Magnetsua kom pom lub zog tsis pom kev uas rub cov hlau, suav nrog hlau, npib tsib xee, thiab cobalt. Thaum tshav kub kub cuam tshuam li cas hlau nplaum ua haujlwm zoo. Thaum nws tau kub, cov hlau nplaum yuav qaug zog. Thaum tshav kub kub heev, lawv nres ua hlau nplaum. To taub qhov kub thiab txias qhov cuam tshuam tseem ceeb.
Paub tias cov hlau nplaum cuam tshuam li cas rau cov cua sov tso cai rau peb los tsim cov khoom siv thiab cov tshuab uas ua tau zoo nyob thoob plaws ntau qhov kev ua haujlwm kub.
Kab lus no yuav provide ib tug txheej txheem cej luam ntawm hlau nplaum thiab piav qhia yuav ua li cas kub influences mus tas li hlau nplaum thiab electromagnets. Peb kuj tseem yuav tham txog Curie qhov kub thiab cov ntawv thov uas qhov kub ntawm cov hlau nplaum yog qhov tseem ceeb tsim qauv.
Dab tsi Ua Magnets Ua Haujlwm?
Cov hlau nplaum ua haujlwm vim yog cov khoom me me hauv hu ua electrons. Electrons ua zoo li me me spinning hlau nplaum. Hauv ntau cov khoom, electrons tig txhua txoj kev random. Tab sis nyob rau hauv cov ntaub ntawv hlau nplaum, cov electron tig mus.
Cov kev sib dhos ua ke ua ib qho chaw sib nqus tag nrho nrog ob qhov kawg - sab qaum teb thiab sab qab teb ncej. Cov ncej sib txawv nyiam ib leeg, zoo li sab qaum teb thiab sab qab teb. Tab sis tib tus ncej tawm tsam rau ob sab qaum teb.
Cov hlau nplaum muaj zog npaum li cas nyob ntawm seb nws tau ua li cas. Qee cov ntaub ntawv khaws cia lawv cov electron spin nyob zoo dua li lwm tus. Qhov kev muaj peev xwm tiv thaiv cov spin tau sib xyaw yog hu ua retentivity. Siab retentivity ua rau muaj zog hlau nplaum. Kev sib raug zoo ntawm zillions ntawm electrons spinning ua ke tso cai rau cov hlau nplaum lo rau cov hlau!
Permanent Magnets vs. Electromagnets
Ob hom hlau nplaum muaj nyob, suav nrog kev ruaj khov thiab electromagnetic. Cov hlau nplaum tas mus li khaws lawv cov hlau nplaum. Lawv yog ua los ntawm hlau, npib tsib xee, cobalt, thiab tsis tshua muaj hlau. Lub atomic spins nyob rau hauv cov ntaub ntawv no align spontaneously.
Electromagnets yog tsim los ntawm kev khiav hluav taws xob tam sim no los ntawm cov xaim xaim nyob ib ncig ntawm cov tub ntxhais hlau. Qhov chaw sib nqus yog tsim los ntawm qhov tam sim no hauv cov hlau. Thaum tam sim no nres, electromagnet poob nws cov hlau nplaum.
Cov hlau nplaum tas mus li thiab electromagnets raug cuam tshuam los ntawm qhov kub thiab txias. Cia peb saib txhua tus:
Yuav ua li cas kub cuam tshuam rau cov hlau nplaum tas mus li
Cov hlau nplaum tas mus li tsuas yog ua haujlwm hauv qhov kub thiab txias. Yog tias cov hlau nplaum tas mus li tau rhuab saum qhov kub thiab txias, hu ua Curie point, nws yuav plam nws cov hlau nplaum.
Ntawm Curie taw tes, cov me me txav hauv cov khoom siv hlau nplaum pib taw tes rau hauv cov lus qhia random es tsis txhob nyob hauv kab. Nws ua rau cov hlau nplaum ruaj khov tsis tuaj yeem sib nqus.
Curie Kub ntawm Common Magnet Materials
Khoom siv | Curie Kub |
Hlau | 770 degree |
Nickel | 358 degree |
Cobalt | 1121 degree |
Neodymium | 310-400 degree |
Cua sov lub hlau nplaum tas mus li saum lub Curie point ua rau nws tsis yog hlau nplaum. Saum toj no, cov atomic spin uas tsim cov hlau nplaum yog cuam tshuam. Nws ua rau cov hlau nplaum ruaj khov ntawm cov hlau, npib tsib xee, lossis cobalt kom plam txhua tus cwj pwm sib nqus.
Feem ntau, tag nrho demagnetization no tsis tuaj yeem thim rov qab hauv cov hlau nplaum ib txwm muaj. Cov hlau nplaum yuav tsum tau re-magnetized siv raug rau lwm qhov muaj zog magnetic teb.
Txawm li cas los xij, qee lub ntiaj teb tsis tshua muaj hlau nplaum ntawm neodymium lossis samarium cobalt tuaj yeem rov qab tau lawv cov hlau nplaum tom qab cua sov dhau los ntawm lawv qhov Curie point. Tab sis rov ua kom sov thiab txias los ntawm kev siv txhua hnub tuaj yeem maj mam txo cov hlau nplaum me ntsis los ntawm lub sijhawm.
Nyob rau hauv Curie qhov kub thiab txias, cov hlau nplaum ruaj khov yuav maj mam poob lub zog thaum nws kub. Thaum tshav kub kub ua rau lub atom tig ntau lub zog vibrations. Qhov kev cuam tshuam ntawm qhov sib npaug sib npaug ua rau cov hlau nplaum tsis muaj zog.
Luckily, qhov no maj mam poob ntawm hlau nplaum nrog nce kub yog thim rov qab. Thaum cov hlau nplaum ruaj khov txias, lub atomic spins realign, thiab tag nrho cov hlau nplaum rov qab los. Txawm tias me me hloov pauv ntawm ob peb degrees tuaj yeem hloov pauv lub zog hlau nplaum.
Hauv cov ntsiab lus, cov hlau nplaum ruaj khov ua haujlwm tau zoo tshaj plaws nyob rau hauv qhov ntsuas qhov ntsuas kub tsawg. Cov cua kub ntau dhau demagnetizes lawv tag nrho lossis ib nrab. Qhov kub qis dua txhim kho lub zog hlau nplaum.
Cov kws tshaj lij xav txog cov kev cuam tshuam thermal no thaum tsim cov cuab yeej siv cov hlau nplaum ruaj khov. Ua tib zoo tswj qhov kub thiab txias ua kom cov hlau nplaum ua haujlwm ntawm qhov ua tau zoo ntawm cov hlau nplaum.
Qhov kub thiab txias cuam tshuam li cas electromagnets
Electromagnets txawv ntawm cov hlau nplaum ruaj khov. Lawv cov hlau nplaum yog los ntawm cov hluav taws xob txav los ntawm cov hlau kauj. Hloov cov hluav taws xob ua rau cov hlau nplaum muaj zog lossis tsis muaj zog.
Thaum tshav kub kub cuam tshuam cov electromagnets los ntawm kev ua rau cov hlau nyuaj rau cov hluav taws xob ntws mus. Thaum cov hlau kub kub, cov hluav taws xob vibrates ntau hauv nws. Nws ua rau nws nyuaj rau cov hluav taws xob kom txav tau yooj yim hauv ib qho kev taw qhia.
Thaum hluav taws xob tsis ntws yooj yim, tsawg dua tuaj yeem hla cov hlau. Yog li, electromagnet tsis muaj zog thaum kub piv rau thaum txias.
Tab sis qhov nruab nrab kub thiab txias txias tsis cuam tshuam rau electromagnets ntau dhau. Cov hluav taws xob ntws los tsuas yog me ntsis xwb tshwj tsis yog cov hlau overheats. Lub magnetic teb tau txais me ntsis qaug zog, tsis tag nrho.
Txias lub electromagnet cia ntau ua rau hluav taws xob ntws tau yooj yim. Ib qho piv txwv yog siv kua nitrogen, uas yog -196 degree ! Nws tso cai rau cov hlau nplaum muaj zog nrog hluav taws xob tsawg. Supercool electromagnets tuaj yeem ua teb 100, 000 zaug lub ntiaj teb teb!
Hauv cov ntsiab lus, electromagnets tsis muaj zog thaum kub vim tias cov hlau tiv thaiv hluav taws xob ntau dua. Cov kub txias heev txhim kho cov hluav taws xob khiav thiab ntxiv dag zog rau cov hlau nplaum. Tab sis cov cua sov tsis tshem tawm cov hlau nplaum electromagnet zoo li cov hlau nplaum ruaj khov.
Piv txwv ntawm Temperature Effects on Magnets
Txhawm rau saib seb qhov kub li cas cuam tshuam cov hlau nplaum, cia saib qee qhov piv txwv ntawm lub ntiaj teb tiag:
● Cov hlau nplaum tub yees siv cov hlau nplaum ruaj khov ua los ntawm ferrite lossis neodymium. Lawv tau pom tsis muaj zog thaum kub tab sis rov ua kom muaj hlau nplaum tag nrho thaum txias dua. Tso lawv los ntawm tshav kub zoo li lub qhov cub tuaj yeem maj mam demagnetize lawv lub sijhawm.
● Cov tshuab MRI siv cov khoom siv hluav taws xob muaj zog heev uas yog supercooled nrog kua helium. Cov cua txias tso cai rau lawv ua kom muaj zog 3 Tesla magnetic teb uas xav tau rau kev soj ntsuam lub cev kom ntxaws.
● Cov hlau nplaum loj uas siv los nqa tsheb ntawm junkyards hu ua crane hlau nplaum. Lawv nqa cov khoom hnyav uas siv lub zog sib nqus. Nyob rau hnub kub, cov hlau nplaum tsis tuaj yeem nqa nws qhov hnyav tshaj plaws vim yog cua sov, ua rau nws tsis muaj zog. Txias lub electromagnet coil tso cai rau nqa cov khoom hnyav dua.
● Me me neodymium hlau nplaum nyob rau hauv me me motors poob torque thiab tau tsawg npaum yog hais tias lub cev muaj zog overheats. Kub kub demagnetize cov hlau nplaum tas mus li nyob rau hauv lub spinning rotor. Nws ua rau lub zog sib nqus sib nqus uas ua rau lub cev muaj zog ua haujlwm.
● Sib nqus tapes thiab hard drives siv cov hlau me me los khaws cov ntaub ntawv. Thaum tshav kub kub heev jumbles li magnetic particles, erasing cov ntaub ntawv. Yog li sib nqus cia muaj qhov kub siab tshaj plaws nws tuaj yeem ua haujlwm ua ntej cov ntaub ntawv ploj.
Cov piv txwv no qhia tau hais tias qhov ntsuas kub thiab kev tswj hwm yog qhov tseem ceeb thaum ua haujlwm nrog cov hlau nplaum. Cov hlau nplaum tas mus li yuav tsum tau txias kom khaws cov khoom sib nqus. Nyob rau tib lub sij hawm, electromagnets yuav tsum tsis txhob overheating, ua kom cov hlau tsis kam, thiab txo lub zog teb.
Qhov cuam tshuam ntawm Kev Kub Kub Kub rau Magnets
Peb tau pom qhov kub thiab txias poob qis zog hlau nplaum. Yuav ua li cas yog freezing kub?
Raws li tau hais ua ntej, txo cov thermal zog pab kom ruaj khov ntawm atomic spinning hauv cov hlau nplaum ruaj khov. Yog li, cov hlau nplaum ruaj khov ua rau muaj zog dua ntawm qhov kub thiab txias.
Cov hlau nplaum neodymium txias nrog cov kua nitrogen mus rau -196 degree tuaj yeem ua rau muaj zog rub los ntawm 2-5x piv rau chav tsev kub. Lub xeev hyper-magnetized no ua rau cov ntawv thov tshiab xws li tsheb ciav hlau maglev.
Electromagnets kuj tau txais txiaj ntsig los ntawm qhov qis qis vim yog cov xov hlau tsis muaj hluav taws xob tsis zoo (superconductivity). Qhov no ua rau cov hlau nplaum loj loj los ntawm cov coils me me.
MRI thiab kev tshawb fawb tshawb fawb electromagnets tau txias los ntawm cov kua helium kom coj mus rau hauv lub peev xwm ntawm superconductors zoo li niobium-tin. Kev ua haujlwm qis-kub tso cai yooj yim rau tiam ntawm high-strength magnetic teb.
Yog li, thaum tshav kub tsis muaj zog hlau nplaum, qhov txias txias txhawb cov hlau nplaum ua haujlwm. Ob lub hlau nplaum ruaj khov thiab cov hlau nplaum tuaj yeem txhim kho los ntawm kev txo cov thermal txav ntawm qib molecular.
Qhov ntsuas kub cuam tshuam li cas rau cov qauv ntawm cov hlau nplaum?
Cov tsev me me uas tsim cov khoom sib nqus hloov thaum cua sov lossis txias. Nws cuam tshuam li cas sib nqus lawv. Cia peb tshuaj xyuas seb qhov kub hloov pauv li cas cov hlau nplaum hom ' crystal lattice thiab magnetic domains.
Cov hlau nplaum tas mus li muaj qhov me me hu ua domains. Txhua tus sau yog zoo li lub hlau nplaum me me nrog cov sib npaug sib npaug. Tab sis cov neeg nyob sib ze taw tes rau hauv txoj kev random. Cov cua sov jumbles li cov qauv zoo huv si, ua rau cov hlau nplaum tsis muaj zog. Cov kab txias tuaj yeem ua kom zoo nkauj, ntxiv dag zog rau tag nrho cov hlau nplaum.
Cov khoom sib txawv muaj cov qauv siv lead ua lattice sib txawv. Nws yog qhov sib nrug thiab kev txiav txim ntawm cov atoms. Hlau muaj ib tug qauv, thiab cobalt muaj lwm. Qhov zoo tshaj plaws domain alignment nyob ntawm txhua qhov siv lead ua lattice qhov tshwj xeeb atomic spacing thiab lub zog lub xeev.
Electromagnets yog cov xov hlau coiled rau hauv cov voj voog ntau dua li cov khoom siv. Tab sis lawv feem ntau muaj crystalline hlau los yog hlau cores. Cua sov ua rau cov atoms vibrate thiab sib nrug. Nws cuam tshuam qhov kev sib raug zoo hauv lub hauv paus, txo cov hlau nplaum. Khaws electromagnets txias tswj cov qauv zoo.
Zuag qhia tag nrho, qhov tsis pom atomic kev npaj piav qhia vim li cas hlau nplaum hloov pauv nrog qhov kub thiab txias. Cov cua sov ua rau cov qauv me me. Kev ua kom txias ua rau kev txiav txim zoo thiab ruaj khov. Nkag siab txog cov cuab yeej nanoscale no yog qhov tseem ceeb rau engineering hlau nplaum rau qhov kub thiab txias.
Xaiv cov khoom siv hlau nplaum zoo
Cov hlau nplaum tas mus li yog ua los ntawm hlau, npib tsib xee, cobalt, thiab cov hlau tsis tshua muaj hauv ntiaj teb sib xyaw. Engineers xaiv cov khoom raws li qhov kub thiab txias, lub zog, thiab cov nqi xav tau.
Alnico hlau nplaum muaj hlau, txhuas, nickel, thiab cobalt. Lawv ua hauj lwm txog li 600 degree, tab sis lawv lub zog magnetic teb yog nruab nrab, nyob ib ncig ntawm 0.5-1.3T.
Ceramic lossis ferrite hlau nplaum siv barium thiab strontium ferrites. Lawv yog cov nqi qis tab sis muaj lub zog meager hauv qab 0.4T.
Samarium cobalt hlau nplaum tuaj yeem ua kom muaj zog ua haujlwm siab txog 1.1T thiab ua haujlwm rau 350 degree tab sis kim.
Hlau-neodymium-boron hlau nplaum muaj qhov ua tau zoo tshaj plaws. Lawv muaj peev xwm ua teb txog li 1.4T thiab ua haujlwm rau 230 degree.
Magnetic Properties ntawm Common Permanent Magnets
Khoom siv | Max ua haujlwm Temp | Sib Nqus Field Strength | Nqi |
Alnico | 600 degree | 0.5-1.3 T | Tsawg |
Ferrite | 180 degree | <0.4 T | Tsawg heev |
Samarium Cobalt | 350 degree | Mus txog 1.1 T | Siab |
Neodymium hlau boron | 230 degree | Mus txog 1.4 T | Nruab nrab |
Rau electromagnets, tooj liab coils maximize conductivity thiab yuav tsum tau txias kom boost lub teb. Hlau cores mloog zoo rau lub magnetic teb. Nickel-coated hlau kuj tiv taus corrosion.
Neodymium lossis samarium cobalt ua haujlwm zoo tshaj plaws rau thaj chaw muaj zog tshaj txawm tias tus nqi. Qhov ntsuas kub ntawm cov hlau nplaum yuav tsum ua haujlwm hauv kev txiav txim siab cov khoom siv zoo tshaj plaws.
Kev sim lom zem nrog Magnets
Koj tuaj yeem sim cov kev tshawb fawb zoo siab hauv tsev siv cov hlau nplaum thiab ntau yam ntaub ntawv.
Chilled Magnets:
Koj tuaj yeem pom tias qhov txias txias npaum li cas ua rau cov hlau nplaum muaj zog nrog kev lom zem sim. Nqa lub tub yees hlau nplaum thiab lo rau hauv koj lub fridge. Tso cov hlau nplaum rau ntawm lub fridge rau ob peb teev. Tom qab ntawd, siv nws los khaws cov ntawv clips lossis lwm yam hlau nplaum.
Cov hlau nplaum puas zoo li nws rub nyuaj rau ntawm cov khoom hlau thaum txias? Qhov kub qis hauv lub tub yees ua rau cov hlau nplaum muaj zog dua ib ntus. Tab sis qhov kev txhawb nqa hauv lub zog sib nqus no yuav tsis nyob mus ib txhis.
Tom qab cov hlau nplaum sov rau chav sov sab nraum lub tub yees, nws cov hlau nplaum yuav rov qab mus rau qhov qub. Nws yog qhov txias li cas ob peb degrees ntawm qhov kub thiab txias hloov tuaj yeem cuam tshuam rau qhov pom tsis pom kev sib nqus!
Baked Magnets:
Ntawm no yog ib qho kev sim los qhia tias cua sov ua rau cov hlau nplaum tsis muaj zog. Nqa qee cov hlau nplaum thiab ci rau hauv qhov cub ntawm qhov kub ntawm 150 degree F (65 degree) rau 10-20 feeb. Tom qab ci, tshem cov hlau nplaum thiab sim lawv lub zog rub.
Sim khaws cov ntawv clips lossis cov ntsia hlau me me. Koj yuav tsum pom tias cov cua sov ua rau cov hlau nplaum tsis muaj zog. Lub ci txo lawv cov hlau nplaum rub hauv qhov cub sov. Nws qhia tau hais tias txawm tias cua sov me me tuaj yeem cuam tshuam qhov tsis pom kev sib nqus ntawm cov hlau nplaum ruaj khov.
Magnetic Attractions:
Nqa ob lub zog hlau nplaum. Muab ib daim hlau nplaum rau ib pob dej khov kom nws txias heev. Kaw lwm cov hlau nplaum rau ib lub hnab ntim tes, yog li nws tau zoo thiab sov. Tam sim no, sim maj mam nqa ob lub hlau nplaum rau ib leeg.
Ua tib zoo saib yuav ua li cas muaj zog cov ncej sab nraud nyiam thiab ua ke. Koj yuav pom tias nws nyuaj dua rau cov hlau nplaum sov kom nyiam cov hlau nplaum txias.
Cov hlau nplaum txias tseem muaj zog hlau nplaum, tab sis cov cua sov ua rau cov hlau nplaum tsis muaj zog hauv cov hlau nplaum sov. Nws pom tau tias qhov kub siab dua txo qhov pom tsis pom kev sib nqus ntawm cov hlau nplaum. Zoo nkauj!
Melted Magnets:
Nrog rau cov neeg laus pab, koj tuaj yeem qhia tau tias cov hlau nplaum poob lawv cov hlau nplaum li cas thaum cua sov ntau dhau. Siv cov phaj kub los yog qhov cub ua tib zoo kom sov cov hlau nplaum dhau 770 degree (1418 degree F). Qhov no yog siab dua li lawv qhov kub thiab txias Curie, qhov chaw uas lawv tsis ua hlau nplaum.
Tom qab cua sov cov hlau nplaum ntau heev, nws yuav tsum tsis txhob lo rau cov khoom hlau lossis lwm yam hlau nplaum!
Kev ua si nrog cov hlau nplaum thiab qhov kub thiab txias tuaj yeem ua rau muaj kev phom sij, yog li muab tus neeg laus los pab saib xyuas cov khoom kom nyab xeeb. Tab sis nws yog qhov zoo kom pom qhov kub npaum li cas tuaj yeem tshem tawm cov hlau nplaum tsis pom lub zog sib nqus. Nco ntsoov ceev faj heev, thiab tsuas yog ua cov kev sim nrog cov neeg laus saib xyuas kom raug.
Xaus
Kub heev cuam tshuam cov hlau nplaum. Cov hlau nplaum tas mus li zoo li hlau lossis neodymium poob tag nrho cov hlau nplaum saum Curie point. Qhov txias txias ua kom lawv lub zog ua haujlwm.
Electromagnets maj mam poob qis thaum kub dua vim qhov hluav taws xob qis dua. Tab sis txias boosts superconducting electromagnets mus rau siab heev teb. Ua tib zoo tswj qhov kub thiab txias yog qhov tseem ceeb. Khaws cov hlau nplaum ruaj khov kom deb ntawm huab cua kub khaws cov hlau nplaum.
Txias electromagnets ua rau muaj zog sib nqus teb. Kev siv kub thiab txias qhib cov ntawv thov sib nqus tshiab thoob plaws kev tshawb fawb, tshuaj, thiab engineering.
FAQs txog Yuav Ua Li Cas Kub Kub cuam tshuam cov hlau nplaum
Kuv tuaj yeem qhia tau li cas yog tias cov hlau nplaum tau cuam tshuam los ntawm qhov kub thiab txias?
Ntsuam xyuas cov hlau nplaum lub zog los ntawm kev ntsuas nws cov magnetic teb los yog muaj peev xwm nqa tau qhov hnyav. Sib piv cov kev qhia tshwj xeeb los txiav txim siab qhov poob ntawm cov hlau nplaum.
Curie qhov kub ntawm cov hlau nplaum yog dab tsi?
Curie kub yog qhov pib qhov twg cov khoom poob nws cov khoom sib nqus mus tas li vim muaj kev cuam tshuam thermal.