Sintered hlau nplaum feem ntau siv cov hlau ntshiab los yog cov khoom siv nruab nrab los ua cov khoom siv raw. Lawv siv lub hauv paus ntsiab lus ntawm electromagnetic induction cua sov ntawm alternating magnetic teb los tsim eddy tam sim no nyob rau hauv cov ntaub ntawv raw. Cov ntaub ntawv raw yog smelted los ntawm nruab nrab thiab tsawg zaus induction nyob rau hauv lub tshuab nqus tsev los yog inert gas ib puag ncig kom cov ntaub ntawv raw yog rhuab thiab melted. Lub yaj yog stirred rau homogenize nws. Cov ntsiab lus melting ntawm cov hlau tsis tshua muaj hauv ntiaj teb yog nyob nruab nrab ntawm 800 thiab 1500 degree, Fe thiab Co yog 1536 degree thiab 1495 degree feem, thiab B ntshiab yog siab li 2077 degree. Cov ntsiab lus melting ntawm qee qhov siab melting point hlau siv los ua cov khoom ntxiv xws li Ti, Cr, Mo, lossis Nb yog nyob ntawm 1600 ~ 3400 degree. Noj rau hauv tus account qhov kev tsuj ntawm volatilization ntawm lub ntiaj teb tsis tshua muaj cov ntsiab lus, lub melting kub feem ntau yog tswj ntawm 1000 ~ 1600 degree. Cov ntsiab lus siab melting point yog melted los ntawm alloying ntawm lub ntiaj teb tsis tshua muaj hlau yaj, los yog alloys ntawm high-melting-point ntsiab (feem ntau yog hlau alloys) ncaj qha siv raws li raw cov ntaub ntawv, xws li B-Fe (melting point ~ 1500 degree), Nb-Fe (melting point ~ 1600 degree) alloy, thiab lwm yam. Kom ntseeg tau tias qhov chaw qis qis rau smelting thiab casting, nws yog ib qho tsim nyog yuav tsum khiav tawm lub melting thiab casting rauv lub cev thiab tag nrho deflate cov khoom thiab cov ntaub ntawv raw hauv lub cub tawg. Lub tshuab nqus tsev feem ntau ncav cuag 10-2~10-3.
Lub qhov cub lub cev yog rhuab Lub siab nce tus nqi (tso pa tawm sab hauv thiab sab nraud cua to) kuj yuav tsum tau tswj nyob rau theem qis. Piv txwv li, rau lub qhov cub smelting nrog lub peev xwm ntawm 1t, lub siab nce tus nqi yuav tsum qis dua 5 × 10-4~ 1 × 10-3 L / s. Lub tshuab nqus tsev smelting tuaj yeem ua kom tag nrho cov kua molten, tshem tawm cov dej npau qis thiab cov roj teeb meem, thiab txhim kho cov purity ntawm cov hlau. Txawm li cas los xij, vim tias qhov vapor siab ntawm cov hlau tsis tshua muaj hauv ntiaj teb tsawg heev (tsawg dua 1 Pa), qhov kev poob qis yog qhov tseem ceeb, yog li nws feem ntau yog siv thaum lub sij hawm smelting. Lub tshuab ua kom sov lub cev yog ntim nrog cov roj inert kom ua rau huab cua ambient siab los suppress lub volatilization ntawm tsawg ntiaj teb. Nws yooj yim dua los siv cov pa roj purity argon, uas feem ntau tau ntim rau qib 50kPa. Tom qab cov hlau yaj yog homogenized, vented, thiab slagging tiav lawm, casting tuaj yeem pib. Alloy casting yog txheej txheem tseem ceeb heev vim tias muaj pes tsawg leeg, crystallization xeev, thiab spatial faib ntawm cov theem yog qhov tseem ceeb rau kev ua haujlwm ntawm cov hlau nplaum sintered. Lub alloy ingot tau ntsib hnyav "cannonballs", 20mm tuab "phau ntawv", thiab 5mm "pancakes" "Tam sim no, nws tau tsim kom ceev-teeb flakes nrog ib tug tuab ntawm 0.3mm. Kev lag luam insiders tau ua ntau yam kev siv zog kom tsis txhob muaj kev sib cais. thiab tiam ntawm impurity theem thiab tsim nyog faib cov faib ntawm neodymium-nplua nuj theem.
1. Smelting
Cov ntaub ntawv tsis tshua muaj hauv ntiaj teb feem ntau siv cov hlau ntshiab thiab cov hlau tsis tshua muaj hauv ntiaj teb feem ntau raug xaiv vim yog vim li cas tus nqi, xws li praseodymium thiab neodymium hlau, lanthanum thiab cerium hlau, sib xyaw tsis tshua muaj ntiaj teb, thiab dysprosium ferroalloys, thiab lwm yam. Cov ntsiab lus siab melting point (xws li: B, Mo, Nb, thiab lwm yam) Nws yog feem ntau ntxiv rau hauv daim ntawv ntawm ferroalloy. Nd-Fe-B hlau nplaum muaj cov yam ntxwv ntawm ntau theem hlau. Nd-nplua nuj theem yog qhov tsim nyog rau kev sib koom tes siab, thiab theem B-nplua nuj yuav tsum tau sib koom ua ke. Yog li ntawd, lub ntiaj teb tsis tshua muaj thiab B hauv cov qauv qub feem ntau yuav tsum siab tshaj qhov zoo ntawm R2Fe14B, tab sis qee zaum los kho qhov muaj pes tsawg leeg ntawm cov ciam teb theem (tshwj xeeb tshaj yog thaum Cu, Al, thiab Ga ntxiv), B. cov ntsiab lus yog me ntsis qis dua qhov zoo tivthaiv. Vim yog cov tshuaj tiv thaiv ntawm cov hlau tsis tshua muaj hauv ntiaj teb thiab cov khoom siv crucible thiab volatilization thaum lub sij hawm smelting thiab sintering, qee qhov poob ntawm cov hlau tsis tshua muaj hauv ntiaj teb yuav tsum xav txog thaum tsim. Txhawm rau txo cov ntsiab lus impurity hauv cov hlau, cov purity ntawm cov ntaub ntawv raw yuav tsum nruj me ntsis tswj, thiab cov oxide txheej thiab cov ntaub ntawv txuas rau ntawm qhov chaw yuav tsum tau muab tshem tawm tag nrho. Qhov chaw tshav kub ntawm qhov nruab nrab thiab tsawg zaus induction melting yog induced eddy tam sim no tsim nyob rau hauv cov ntaub ntawv raw los ntawm alternating magnetic teb. Cov nyhuv ntawm daim tawv nqaij ntawm eddy tam sim no ua rau cov tam sim no mloog zoo rau ntawm cov khoom siv raw. Yog tias qhov loj ntawm cov khoom siv raw khoom loj dhau lawm, cov eddy tam sim no tsis tuaj yeem nkag mus rau hauv nruab nrab ntawm qhov thaiv, thiab tsuas yog cov tub ntxhais tuaj yeem yaj los ntawm kev kub nyhiab, uas yog qhov tsis muaj tseeb hauv kev tsim khoom tiag tiag. Yog li ntawd, qhov loj ntawm cov khoom siv raw yuav tsum tau hloov kho raws li qhov kev xaiv zaus thiab tswj tau li 3 mus rau 6 npaug ntawm qhov tob ntawm daim tawv nqaij. Daim duab hauv qab no qhia txog kev sib raug zoo ntawm lub zog zaus - qhov tob ntawm daim tawv nqaij - thiab cov khoom siv raw. Nws tuaj yeem pom tias qhov ntau zaus, qhov tseem ceeb ntawm daim tawv nqaij ua haujlwm, thiab qhov me me ntawm cov khoom siv raw yuav tsum tau ua.
| Fais fab zaus / Hz | 50 | 150 | 1000 | 2500 | 4000 | 8000 |
| Qhov tob ntawm daim tawv nqaij / mm | 73 | 42 | 16 | 10 | 8 | 6 |
| Qhov zoo tshaj plaws Raw Material Size/mm | 220-440 | 125-250 | 50-100 | 30-60 | 25-50 | 15-35 |
Kev xaiv ntawm melting zaus yog ua rau lwm qhov tseem ceeb ntawm induction melting - electromagnetic stirring, uas siv cov kev sib cuam tshuam ntawm lub zog ntawm molten hlau thiab alternating magnetic teb los txhawb lub melting ntawm unmelted solids thiab homogenization ntawm cov hlau molten. Lub zog electromagnetic Qhov magnitude yog inversely proportional rau lub square root ntawm zaus tam sim no. Ntau zaus ntau zaus yuav ua rau cov electromagnetic nplawm tsis muaj zog ntawm cov khoom siv hluav taws xob hloov pauv. Cov zaus siv nyob rau hauv qhov tseeb ntau lawm yog nyob ib ncig ntawm 1000 ~ 2500Hz, thiab cov khoom siv raw yuav tsum tau tswj hauv qab 100 hli.
Lub stacking ntawm raw cov ntaub ntawv nyob rau hauv lub crucible yuav tsum coj mus rau hauv tus account lub spatial faib ntawm induced magnetic teb thiab kub thaum lub sij hawm melting txheej txheem. Feem ntau, induction kauj yog qhov txhab nyob ib ncig ntawm sab nraud ntawm lub crucible. Cov hlau nplaum muaj zog tshaj plaws nyob rau sab hauv ntawm lub crucible thiab maj mam tsis muaj zog mus rau qhov chaw, tab sis ob sab, hauv qab, thiab sab saum toj ntawm lub crucible Qhov qhib yog lub ntsiab rau cua sov kom dim, yog li qhov kub ntawm sab qis ntawm lub crucible. yog nyob rau hauv nruab nrab, qhov kub ntawm lub sab sauv txheej thiab nruab nrab ntawm lub hauv qab yog qis dua, thiab qhov kub ntawm qhov nruab nrab yog qhov siab tshaj plaws. Yog li ntawd, thaum thauj khoom, nws raug nquahu kom muab cov khoom me me ntawm cov ntaub ntawv uas tsis tshua muaj melting point ntom ntom rau hauv qab ntawm lub crucible; high-melting point cov ntaub ntawv thiab cov ntaub ntawv loj yuav tsum muab tso rau hauv nruab nrab thiab qis; cov khoom loj ntawm cov ntaub ntawv uas tsis tshua muaj melting point yuav tsum tau muab tso rau hauv qhov chaw sab sauv thiab xoob kom tsis txhob muaj kev sib tsoo. Niaj hnub no, nruam smelting-casting tshuab tau dav siv. Cov ntaub ntawv raw yog txuas ntxiv mus rau lub crucible ntawm qhov kub thiab txias los ntawm lub chamber them. Txhawm rau tswj cov volatilization ntawm cov ntaub ntawv tsis tshua muaj hauv ntiaj teb, cov hlau ntshiab feem ntau yog ntxiv ua ntej kom yaj nws, tom qab ntawd cov hlau melting siab los yog alloys tau ntxiv raws li qhov sib txawv, thiab thaum kawg, cov av tsis tshua muaj ntxiv.
2. Casting
Tsis tshua muaj lub ntiaj teb binary los yog ternary alloys inevitably tsim -Co los yog -Fe theem nyob rau hauv qeeb (ze equilibrium) txias txias. Lawv cov khoom sib nqus mos ntawm chav tsev kub yuav ua rau cov hlau nplaum ruaj khov ntawm cov hlau nplaum thiab yuav tsum tau txias sai sai los tiv thaiv lawv qhov tsim.
Yuav kom ua tiav qhov yuav tsum tau ua kom txias txias, tsoos ingot pwm casting tshuab tau ua hauj lwm los txo cov thickness ntawm cov hlau ingot. Qhov zoo ntawm ingot pwm casting yog cov cuab yeej siv qis, kev ua haujlwm yooj yim, thiab muaj peev xwm ua tau raws li cov khoom siv hlau nplaum dav dav. Qhov tsis zoo yog qhov loj ntawm cov nplej tsis sib npaug thiab -Co lossis -Fe theem feem ntau precipitate. Kev kho cua sov mus sij hawm ntev ntawm cov hlau ingots ntawm qhov kub hauv qab lub melting point ntawm cov hlau tuaj yeem pab tshem tawm -Co lossis -Fe theem, tab sis nws yuav ua rau cov tsub zuj zuj ntawm Nd-nplua nuj theem, uas tsis tsim nyog rau kev pom zoo ntawm cov nplej. ciam teb theem nyob rau hauv sintered hlau nplaum.
Txhawm rau txo qhov tuab ntawm cov hlau nplaum, cov qauv "disc-scraper" zoo ib yam li nthuav tawm lub pancake, ua rau cov hlau tuab txog li 1cm. Txawm li cas los xij, qhov nce hauv cheeb tsam alloy coj teeb meem ntau rau kev sau cov khoom siv hluav taws xob loj loj. . Lwm txoj kev txhim kho thev naus laus zis zoo mus rau qhov tsis sib xws, pib los ntawm qhov txias txias heev rau kev npaj ceev ceev-quenching Nd-Fe-B alloys, thiab sim txo qhov txias txias los npaj ceev-txias crystalline alloys, uas yog hu ua strips. technology ntawm casting los yog ceev-flakes flakes (strip casting los yog SC) tau los ua. Nws nchuav cov molten alloy los ntawm kev hloov pauv mus rau lub voj voog dej txias sai sai kom tau txais 0.2 ~ 0.6mm thickness, zoo tagnrho theem muaj pes tsawg leeg thiab kev ntxhib los mos. Alloy flakes. Nyob rau hauv cov qauv sawb-cam khwb cia hlau, cov qauv kev faib tawm ntawm Nd-nplua nuj theem thiab kev tawm tsam ntawm -Fe txo tag nrho cov ntsiab lus tsis tshua muaj hauv ntiaj teb, uas muaj txiaj ntsig zoo kom tau txais cov hlau nplaum ua haujlwm siab thiab txo cov nqi hlau nplaum; Qhov tsis zoo yog vim qhov txo qis ntawm qhov ntim feem ntawm Nd-nplua nuj theem, piv nrog cov hlau nplaum uas tsim los ntawm ingot pwm casting, qhov brittleness ntawm cov hlau nplaum nce thiab tom qab ua tiav yuav nyuaj dua.
