1 Daim ntawv thov thiab kev tshawb fawb txog kev nce qib ntawm silicon carbide txheej hauv cov ntaub ntawv carbon/carbon thermal field
1.1 Daim ntawv thov thiab kev tshawb fawb nce qib hauv kev npaj crucible
Hauv ib qho crystal thermal teb, lubcarbon / carbon hlaufeem ntau yog siv ua lub nkoj nqa khoom siv silicon thiab nyob rau hauv kev sib cuag nroglub pob zeb quartz, raws li pom hauv Daim Duab 2. Qhov kub ua haujlwm ntawm cov pa roj carbon / carbon crucible yog li 1450 ℃, uas raug rau ob zaug erosion ntawm cov khoom silicon (silicon dioxide) thiab silicon vapor, thiab thaum kawg lub crucible ua nyias lossis muaj lub nplhaib tawg, ua rau lub crucible tsis ua haujlwm.
Ib qho txheej txheem sib xyaw ua ke carbon/carbon composite crucible tau npaj los ntawm cov txheej txheem tshuaj lom neeg thiab cov tshuaj tiv thaiv hauv qhov chaw. Cov txheej txheem sib xyaw ua ke tau ua los ntawm silicon carbide txheej (100 ~ 300 μm), silicon txheej (10 ~ 20 μm) thiab silicon nitride txheej (50 ~ 100 μm), uas tuaj yeem tiv thaiv kev xeb ntawm silicon vapor ntawm sab hauv ntawm carbon/carbon composite crucible. Hauv cov txheej txheem ntau lawm, qhov poob ntawm cov txheej txheem sib xyaw ua ke carbon/carbon composite crucible yog 0.04 hli ib lub cub tawg, thiab lub neej ua haujlwm tuaj yeem ncav cuag 180 lub sijhawm cub tawg.
Cov kws tshawb nrhiav tau siv txoj kev tshuaj lom neeg los tsim kom muaj ib txheej silicon carbide sib xws rau ntawm qhov chaw ntawm cov pa roj carbon / carbon composite crucible nyob rau hauv qee qhov kub thiab kev tiv thaiv cov roj nqa, siv silicon dioxide thiab silicon hlau ua cov khoom siv raw hauv lub cub tawg sintering kub siab. Cov txiaj ntsig qhia tau hais tias kev kho kub siab tsis yog tsuas yog txhim kho qhov huv thiab lub zog ntawm cov txheej sic, tab sis kuj txhim kho qhov kev tiv thaiv kev hnav ntawm qhov chaw ntawm cov pa roj carbon / carbon composite, thiab tiv thaiv kev xeb ntawm qhov chaw ntawm crucible los ntawm SiO vapor thiab volatile oxygen atoms hauv lub cub tawg monocrystal silicon. Lub neej ua haujlwm ntawm crucible tau nce 20% piv rau ntawm crucible tsis muaj sic txheej.
1.2 Daim ntawv thov thiab kev tshawb fawb kev nce qib hauv cov raj xa dej
Lub tog raj kheej qhia nyob saum lub crucible (raws li pom hauv Daim Duab 1). Hauv cov txheej txheem ntawm kev rub siv lead ua, qhov sib txawv ntawm qhov kub thiab txias ntawm sab hauv thiab sab nraud ntawm thaj teb yog loj, tshwj xeeb tshaj yog qhov chaw hauv qab yog ze tshaj plaws rau cov khoom siv silicon molten, qhov kub thiab txias yog qhov siab tshaj plaws, thiab qhov xeb los ntawm silicon vapor yog qhov loj tshaj plaws.
Cov kws tshawb nrhiav tau tsim ib txoj kev yooj yim thiab zoo tiv thaiv oxidation ntawm cov txheej txheem tiv thaiv oxidation thiab kev npaj ntawm lub raj qhia. Ua ntej, ib txheej ntawm silicon carbide whisker tau cog rau ntawm lub matrix ntawm lub raj qhia, thiab tom qab ntawd ib txheej silicon carbide sab nraud tau npaj, yog li ntawd ib txheej hloov pauv SiCw tau tsim ntawm lub matrix thiab txheej silicon carbide nto, raws li pom hauv Daim Duab 3. Tus coefficient ntawm thermal expansion yog nyob nruab nrab ntawm lub matrix thiab silicon carbide. Nws tuaj yeem txo qhov kev ntxhov siab thermal uas tshwm sim los ntawm qhov tsis sib xws ntawm thermal expansion coefficient.
Qhov kev tshuaj xyuas qhia tau hais tias nrog kev nce ntawm SiCw cov ntsiab lus, qhov loj me thiab tus lej ntawm cov kab nrib pleb hauv cov txheej txheej txo qis. Tom qab 10 teev oxidation hauv 1100 ℃ huab cua, qhov hnyav poob ntawm cov qauv txheej tsuas yog 0.87% ~ 8.87%, thiab qhov tsis kam oxidation thiab thermal shock tsis kam ntawm silicon carbide txheej tau zoo heev. Tag nrho cov txheej txheem npaj tau ua tiav tas li los ntawm kev tso tshuaj lom neeg vapor, kev npaj ntawm silicon carbide txheej tau yooj yim heev, thiab kev ua tau zoo ntawm tag nrho lub nozzle tau txhim kho.
Cov kws tshawb nrhiav tau tawm tswv yim ib txoj kev los txhim kho matrix thiab txheej saum npoo ntawm lub raj graphite rau czohr monocrystal silicon. Cov silicon carbide slurry tau txais tau coated sib npaug rau ntawm qhov chaw ntawm lub raj graphite nrog lub thickness txheej ntawm 30 ~ 50 μm los ntawm txhuam txheej lossis tshuaj tsuag txheej, thiab tom qab ntawd muab tso rau hauv lub cub tawg kub rau qhov tshuaj tiv thaiv hauv qhov chaw, qhov kub ntawm cov tshuaj tiv thaiv yog 1850 ~ 2300 ℃, thiab kev khaws cia kub yog 2 ~ 6 teev. Cov txheej sab nraud SiC tuaj yeem siv rau hauv lub cub tawg loj hlob 24 nti (60.96 cm), thiab qhov kub siv yog 1500 ℃, thiab nws pom tias tsis muaj kev tawg thiab hmoov poob rau ntawm qhov chaw ntawm lub tog raj kheej graphite tom qab 1500 teev.
1.3 Daim ntawv thov thiab kev tshawb fawb kev nce qib hauv lub tog raj kheej rwb thaiv tsev
Raws li ib qho ntawm cov khoom tseem ceeb ntawm lub monocrystalline silicon thermal field system, lub tog raj kheej rwb thaiv tsev feem ntau yog siv los txo qhov poob cua sov thiab tswj qhov kub thiab txias ntawm qhov chaw thermal field. Raws li ib feem txhawb nqa ntawm txheej rwb thaiv tsev sab hauv ntawm lub cub tawg siv lead ua ib leeg, silicon vapor corrosion ua rau slag poob thiab tawg ntawm cov khoom, uas thaum kawg ua rau cov khoom tsis ua haujlwm.
Yuav kom txhim kho qhov kev tiv thaiv xeb ntawm cov raj C/C-sic composite insulation, cov kws tshawb fawb tau muab cov khoom lag luam C/C-sic composite insulation tube uas tau npaj tseg rau hauv lub cub tawg tshuaj lom neeg, thiab npaj cov txheej txheem tso cov silicon carbide ntom ntom rau ntawm qhov chaw ntawm cov khoom lag luam C/C-sic composite insulation tube los ntawm cov txheej txheem tso cov pa tshuaj lom neeg. Cov txiaj ntsig qhia tau tias, Cov txheej txheem no tuaj yeem tiv thaiv kev xeb ntawm cov carbon fiber ntawm lub hauv paus ntawm C/C-sic composite los ntawm cov pa silicon, thiab qhov kev tiv thaiv xeb ntawm cov pa silicon tau nce 5 txog 10 npaug piv rau cov pa roj carbon/carbon composite, thiab lub neej ua haujlwm ntawm lub tog raj kheej rwb thaiv tsev thiab kev nyab xeeb ntawm qhov chaw sov tau zoo dua.
2. Xaus lus thiab kev cia siab
Txheej silicon carbideyog siv ntau dua thiab ntau dua hauv cov ntaub ntawv carbon / carbon thermal teb vim nws qhov kev tiv thaiv oxidation zoo heev ntawm qhov kub siab. Nrog rau qhov loj ntawm cov ntaub ntawv carbon / carbon thermal teb siv rau hauv monocrystalline silicon ntau lawm, yuav ua li cas txhim kho qhov sib xws ntawm silicon carbide txheej ntawm qhov chaw ntawm cov ntaub ntawv thermal teb thiab txhim kho lub neej ua haujlwm ntawm cov ntaub ntawv carbon / carbon thermal teb tau dhau los ua teeb meem ceev ceev uas yuav tsum tau daws.
Ntawm qhov tod tes, nrog rau kev txhim kho ntawm kev lag luam monocrystalline silicon, qhov kev thov rau cov khoom siv carbon / carbon thermal field siab kuj nce ntxiv, thiab SiC nanofibers kuj tseem loj hlob ntawm cov carbon fibers sab hauv thaum lub sijhawm ua haujlwm. Cov nqi ablation thiab linear ablation ntawm C/ C-ZRC thiab C/ C-sic ZrC composites npaj los ntawm kev sim yog -0.32 mg / s thiab 2.57 μm / s, feem. Cov nqi ablation thiab kab ntawm C/ C-sic -ZrC composites yog -0.24 mg / s thiab 1.66 μm / s, feem. Cov C/ C-ZRC composites nrog SiC nanofibers muaj cov khoom ablative zoo dua. Tom qab ntawd, cov teebmeem ntawm cov pa roj carbon sib txawv ntawm kev loj hlob ntawm SiC nanofibers thiab cov txheej txheem ntawm SiC nanofibers txhawb nqa cov khoom ablative ntawm C/ C-ZRC composites yuav raug kawm.
Ib qho txheej txheem sib xyaw ua ke carbon/carbon composite crucible tau npaj los ntawm cov txheej txheem tshuaj lom neeg thiab cov tshuaj tiv thaiv hauv qhov chaw. Cov txheej txheem sib xyaw ua ke tau ua los ntawm silicon carbide txheej (100 ~ 300 μm), silicon txheej (10 ~ 20 μm) thiab silicon nitride txheej (50 ~ 100 μm), uas tuaj yeem tiv thaiv kev xeb ntawm silicon vapor ntawm sab hauv ntawm carbon/carbon composite crucible. Hauv cov txheej txheem ntau lawm, qhov poob ntawm cov txheej txheem sib xyaw ua ke carbon/carbon composite crucible yog 0.04 hli ib lub cub tawg, thiab lub neej ua haujlwm tuaj yeem ncav cuag 180 lub sijhawm cub tawg.
Lub sijhawm tshaj tawm: Lub Ob Hlis-22-2024