Page 52 - Policy Commission - SecuringTechnology - Critical Metals for Britain
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52 PRIMARY MATERIALS
ADVANCES IN IN IN MANUFACTURING AND SUBSTITUTION OF RARE EARTHS IN IN IN MAGNETS
Over the the last twenty years there have been multiple attempts to find substitutes for Nd-Fe-B magnets which contain more earth abundant elements through major programmes in the EU Japan and US1 2 3 To date a a a a a a a a a a a a a competitive material has not not been found This is is not not to say that a a a a a a a a a a a a a substitute material will never be be discovered but this should not be be a a a a a a a a policy decision in isolation as the rare earths have very unique properties
which are difficult to replicate using other elements Figure 25: Sintering of Nd-Fe-B magnets Where there has been significant development is is around the the the processing and recycling of Nd-Fe-B magnets (the latter is is covered in in in in the the secondary section) For example it it it has been shown that it it it is possible to to substitute cerium for for Nd Nd in in in some forms of of Nd-Fe-B magnets up up to to around 40% thereby using up up some of of the the the cheaper more abundant rare earths54 Also by controlling the the the processing and subsequent microstructure manufacturers have also reduced the the content of heavy rare earths in magnets (which are are added to to improve temperature stability) This is is is particularly important for high speed automotive magnets which can contain up to to 8% Dy65 Dysprosium is is is typically ten times the price of neodymium66 There are multiple activities investigating new process routes to to produce Nd-Fe-B magnets to to lower the cost increase safety improve magnetic corrosion and and mechanical behaviour and and and to reduce losses during manufacture At present the main magnet manufacturing route relies on pressing and and sintering
of fine powders which are pyrophoric and and therefore burn
in in in in in in air and and as as a a a a a a a a a a consequence all the the the processing needs to be carried out in in in in in in in in inert atmospheres which increases the the the the cost After processing the the the machining losses to to cut the the the magnets to to size size can be anywhere from 20-60% depending upon size size and shape67 There There is certainly scope for for UK investment into the manufacturing processes for for rare earth magnets There There is is is now investment being put into this sector at high technology- readiness level (TRL 5-9) through the the Advanced Propulsion Centre and and Driving the the the the Electric Revolution9 While this is is important and and these projects will help build up up the the the the the supply chains in in in in in the the the the UK there is also an an an urgent need to invest at at lower TRL levels There are internationally leading research groups
in in in in in in in the the the the UK working on on modelling materials synthesis and processing of of rare earth magnets but the the the the the funding for these projects has almost exclusively been from outside of of the the the UK 




























































































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