The rate of growth in the production of RE-Magnets has continued unabated, despite fluctuations in the world economy. Thus, sintered NdFeB magnets are exhibiting a current growth rate of ~12% whereas the growth rate for bonded NdFeB magnets is in excess of 20%.
The total value of hard magnets now exceeds that of soft magnets and the gap is widening. The reason for this spectacular growth has been due partially to the booming global PC market, as around 60% of NdFeB magnet production goes into disc-drive applications, primarily voice-coil-motors (VCMs).
This is by no means the whole story however and a summary of the very wide range of applications for RE-magnets is given below, with many of these being capable of substantial further growth.
In general terms, permanent magnets are far more important than is generally realised and this is perhaps, best illustrated by their use in the motor car. In the early fifties a car would have one magnet (the speedometer) whereas some modern cars can have over a hundred permanent magnet motors.
Currently these are almost exclusively based on Sr-ferrite (SrFe12019) and the penetration of NdFeB magnets into this area requires a significant cost reduction, an increase in the maximum operating temperature and improvement in corrosion resistance.
The potential benefits of using NdFeB magnets would be a significant reduction in volume and weight and an improved efficiency. This will probably be a major influence in the use of these magnets in the future.
Growing concern about global warming has scientific and technological implications and many of these impinge on the use of NdFeB magnets. Future uses could include their more widespread use in “white goods” such as washing machines, refrigerators etc, in order to improve energy efficiency and hence reduce CO2 emissions.
Another large use could be in generators for domestic combined heat and power units and in clean energy production such as windmills. The biggest potential however is in electric vehicles (EVs) which could be hybrid vehicles or totally driven by electricity in the form of batteries or a fuel cell.
There has been an enormous increase of interest and activity in this area over the past 5 years and the Japanese have been the first to commercialise these vehicles.
Examples of applications for permanent magnetic materials:
Starter motors, Anti-lock braking systems (ABS), Motor drives for wipers, Injection pumps, Fans and controls for windows, seats etc, Loudspeakers, Eddy current brakes, Alternators.
Loudspeakers, Microphones, Telephone ringers, Electro-acoustic pick-ups, Switches and relays.
Disc drives and actuators, Stepping motors, Printers.
DC motors for showers, Washing machines, Drills, Low voltage DC drives for cordless appliances, Loudspeakers for TV and Audio, TV beam correction and focusing device, Compact-disc drives, Home computers, Video Recorders, Clocks.
Electronic and Instrumentation:
Sensors, Contactless switches, NMR spectrometer, Energy meter disc, Electro-mechanical transducers, Crossed field tubes, Flux-transfer trip device, Dampers.
DC motors for magnetic tools, Robotics, Magnetic separators for extracting metals and ores, Magnetic bearings, Servo-motor drives, Lifting apparatus, Brakes and clutches, Meters and measuring equipment.
Astro and Aerospace:
Frictionless bearings, Stepping motors, Couplings, Instrumentation, Travelling wave tubes, Auto-compass.
Dentures, Orthodontics, Orthopaedics, Wound closures, Stomach seals, Repulsion collars, Ferromagnetic probes, Cancer cell separators, Magnetomotive artificial hearts, NMR / MRI body scanner.