The classification of the permanent magnets

　　Permanent magnets, according to its composition, can be divided into iron, cobalt, manganese and iron oxy. Iron-based permanent magnets make iron as the main component, other components are AI, Ni, Cu, Mo, W, Cr, C etc.. Cobalt-based permanent magnets make cobalt as main component, other components have rare earth cobalt ( R-Co ), Pt, Cu, Fe, Pd, Mn, Cr etc.. Manganese-based permanent magnets make manganese as main component, other components have Ag, C, AI.Bi, Au etc; components of permanent magnetic ferrite have CoFe204, BaO •6Fe2O3• BaMe2 •Fe6O27, ( Me has two valence ions ), SrO, 6Fe2O3 etc..

　　The ( BH ) m of rare earth permanent magnet is the highest, which has nearly 320000 kJ / M 3, the coercivity reaches 4458000 / m, and is a series of intermetallic compounds, composed of a rare earth element and iron element, but the price is high. Ductile permanent magnet with A good processing performance has iron - chromium - cobalt alloy, iron and cobalt, manganese, vanadium alloy silver aluminum alloy, not only can be heat processing, can also be cold processing, magnetic and good mechanical properties, turning, cutting, drilling, wire can be processed into a plate and so on.