Kev pab tshwj xeeb ntawm alumina hmoov hauv cov ntaub ntawv sib nqus
Thaum koj rhuav tshem lub tshuab servo ceev lossis lub tshuab tsav muaj zog ntawm lub tsheb fais fab tshiab, koj yuav pom tias cov khoom siv sib nqus precision yeej ib txwm nyob hauv plawv. Thaum cov engineers tab tom tham txog lub zog coercive thiab lub zog sib nqus seem ntawm cov hlau nplaum, ob peb tus neeg yuav pom tias cov hmoov dawb zoo li qub,alumina hmoov(Al₂O₃), tab tom ua lub luag haujlwm ntawm "tus phab ej tom qab qhov xwm txheej". Nws tsis muaj hlau nplaum, tab sis nws tuaj yeem hloov pauv qhov kev ua tau zoo ntawm cov khoom siv hlau nplaum; nws tsis yog conductive, tab sis nws muaj kev cuam tshuam loj heev rau kev hloov pauv ntawm tam sim no. Hauv kev lag luam niaj hnub no uas nrhiav cov khoom siv hlau nplaum zoo tshaj plaws, qhov kev koom tes tshwj xeeb ntawm alumina hmoov tau pom tseeb dua.
Hauv lub nceeg vaj ntawm ferrites, nws yog ib qho "tus kws ua khawv koob ciam teb nplej"
Thaum taug kev mus rau hauv lub chaw ua haujlwm loj loj ntawm cov ferrite mos mos, huab cua puv nrog cov ntxhiab tsw tshwj xeeb ntawm kev kub siab sintering. Old Zhang, tus kws ua tes ua taw ntawm kab ntau lawm, feem ntau hais tias: "Yav dhau los, kev ua manganese-zinc ferrite zoo li cov ncuav mog qab zib steaming. Yog tias qhov kub hnyav dua me ntsis, yuav muaj cov qhov 'siav' sab hauv, thiab qhov poob yuav tsis poob qis." Niaj hnub no, ib qho me me ntawm cov hmoov alumina tau raug qhia rau hauv cov mis, thiab qhov xwm txheej txawv heev.
Lub luag haujlwm tseem ceeb ntawm alumina hmoov ntawm no tuaj yeem hu ua "kev tsim ciam teb ntawm cov noob": nws tau faib sib npaug ntawm cov ciam teb ntawm cov noob ferrite. Xav txog tias ntau cov noob me me tau teeb tsa ze, thiab lawv cov kev sib txuas feem ntau yog cov kev sib txuas tsis muaj zog hauv cov khoom sib nqus thiab "cheeb tsam nyuaj tshaj plaws" ntawm kev poob sib nqus. Cov hmoov alumina purity siab, ultra-fine (feem ntau yog qib submicron) tau muab tso rau hauv cov cheeb tsam ciam teb ntawm cov noob no. Lawv zoo li ntau cov "dams", uas zoo tiv thaiv kev loj hlob ntawm cov noob thaum lub sijhawm kub siab sintering, ua rau cov noob me me thiab faib sib npaug.
Hauv kev sib ntaus sib tua ntawm lub zog magnetism, nws yog "kev ruaj khov ntawm cov qauv"
Tig koj lub siab mus rau lub ntiaj teb ntawm cov hlau nplaum neodymium hlau boron (NdFeB) uas ua haujlwm tau zoo heev. Cov khoom siv no, hu ua "huab tais ntawm cov hlau nplaum", muaj lub zog ceev ceev zoo kawg thiab yog lub hauv paus tseem ceeb rau kev tsav tsheb fais fab niaj hnub, cov turbines cua, thiab cov khoom siv kho mob raug. Txawm li cas los xij, muaj kev cov nyom loj heev nyob tom ntej: NdFeB yooj yim "demagnetization" ntawm qhov kub siab, thiab nws cov theem sab hauv neodymium nplua nuj yog mos thiab tsis muaj kev ruaj khov ntawm cov qauv.
Lub sijhawm no, ib qho me me ntawm cov hmoov alumina tshwm sim dua, ua lub luag haujlwm tseem ceeb ntawm "cov qauv txhim kho". Thaum lub sijhawm sintering ntawm NdFeB, cov hmoov alumina zoo heev raug qhia. Nws tsis nkag mus rau hauv lub lattice theem tseem ceeb hauv ntau qhov ntau, tab sis xaiv tau faib tawm ntawm cov ciam teb ntawm cov noob, tshwj xeeb tshaj yog cov cheeb tsam neodymium-nplua nuj uas tsis muaj zog.
Nyob rau pem hauv ntej ntawm cov hlau nplaum sib xyaw, nws yog "tus neeg sib koom tes ntau yam"
Lub ntiaj teb ntawm cov ntaub ntawv sib nqus tseem tab tom hloov zuj zus. Ib qho qauv sib nqus sib xyaw (xws li Halbach array) uas sib xyaw ua ke qhov siab ntawm qhov sib nqus induction zog thiab qhov poob qis ntawm cov ntaub ntawv sib nqus mos (xws li cov hlau hmoov cores) thiab qhov siab ntawm lub zog coercive ntawm cov ntaub ntawv sib nqus tas mus li tau nyiam mloog. Hauv hom kev tsim kho tshiab no, alumina hmoov tau pom ib theem tshiab.
Thaum nws tsim nyog los sib xyaw cov hmoov sib nqus ntawm cov khoom sib txawv (txawm tias nrog cov hmoov ua haujlwm tsis muaj hlau nplaum) thiab tswj hwm qhov rwb thaiv tsev thiab lub zog kho tshuab ntawm cov khoom kawg, alumina hmoov dhau los ua cov txheej txheem rwb thaiv tsev zoo tagnrho lossis cov khoom siv ntim nrog nws cov rwb thaiv tsev zoo heev, kev tsis muaj tshuaj lom neeg thiab kev sib raug zoo nrog ntau yam khoom siv.
Lub teeb ntawm yav tom ntej: ntau dua thiab ntse dua
Daim ntawv thov ntawmalumina hmoovnyob rau hauv thaj teb ntawmcov ntaub ntawv sib nqustseem tsis tau xaus. Nrog rau kev tshawb fawb tob zuj zus, cov kws tshawb fawb tau cog lus tias yuav tshawb nrhiav kev tswj hwm qhov ntsuas kom meej dua:
Nano-scale thiab kev doping meej: Siv nano-scale alumina hmoov nrog ntau qhov loj sib xws thiab kev sib kis zoo dua, thiab txawm tias tshawb nrhiav nws cov txheej txheem tswj hwm meej ntawm phab ntsa magnetic domain pinning ntawm qhov atomic scale.
Hmoov alumina, cov oxide no los ntawm lub ntiaj teb, nyob rau hauv kev pom kev ntawm tib neeg txoj kev txawj ntse, ua lub khawv koob pom tseeb hauv lub ntiaj teb magnetic tsis pom. Nws tsis tsim lub teb magnetic, tab sis ua rau txoj kev rau kev sib kis ruaj khov thiab ua haujlwm tau zoo ntawm lub teb magnetic; nws tsis tsav lub cuab yeej ncaj qha, tab sis txhaj tshuaj muaj zog dua rau hauv cov khoom siv magnetic tseem ceeb ntawm lub cuab yeej tsav tsheb. Yav tom ntej ntawm kev nrhiav lub zog ntsuab, kev tsav tsheb hluav taws xob zoo thiab kev nkag siab ntse, qhov tshwj xeeb thiab tsis tseem ceeb ntawm alumina hmoov hauv cov khoom siv magnetic yuav txuas ntxiv muab kev txhawb nqa ruaj khov thiab ntsiag to rau kev txhim kho kev tshawb fawb thiab thev naus laus zis. Nws ua rau peb nco qab tias hauv kev sib xyaw ua ke ntawm kev tshawb fawb thiab thev naus laus zis tshiab, cov ntawv yooj yim tshaj plaws feem ntau muaj lub zog tob tshaj plaws - thaum kev tshawb fawb thiab kev ua haujlwm sib ntsib, cov khoom siv niaj hnub kuj yuav ci ntsa iab nrog lub teeb ci ntsa iab.