM motors and Large MRI lugs.

Depending on the volume of magnetic material to be saturated, the application may suit a benchtop system.  Larger magnet volumes require a different design such as the 150kj multi cabinet 5kv system.  Bespoke magnetising fixtures are available and are often required to compliment a customer’s final design.  These can produce high homogeneity bonded Neodymium magnetic fields for applications including rotating field measurement and multipole sensors.

Bunting’s range of magnetisers are used in both industrial and laboratory/research environments.  All designs are PLC controlled, with fixture temperature monitoring and HMI interfaces.

Magnet Setters

Magnet Setters are used in conjunction with a bespoke Magnetising Fixture to accurately charge a magnet and then knock back to a required magnetic field value at a specific point in space with a controlled decaying oscillating magnetic wave.  This provides calibration and accuracy to plus or minus 1 Gauss.

The Magnetic Future

The number of applications for high energy density permanent magnets continues to grow due to increased efficiency and less reliance on other energy sources.  The Bunting Magnet experts look forward to meeting visitors on stand C109 at Cenex LCV to discuss the latest innovations.

Bunting Magnetics produces a wide range of permanent magnets and magnet assemblies.  For further information or to discuss a specific magnet application, please contact us on:

Phone:  +44(0)1442 875081


Via the Bunting Europe website for specialist magnets and magnetic assemblies

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