Yikuphi ukusebenza kazibuthe okufakwe ezintweni ezihlala njalo?
Ukusebenza okuyinhloko kazibuthe kufaka phakathi i-remanence(Br), i-magnetic induction coercivity(bHc), i-intrinsic coercivity(jHc), kanye nomkhiqizo wamandla omkhulu (BH)Max.Ngaphandle kwalezo, kukhona okunye ukusebenza okuningana: I-Curie Temperature(Tc), I-Working Temperature(Tw), i-coefficient yezinga lokushisa ye-remanence(α), i-coefficient yezinga lokushisa ye-intrinsic coercivity(β), ukubuyiselwa kokungena kwe-rec(μrec) kanye nejika likanxande demagnetization (Hk/jHc).
Ayini amandla kazibuthe?
Ngonyaka we-1820, usosayensi u-HCOersted eDenmark wathola ukuthi inaliti eduze kocingo olune-deflect yamanje, eveza ubuhlobo obuyisisekelo phakathi kukagesi kanye ne-magnetism, ke, i-Electromagnetics yazalwa.Ukuzijwayeza kubonisa ukuthi amandla kazibuthe kanye namanje namanje intambo engapheli ekhiqizwe nxazonke ilingana nosayizi, futhi ilinganisa ngokuphambene nebanga ukusuka ocingweni.Kusistimu yeyunithi ye-SI, incazelo yokuthwala ama-ampere angu-1 wentambo engapheli yamanje ebangeni elingu-1/ ucingo (2 pi) ibanga lamamitha wamandla kazibuthe ngu-1A/m (an / M);ukukhumbula umnikelo ka-Oersted ku-electromagnetism, kuyunithi yohlelo lwe-CGS, incazelo yokuthwala ama-ampere angu-1 womqhubi wamanje ongenamkhawulo kumandla kazibuthe webanga elingu-0.2 lentambo ibanga lingu-1Oe cm (Oster), 1/ (1Oe = 4 PI) * 103A/m, namandla kazibuthe ngokuvamile avezwa ngo-H.
Iyini i-polarization kazibuthe (J), uyini amandla kazibuthe (M), uyini umehluko phakathi kwakho kokubili?
Ucwaningo lwesimanje luzibuthe lukhombisa ukuthi zonke izenzakalo kazibuthe zisuka kweyamanje, ebizwa ngokuthi i-dipole kazibuthe.Itorque enkulukazi kazibuthe endaweni engenalutho yimzuzu kazibuthe we-Pm ngeyunithi yendawo kazibuthe yangaphandle, kanye nomzuzu we-dipole uzibuthe ngeyunithi ngayinye yevolumu. impahla ingu-J, kanti iyunithi ye-SI ithi T (Tesla).Ivekhtha yesikhathi sikazibuthe ngeyunithi ngayinye yevolumu yento engu-M, futhi umzuzu kazibuthe ngu-Pm/ μ0, kanti iyunithi ye-SI ingu-A/m (M / m).Ngakho-ke, ubudlelwano phakathi kuka-M no-J: J =μ0M, μ0 okokuvumela ukungena kwe-vacuum, kuyunithi ye-SI, μ0 = 4π * 10-7H/m (H / m).
Iyini i-magnetic induction intensity (B), iyini i-magnetic flux density (B), buyini ubudlelwano phakathi kuka-B no-H, J, M?
Uma inkambu kazibuthe isetshenziswa kunoma iyiphi i-H ephakathi, amandla kazibuthe phakathi nendawo awalingani no-H, kodwa amandla kazibuthe ka-H kanye ne-magnetic medium J. Ngoba amandla kazibuthe ngaphakathi kwento ebonakalayo aboniswa nguzibuthe inkambu H ngokusebenzisa i-medium yokungeniswa.Ukuze sihluke ngo-H, sikubiza ngokuthi i-magnetic induction medium, echazwa ngokuthi B: B= μ0H+J (iyunithi ye-SI) B=H+4πM (amayunithi e-CGS)
Iyunithi yamandla kazibuthe wokungeniswa ngu-B ngu-T, kanti iyunithi ye-CGS i-Gs (1T=10Gs).Isenzakalo sikazibuthe singamelwa ngokusobala imigqa yensimu kazibuthe, futhi ukungenisa kazibuthe B kungachazwa nangokuthi ukuminyana kazibuthe.I-Magnetic induction B kanye ne-magnetic flux density B ingasetshenziswa emhlabeni wonke emcabangweni.
Yini ebizwa nge-remanence (Br), lokho okubizwa ngokuthi amandla kazibuthe aphoqayo (bHc), yini amandla angaphakathi okuphoqeleka (jHc)?
Imagnetization yamagnetic field to saturation ngemva kokuhoxiswa kwenkundla kazibuthe yangaphandle esimweni esivaliwe, i-magnet magnetic polarization J kanye ne-induction yangaphakathi kazibuthe B futhi ngeke zinyamalale ngenxa yokunyamalala kwe-H kanye nenkundla kazibuthe yangaphandle, futhi izogcina inani elithile likasayizi.Leli nani libizwa ngokuthi uzibuthe wokungeniswa uzibuthe osalayo, okubizwa ngokuthi i-remanence Br, iyunithi ye-SI ingu-T, iyunithi ye-CGS i-Gs (1T=10⁴Gs).Ijika likakazibuthe likazibuthe unomphela, lapho inkambu kazibuthe ehlehlayo ikhuphuka ibe yinani le-bHc, ukuqina kazibuthe kazibuthe ongu-0 kwakungu-0, okubizwa ngokuthi inani lika-H lezinto eziphambene kazibuthe zokuphoqeka kazibuthe kwe-bHc;endaweni kazibuthe ehlehlayo H = bHc, ayibonisi amandla kazibuthe angaphandle, ukucindezelwa kokubonakaliswa kwe-bHc kwezinto ezibonakalayo ezinozibuthe ezihlala njalo ukumelana nesizinda samagnetic sangaphandle noma omunye umphumela wokuqeda uzibuthe.I-Coercivity bHc ingenye yemingcele ebalulekile yomklamo wesekethe kazibuthe.Lapho i-reverse magnetic field H = bHc, nakuba uzibuthe engabonisi ukugeleza kazibuthe, kodwa amandla kazibuthe kazibuthe J ahlala eyinani elikhulu ekuqondeni kwangempela.Ngakho-ke, izici zamagnetic zangaphakathi ze-bHc azanele ukuveza umazibuthe.Lapho inkambu kazibuthe ehlehlayo ikhuphuka ibe yi-jHc, i-vector micromagnetic dipole magnet yangaphakathi ingu-0. Inani lendawo kazibuthe elihlehlayo libizwa ngokuthi ukuphoqelelwa kwangaphakathi kwe-jHc.I-Coercivity jHc iyipharamitha ebonakalayo ebaluleke kakhulu yezinto ezibonakalayo zikazibuthe, futhi iwukubonakaliswa kwezinto ezinozibuthe ezihlala njalo ukumelana nesizinda sikazibuthe esibuyela emuva noma omunye umphumela wokuqeda uzibuthe, ukuze kugcinwe inkomba ebalulekile yekhono layo lokuqala lokuzibuthe.
Uyini umkhiqizo wamandla omningi (BH) m?
Ejikeni le-BH lokukhipha uzibuthe wezinto ezisebenza kazibuthe ezihlala unomphela (ku-quadrant yesibili), amaphoyinti ahlukene omazibuthe asesimweni esihlukile sokusebenza.Ijika le-BH demagnetization lephoyinti elithile ku-Bm ne-Hm (izixhumanisi ezivundlile nezime mpo) limele ubukhulu bukazibuthe kanye namandla okungenisa kazibuthe kanye nenkundla kazibuthe yezwe.Ikhono le-BM ne-HM yenani eliphelele lomkhiqizo i-Bm*Hm limelela isimo somsebenzi wangaphandle kazibuthe, olingana namandla kazibuthe agcinwe kuzibuthe, okuthiwa i-BHmax.Uzibuthe osesimweni senani eliphezulu (BmHm) umele ikhono lomsebenzi ozibuthe wangaphandle, elibizwa ngokuthi umkhiqizo wamandla omkhulu kazibuthe, noma umkhiqizo wamandla, ochazwa ngokuthi (BH) m.Iyunithi ye-BHmax ohlelweni lwe-SI ngu-J/m3 (ama-joules / m3), kanye nohlelo lwe-CGS lwe-MGOe , 1MGOe = 10²/4π kJ/m3.
Liyini izinga lokushisa le-Curie (Tc), liyini izinga lokushisa likakazibuthe (Tw), ubudlelwano phakathi kwabo?
Izinga lokushisa le-Curie izinga lokushisa lapho i-magnetization yezinto zikazibuthe iyancipha ibe ziro, futhi iyiphuzu elibalulekile lokuguqulwa kwezinto ezisetshenziswayo ze-ferromagnetic noma ze-ferrimagnetic zibe izinto ze-para-magnetic.Izinga lokushisa le-Curie Tc lihlobene kuphela nokwakheka kwezinto futhi alihlobene nesakhiwo esincane sempahla.Ezingeni elithile lokushisa, izici kazibuthe zezinto ezinozibuthe ezihlala njalo zingancishiswa ngebanga elithile uma kuqhathaniswa nalelo lasekamelweni.Izinga lokushisa libizwa ngokuthi izinga lokushisa elisebenzayo likazibuthe Tw.Ubukhulu bokunciphisa amandla kazibuthe buncike ekusetshenzisweni kukazibuthe, kuyinani elinganqunyiwe, uzibuthe ofanayo unomphela ezinhlelweni ezahlukene zinezinga lokushisa elihlukile le-Tw.Izinga lokushisa le-Curie le-Tc magnetic material limele ithiyori yomkhawulo wokushisa osebenzayo wento.Kuyaphawuleka ukuthi i-Tw esebenzayo yanoma yimuphi uzibuthe unomphela ayihlobene kuphela ne-Tc, kodwa futhi ihlobene nezakhiwo kazibuthe zikazibuthe, njenge-jHc, kanye nesimo sokusebenza sikazibuthe kumjikelezo kazibuthe.
Kuyini ukungena kazibuthe kukazibuthe unomphela (μrec), liyini ijika lejika le-J demagnetization (Hk / jHc), abakushoyo?
Incazelo yejika lokuyeka uzibuthe lephoyinti lokusebenza uzibuthe le-BH eliphindaphindayo umugqa wethrekhi obuyela emuva ozibuthe oguquguqukayo, umthambeka womugqa wokubuyisela ukufinyeleleka okungu-μrec.Ngokusobala, i-permeability yokubuyisela i-μrec ibonisa ukuzinza kukazibuthe ngaphansi kwezimo zokusebenza ezinamandla.Iyisikwele sejiko likakazibuthe elihlala unomphela i-BH demagnetization, futhi ingenye yezinto ezibalulekile kazibuthe zozibuthe baphakade.Kozibuthe be-Sintered Nd-Fe-B, μrec = 1.02-1.10, i-μrec encane, kungcono ukuzinza kukazibuthe ngaphansi kwezimo zokusebenza eziguquguqukayo.
Iyini isekethe kazibuthe, iyini isekethe kazibuthe evulekile, isimo esivaliwe?
Isifunda kazibuthe sibhekiselwa endaweni ethile esikhaleni somoya, esihlanganiswe yilowo noma ubuningi bamagnetic unomphela, ucingo oluthwalayo lwamanje, insimbi ngokusho komumo nosayizi othile.I-ayoni ingaba yi-iron emsulwa, insimbi ye-carbon ephansi, i-Ni-Fe, i-Ni-Co alloy enezinto eziphezulu zokungena.Insimbi ethambile, eyaziwa nangokuthi ijoka, idlala ukugeleza kokulawula ukugeleza, ikhuphule amandla kazibuthe wendawo, ivimbele noma inciphise ukuvuza kazibuthe, futhi ikhulise amandla emishini yezingxenye zendima kumjikelezo kazibuthe.Isimo sikazibuthe sikazibuthe oyedwa ngokuvamile sibizwa ngokuthi isimo esivulekile lapho insimbi ethambile ingekho;lapho uzibuthe usesiyingi se-flux esakhiwe ngensimbi ethambile, umazibuthe kuthiwa usesimeni sesifunda esivaliwe.
Yiziphi izici zemishini zomazibuthe be-Nd-Fe-B abasikiwe?
Izakhiwo zemishini yezibuthe ze-Sintered Nd-Fe-B:
| Ukugoba Amandla/MPa | Amandla Wokucindezela /MPa | Ukuqina /Hv | I-Yong Modulus /kN/mm2 | Ubude/% |
| 250-450 | 1000-1200 | 600-620 | 150-160 | 0 |
Kuyabonakala ukuthi umazibuthe we-Nd-Fe-B owenziwe nge-sintered uyinto ejwayelekile ephukayo.Ngesikhathi senqubo yomshini, ukuhlanganisa nokusebenzisa odonsa, kuyadingeka ukunaka ukuvimbela uzibuthe ekubeni nomthelela onzima, ukushayisana, kanye nokucindezeleka okukhulu okuqinile, ukuze ugweme ukuqhekeka noma ukuwa kukazibuthe.Kuyaphawuleka ukuthi amandla kazibuthe we-sintered Nd-Fe-B magnetics anamandla kakhulu esimweni samagnetic, abantu kufanele banakekele ukuphepha kwabo siqu ngenkathi besebenza, ukuvimbela iminwe ukukhuphuka ngamandla anamandla okudonsa.
Yiziphi izici ezithinta ukunemba kukazibuthe we-Nd-Fe-B we-sintered?
Izinto ezithinta ukunemba kukazibuthe we-Nd-Fe-B osikiwe ukuthi ucubungula amathuluzi, amathuluzi nobuchwepheshe bokucubungula, kanye nezinga lobuchwepheshe lomsebenzisi, njll. Ngaphezu kwalokho, ukwakheka okuncane kwezinto kunethonya elikhulu ukunemba kwemishini kazibuthe.Ngokwesibonelo, uzibuthe nge isigaba main okusanhlamvu amaholoholo, indawo othambekele ukuba pitting at isimo machining;uzibuthe ukukhula okusanhlamvu okungavamile, isimo somshini womshini sithambekele ekubeni nomgodi wezintuthwane;ukuminyana, ukwakheka kanye nokuma akulingani, usayizi we-chamfer ngeke ulingane;uzibuthe onokuqukethwe kwe-oksijini okuphezulu uyaphuka, futhi uthambekele ekunqamukeni i-engeli phakathi nenqubo yomshini;isigaba esiyinhloko sikazibuthe sokusanhlamvu okuqinile kanye nokusabalalisa kwesigaba esicebile se-Nd akufani, ukunamathela kwe-uniform plating ne-substrate, ukufana kokuqina kwe-coating, kanye nokumelana nokugqwala kwe-coating kuyoba ngaphezu kwesigaba esiyinhloko sokusanhlamvu okuhle nokusatshalaliswa okufanayo kwe-Nd. umehluko wesigaba esicebile uzibuthe.Ukuze uthole imikhiqizo kazibuthe ye-Nd-Fe-B enembayo ephezulu, unjiniyela okhiqiza izinto ezibonakalayo, unjiniyela womshini nomsebenzisi kufanele baxhumane ngokugcwele futhi babambisane.