Muaj ntau hom hlau nplaum, feem ntau muab faib ua ob pawg: cov hlau nplaum ruaj khov thiab cov hlau nplaum mos.
Cov hlau nplaum tas mus li tau muab faib ua ob pawg:
Thawj qeb yog: hlau nplaum hlau nplaum, suav nrog Neodymium-Iron-Boron hlau nplaum, Samarium Cobalt hlau nplaum, thiab Aluminium-Nickel-Cobalt hlau nplaum.
Qhov thib ob loj qeb yog: Ferrite cov khoom siv hlau nplaum ruaj khov.
(1) Ferrite hlau nplaum: Cov khoom siv tseem ceeb ntawm ferrite suav nrog BaFe12019 thiab SFe12019. Nws muaj ib tug kuj nyuaj kev ntxhib los mos thiab yog ib tug nkig khoom. Vim tias ferrite hlau nplaum muaj qhov kub thiab txias tsis kam, tus nqi qis thiab kev ua haujlwm nruab nrab, nws tau dhau los ua cov hlau nplaum uas siv tau zoo tshaj plaws.
(2) Neodymium-Iron-Boron hlau nplaum (NdFeB): Nws yog cov hlau nplaum uas muaj kev lag luam siab tshaj plaws tam sim no pom. Nws yog lub npe hu ua tus huab tais hlau nplaum. Nws muaj cov khoom sib nqus siab heev thiab nws cov khoom sib nqus siab tshaj plaws (BHmax) yog 10 npaug siab dua li ntawm Ferrite. Kev ua haujlwm machining nws tus kheej kuj zoo heev. Kev ua haujlwm kub tuaj yeem ncav cuag 200 degrees Celsius. Ntxiv mus, nws cov kev ntxhib los mos yog ib qho nyuaj, nws cov kev ua tau zoo yog ruaj khov, thiab nws muaj cov nqi zoo, yog li nws daim ntawv thov yog dav heev. Txawm li cas los xij, vim nws cov tshuaj lom neeg muaj zog, nws qhov chaw yuav tsum tau kho nrog txheej txheej. (xws li Zn, Ni plating, electrophoresis, thiab lwm yam).
(3) Samarium Cobalt hlau nplaum (SmCo) muab faib ua SmCo5 thiab Sm2Co17 raws li lawv cov khoom sib txawv. Nws txoj kev loj hlob yog txwv vim tus nqi siab ntawm cov khoom siv raw. SmCo hlau nplaum tsis tsuas yog muaj cov khoom siv hluav taws xob sib nqus (14-28MGOe), muaj zog coercivity thiab zoo kub yam ntxwv. Piv nrog cov hlau nplaum NdFeB, SmCo hlau nplaum yog qhov tsim nyog rau kev ua haujlwm hauv qhov kub thiab txias.