Cov khoom siv silicon carbide (SiC) uas muaj cov khoom siv siab heev tau tshwm sim los ua cov khoom siv zoo tshaj plaws rau cov khoom tseem ceeb hauv kev lag luam semiconductor, aerospace, thiab tshuaj lom neeg vim lawv cov thermal conductivity zoo heev, kev ruaj khov tshuaj lom neeg, thiab lub zog kho tshuab. Nrog rau kev thov ntau ntxiv rau cov khoom siv ceramic uas ua haujlwm tau zoo, tsis muaj kuab paug, kev tsim cov thev naus laus zis npaj tau zoo thiab nthuav dav rau cov khoom siv SiC uas muaj cov khoom siv siab heev tau dhau los ua qhov kev tshawb fawb thoob ntiaj teb. Daim ntawv no tshuaj xyuas cov txheej txheem npaj tseem ceeb tam sim no rau cov khoom siv SiC uas muaj cov khoom siv siab heev, suav nrog recrystallization sintering, pressureless sintering (PS), hot pressing (HP), spark plasma sintering (SPS), thiab additive manufacturing (AM), nrog rau kev sib tham txog cov txheej txheem sintering, cov yam ntxwv tseem ceeb, cov khoom siv, thiab cov teeb meem uas twb muaj lawm ntawm txhua txoj kev.
Daim ntawv thov SiC ceramics hauv cov tub rog thiab engineering teb
Tam sim no, cov khoom siv ceramic SiC uas muaj cov khoom siv siab purity tau siv dav hauv cov khoom siv tsim silicon wafer, koom nrog cov txheej txheem tseem ceeb xws li oxidation, lithography, etching, thiab ion implantation. Nrog rau kev nce qib ntawm cov thev naus laus zis wafer, kev nce qhov loj ntawm wafer tau dhau los ua qhov sib txawv tseem ceeb. Qhov loj ntawm wafer tam sim no yog 300 mm, ua tiav qhov sib npaug zoo ntawm tus nqi thiab peev xwm tsim khoom. Txawm li cas los xij, tsav los ntawm Moore's Law, kev tsim khoom loj ntawm 450 mm wafers twb nyob rau ntawm daim ntawv teev npe. Cov wafers loj dua feem ntau xav tau lub zog siab dua los tiv thaiv kev warping thiab deformation, ntxiv rau kev tsav tsheb qhov kev thov loj hlob rau cov khoom siv ceramic SiC loj, muaj zog siab, purity siab. Nyob rau hauv xyoo tas los no, kev tsim khoom ntxiv (3D luam ntawv), ua ib qho thev naus laus zis prototyping sai uas tsis xav tau pwm, tau ua pov thawj muaj peev xwm loj heev hauv kev tsim cov khoom siv ceramic SiC uas muaj cov qauv nyuaj vim nws cov txheej txheem tsim thiab cov peev xwm tsim qauv yooj ywm, nyiam kev mloog dav dav.
Tsab ntawv no yuav tshuaj xyuas tsib txoj kev npaj rau cov khoom siv SiC uas muaj cov khoom huv si—kev sintering rov ua dua tshiab, kev sintering tsis muaj siab, kev nias kub, kev sintering plasma spark, thiab kev tsim khoom ntxiv—tsom mus rau lawv cov txheej txheem sintering, cov tswv yim ua kom zoo dua qub, cov yam ntxwv ntawm kev ua haujlwm ntawm cov khoom siv, thiab kev cia siab rau kev siv hauv kev lag luam.
Cov khoom siv raw khoom uas muaj purity silicon carbide siab
I. Kev Rov Ua Dua Sintering
Recrystallized silicon carbide (RSiC) yog cov khoom siv SiC siab-purity npaj tsis muaj cov khoom pab sintering ntawm qhov kub siab ntawm 2100–2500 ° C. Txij li thaum Fredriksson thawj zaug pom qhov tshwm sim recrystallization hauv xyoo pua 19th lig, RSiC tau txais kev saib xyuas tseem ceeb vim nws cov ciam teb huv si thiab tsis muaj cov iav thiab cov khoom tsis huv. Thaum kub siab, SiC ua rau muaj kev ntxhov siab ntawm cov pa dej, thiab nws cov txheej txheem sintering feem ntau cuam tshuam nrog cov txheej txheem evaporation-condensation: cov noob zoo evaporate thiab redeposit rau ntawm qhov chaw ntawm cov noob loj dua, txhawb kev loj hlob ntawm caj dab thiab kev sib txuas ncaj qha ntawm cov noob, yog li ua kom cov khoom siv muaj zog.
Xyoo 1990, Kriegesmann tau npaj RSiC nrog qhov ceev ntawm 79.1% siv slip casting ntawm 2200 ° C, nrog rau qhov seem ntawm qhov qhia txog microstructure uas muaj cov noob loj thiab cov qhov hws. Tom qab ntawd, Yi et al. siv gel casting los npaj cov lub cev ntsuab thiab sintered lawv ntawm 2450 ° C, tau txais RSiC ceramics nrog qhov ceev ntawm 2.53 g / cm³ thiab lub zog flexural ntawm 55.4 MPa.
Qhov SEM tawg nto ntawm RSiC
Piv rau cov SiC ntom ntom, RSiC muaj qhov ceev qis dua (kwv yees li 2.5 g / cm³) thiab kwv yees li 20% qhib porosity, txwv nws cov kev ua tau zoo hauv cov ntawv thov muaj zog siab. Yog li ntawd, kev txhim kho qhov ceev thiab cov khoom siv kho tshuab ntawm RSiC tau dhau los ua qhov tseem ceeb ntawm kev tshawb fawb. Sung et al. tau tawm tswv yim rau kev nkag mus rau hauv cov silicon molten rau hauv cov pa roj carbon / β-SiC sib xyaw ua ke thiab recrystallizing ntawm 2200 ° C, ua tiav kev tsim cov qauv network uas muaj cov noob loj α-SiC. Qhov tshwm sim RSiC tau ua tiav qhov ceev ntawm 2.7 g / cm³ thiab lub zog flexural ntawm 134 MPa, tswj kev ruaj khov zoo heev ntawm qhov kub siab.
Txhawm rau txhim kho qhov ceev ntxiv, Guo et al. siv polymer infiltration thiab pyrolysis (PIP) thev naus laus zis rau ntau yam kev kho mob ntawm RSiC. Siv PCS / xylene cov kua thiab SiC / PCS / xylene slurries ua infiltrants, tom qab 3-6 PIP voj voog, qhov ceev ntawm RSiC tau zoo dua (txog li 2.90 g / cm³), nrog rau nws lub zog flexural. Tsis tas li ntawd, lawv tau tawm tswv yim ib txoj kev npaj cyclic sib xyaw PIP thiab recrystallization: pyrolysis ntawm 1400 ° C ua raws li recrystallization ntawm 2400 ° C, ua kom zoo tshem tawm cov khoom thaiv thiab txo porosity. Cov khoom siv RSiC kawg tau txais qhov ceev ntawm 2.99 g / cm³ thiab lub zog flexural ntawm 162.3 MPa, qhia txog kev ua tau zoo heev.
Cov duab SEM ntawm qhov kev hloov pauv ntawm microstructure ntawm polished RSiC tom qab polymer impregnation thiab pyrolysis (PIP) -recrystallization cycles: Pib RSiC (A), tom qab thawj PIP-recrystallization cycle (B), thiab tom qab thib peb lub voj voog (C)
II. Kev Sintering Tsis Muaj Siab
Cov khoom siv ua los ntawm silicon carbide (SiC) uas tsis muaj zog feem ntau yog siv cov hmoov SiC uas muaj qhov huv siab, zoo heev ua cov khoom siv raw, nrog rau cov khoom siv pab sintering me me ntxiv, thiab sintered hauv huab cua inert lossis lub tshuab nqus tsev ntawm 1800–2150 ° C. Txoj kev no yog qhov tsim nyog rau kev tsim cov khoom siv ceramic loj thiab muaj cov qauv nyuaj. Txawm li cas los xij, vim tias SiC feem ntau yog cov khoom sib txuas ua ke, nws tus kheej-diffusion coefficient qis heev, ua rau kev sib sau ua ke nyuaj yam tsis muaj cov khoom siv pab sintering.
Raws li lub tshuab sintering, pressureless sintering tuaj yeem muab faib ua ob pawg: pressureless liquid-phase sintering (PLS-SiC) thiab pressureless solid-state sintering (PSS-SiC).
1.1 PLS-SiC (Kev Sintering Ua Kua)
Feem ntau PLS-SiC raug sintered hauv qab 2000 ° C los ntawm kev ntxiv kwv yees li 10 wt.% ntawm cov khoom siv eutectic sintering (xws li Al₂O₃, CaO, MgO, TiO₂, thiab cov pa roj av tsis tshua muaj RE₂O₃) los tsim cov kua theem, txhawb kev hloov pauv ntawm cov khoom me me thiab kev hloov pauv loj kom ua tiav kev sib sau ua ke. Cov txheej txheem no yog qhov tsim nyog rau cov khoom siv SiC hauv kev lag luam, tab sis tsis muaj lus ceeb toom txog SiC uas muaj kev ntshiab siab ua tiav los ntawm kev sintering theem kua.
1.2 PSS-SiC (Kev Sintering Khoom)
PSS-SiC muaj kev sib xyaw ua ke ntawm cov khoom khov kho ntawm qhov kub siab tshaj 2000 ° C nrog kwv yees li 1 wt.% ntawm cov khoom ntxiv. Cov txheej txheem no feem ntau yog nyob ntawm kev sib kis ntawm atomic thiab kev hloov pauv ntawm cov noob uas tsav los ntawm qhov kub siab kom txo cov zog ntawm qhov chaw thiab ua tiav kev sib xyaw. Lub kaw lus BC (boron-carbon) yog ib qho kev sib xyaw ua ke ntawm cov khoom ntxiv, uas tuaj yeem txo cov zog ntawm cov noob thiab tshem tawm SiO₂ ntawm qhov chaw SiC. Txawm li cas los xij, cov khoom ntxiv BC ib txwm muaj feem ntau qhia txog cov khoom seem, txo qhov huv ntawm SiC.
Los ntawm kev tswj cov ntsiab lus ntxiv (B 0.4 wt.%, C 1.8 wt.%) thiab sintering ntawm 2150 ° C rau 0.5 teev, cov khoom siv SiC ceramics uas muaj kev ntshiab siab nrog kev ntshiab ntawm 99.6 wt.% thiab qhov ceev ntawm 98.4% tau txais. Cov qauv me me qhia txog cov noob columnar (qee qhov ntev tshaj 450 µm), nrog cov qhov me me ntawm cov ciam teb noob thiab cov khoom graphite hauv cov noob. Cov khoom siv ceramics tau pom lub zog flexural ntawm 443 ± 27 MPa, lub modulus elastic ntawm 420 ± 1 GPa, thiab lub coefficient thermal expansion ntawm 3.84 × 10⁻⁶ K⁻¹ hauv qhov ntau ntawm chav tsev kub txog 600 ° C, qhia txog kev ua tau zoo heev.
Microstructure ntawm PSS-SiC: (A) SEM duab tom qab polishing thiab NaOH etching; (BD) BSD duab tom qab polishing thiab etching
III. Kub Nias Sintering
Kev nias kub (HP) sintering yog ib txoj kev densification uas siv cua sov thiab uniaxial siab rau cov khoom siv hmoov tib lub sijhawm nyob rau hauv qhov kub thiab txias siab. Kev nias siab ua rau cov qhov tsim thiab txwv tsis pub cov noob loj hlob, thaum qhov kub siab txhawb nqa kev sib xyaw ntawm cov noob thiab kev tsim cov qauv ntom ntom, thaum kawg tsim cov khoom siv SiC ceramics uas muaj qhov ceev ceev, siab purity. Vim yog qhov xwm txheej ntawm kev nias, cov txheej txheem no feem ntau ua rau cov noob anisotropy, cuam tshuam rau cov khoom siv kho tshuab thiab hnav.
Cov khoom siv ua los ntawm SiC huv si nyuaj rau ua kom ntom tsis muaj cov khoom ntxiv, xav tau kev sintering siab heev. Nadeau et al. tau npaj tiav SiC uas ntom tag nrho yam tsis muaj cov khoom ntxiv ntawm 2500 ° C thiab 5000 MPa; Sun et al. tau txais cov khoom siv β-SiC nrog Vickers hardness txog li 41.5 GPa ntawm 25 GPa thiab 1400 ° C. Siv 4 GPa siab, SiC ceramics nrog cov ntom txheeb ze ntawm kwv yees li 98% thiab 99%, qhov nyuaj ntawm 35 GPa, thiab elastic modulus ntawm 450 GPa tau npaj ntawm 1500 ° C thiab 1900 ° C, raws li. Sintering micron-sized SiC hmoov ntawm 5 GPa thiab 1500 ° C tau txais cov khoom siv ua los ntawm ceramics nrog qhov nyuaj ntawm 31.3 GPa thiab qhov ntom txheeb ze ntawm 98.4%.
Txawm hais tias cov txiaj ntsig no qhia tau tias qhov siab heev tuaj yeem ua tiav qhov kev sib xyaw ua ke yam tsis muaj cov khoom ntxiv, qhov nyuaj thiab tus nqi siab ntawm cov khoom siv xav tau txwv tsis pub siv rau hauv kev lag luam. Yog li ntawd, hauv kev npaj ua haujlwm, cov khoom ntxiv me me lossis cov hmoov granulation feem ntau siv los txhim kho lub zog tsav tsheb sintering.
Los ntawm kev ntxiv 4 wt.% phenolic resin ua ib qho khoom ntxiv thiab sintering ntawm 2350 ° C thiab 50 MPa, SiC ceramics nrog tus nqi densification ntawm 92% thiab purity ntawm 99.998% tau txais. Siv cov khoom ntxiv tsawg (boric acid thiab D-fructose) thiab sintering ntawm 2050 ° C thiab 40 MPa, high-purity SiC nrog qhov sib piv ceev > 99.5% thiab cov ntsiab lus B seem ntawm tsuas yog 556 ppm tau npaj. Cov duab SEM qhia tau hais tias, piv rau cov qauv sintered tsis muaj siab, cov qauv kub-nias muaj cov noob me me, tsawg dua qhov hws, thiab qhov ceev dua. Lub zog flexural yog 453.7 ± 44.9 MPa, thiab cov modulus elastic ncav cuag 444.3 ± 1.1 GPa.
Los ntawm kev ncua lub sijhawm tuav ntawm 1900 ° C, qhov loj ntawm cov noob tau nce ntxiv los ntawm 1.5 μm mus rau 1.8 μm, thiab kev ua kom sov tau zoo dua los ntawm 155 mus rau 167 W · m⁻¹ · K⁻¹, thaum tseem txhim kho kev tiv thaiv xeb ntawm plasma.
Nyob rau hauv cov xwm txheej ntawm 1850 ° C thiab 30 MPa, kub nias thiab kub nias sai ntawm granulated thiab annealed SiC hmoov tau ua rau β-SiC ceramics ntom ntom tag nrho yam tsis muaj cov khoom ntxiv, nrog rau qhov ceev ntawm 3.2 g / cm³ thiab qhov kub sintering 150–200 ° C qis dua cov txheej txheem ib txwm muaj. Cov ceramics tau pom qhov nyuaj ntawm 2729 GPa, tawg toughness ntawm 5.25–5.30 MPa·m ^ 1/2, thiab zoo heev creep tsis kam (creep nqi ntawm 9.9 × 10⁻¹⁰ s⁻¹ thiab 3.8 × 10⁻⁹ s⁻¹ ntawm 1400 ° C / 1450 ° C thiab 100 MPa).
(A) Duab SEM ntawm qhov chaw ci ntsa iab; (B) Duab SEM ntawm qhov chaw tawg; (C, D) Duab BSD ntawm qhov chaw ci ntsa iab
Hauv kev tshawb fawb txog kev luam ntawv 3D rau cov khoom siv piezoelectric, cov khoom siv ceramic slurry, ua lub hauv paus tseem ceeb uas cuam tshuam rau kev tsim thiab kev ua tau zoo, tau dhau los ua qhov tseem ceeb hauv tebchaws thiab thoob ntiaj teb. Cov kev tshawb fawb tam sim no feem ntau qhia tau tias cov yam ntxwv xws li qhov loj me ntawm cov hmoov me me, cov khoom siv slurry viscosity, thiab cov khoom khov kho cuam tshuam rau qhov zoo ntawm kev tsim thiab cov khoom piezoelectric ntawm cov khoom kawg.
Kev tshawb fawb tau pom tias cov hmoov av nplaum uas tau npaj siv cov hmoov av nplaum me me, submicron, thiab nano muaj qhov sib txawv tseem ceeb hauv cov txheej txheem stereolithography (piv txwv li, LCD-SLA). Thaum cov khoom me me txo qis, cov viscosity ntawm cov hmoov av nplaum nce ntxiv, nrog rau cov hmoov av nplaum me me uas tsim cov slurries nrog viscosities ncav cuag billions ntawm mPa·s. Cov hmoov av nplaum uas muaj cov hmoov av nplaum me me feem ntau yuav tawg thiab tev tawm thaum luam ntawv, thaum cov hmoov av nplaum me me thiab nano muaj cov cwj pwm tsim khoom ruaj khov dua. Tom qab sintering kub siab, cov qauv ceramic tau txais qhov ceev ntawm 5.44 g / cm³, tus lej piezoelectric (d₃₃) ntawm kwv yees li 200 pC / N, thiab cov yam ntxwv poob qis, qhia txog cov khoom teb electromechanical zoo heev.
Tsis tas li ntawd xwb, hauv cov txheej txheem micro-stereolithography, kev kho cov khoom khov ntawm PZT-hom slurries (piv txwv li, 75 wt.%) tau ua rau cov khoom sintered nrog qhov ceev ntawm 7.35 g / cm³, ua tiav qhov piezoelectric tas mus li ntawm 600 pC / N nyob rau hauv poling hluav taws xob teb. Kev tshawb fawb ntawm micro-scale deformation compensation tau txhim kho qhov tseeb ntawm kev tsim, txhim kho qhov tseeb geometric los ntawm txog li 80%.
Lwm txoj kev tshawb fawb txog PMN-PT piezoelectric ceramics tau qhia tias cov khoom khov muaj feem cuam tshuam rau cov qauv ceramic thiab cov khoom siv hluav taws xob. Thaum muaj 80 wt.% cov khoom khov, cov khoom seem tau yooj yim tshwm sim hauv cov ceramics; thaum cov khoom khov nce mus txog 82 wt.% thiab siab dua, cov khoom seem maj mam ploj mus, thiab cov qauv ceramic tau ua kom huv dua, nrog rau kev ua tau zoo dua. Thaum muaj 82 wt.%, cov ceramics tau pom cov khoom siv hluav taws xob zoo tshaj plaws: piezoelectric tas mus li ntawm 730 pC/N, permittivity ntawm 7226, thiab dielectric poob ntawm tsuas yog 0.07.
Hauv kev xaus, qhov loj me ntawm cov khoom me me, cov ntsiab lus khoom khov, thiab cov khoom rheological ntawm cov khoom siv ceramic slurries tsis yog tsuas yog cuam tshuam rau qhov ruaj khov thiab qhov tseeb ntawm cov txheej txheem luam ntawv xwb tab sis kuj txiav txim siab ncaj qha rau qhov ceev thiab piezoelectric teb ntawm cov cev sintered, ua rau lawv yog cov yam ntxwv tseem ceeb rau kev ua tiav cov khoom siv 3D-luam tawm piezoelectric ceramics.
Cov txheej txheem tseem ceeb ntawm LCD-SLA 3D luam ntawv ntawm BT / UV qauv
Cov khoom ntawm PMN-PT ceramics nrog cov khoom sib txawv
IV. Spark Plasma Sintering
Kev siv tshuab sintering plasma sintering (SPS) yog ib txoj kev siv tshuab sintering uas siv cov hluav taws xob pulsed thiab lub zog mechanical tib lub sijhawm siv rau cov hmoov kom ua tiav qhov ceev ceev. Hauv cov txheej txheem no, hluav taws xob ncaj qha ua rau pwm thiab hmoov sov, tsim Joule cua sov thiab plasma, ua rau sintering zoo hauv lub sijhawm luv luv (feem ntau hauv 10 feeb). Kev ua kom sov sai txhawb kev sib kis ntawm qhov chaw, thaum lub zog spark pab tshem tawm cov pa roj adsorbed thiab cov txheej oxide ntawm cov hmoov, txhim kho kev ua haujlwm sintering. Cov nyhuv electromigration uas tshwm sim los ntawm cov teb electromagnetic kuj ua rau atomic diffusion zoo dua.
Piv rau kev nias kub ib txwm muaj, SPS siv cua sov ncaj qha dua, ua rau muaj kev sib sau ua ke ntawm qhov kub qis dua thaum tseem tiv thaiv kev loj hlob ntawm cov noob kom tau txais cov qauv me me thiab sib xws. Piv txwv li:
- Tsis muaj cov khoom ntxiv, siv cov hmoov SiC av ua cov khoom siv raw, sintering ntawm 2100 ° C thiab 70 MPa rau 30 feeb tau txais cov qauv nrog 98% qhov ceev sib piv.
- Sintering ntawm 1700 ° C thiab 40 MPa rau 10 feeb tsim tau cubic SiC nrog 98% ceev thiab cov noob loj tsuas yog 30–50 nm.
- Siv 80 µm granular SiC hmoov thiab sintering ntawm 1860°C thiab 50 MPa rau 5 feeb ua rau muaj kev ua tau zoo SiC ceramics nrog 98.5% qhov ceev sib piv, Vickers microhardness ntawm 28.5 GPa, flexural zog ntawm 395 MPa, thiab fracture toughness ntawm 4.5 MPa·m^1/2.
Kev tshuaj xyuas microstructural qhia tau hais tias thaum qhov kub sintering nce ntxiv ntawm 1600 ° C mus rau 1860 ° C, cov khoom porosity txo qis heev, mus txog qhov ceev tag nrho ntawm qhov kub siab.
Cov qauv me me ntawm SiC ceramics sintered ntawm qhov kub sib txawv: (A) 1600 ° C, (B) 1700 ° C, (C) 1790 ° C thiab (D) 1860 ° C
V. Kev Tsim Khoom Ntxiv
Kev tsim khoom ntxiv (AM) tsis ntev los no tau ua pov thawj tias muaj peev xwm loj heev hauv kev tsim cov khoom siv ceramic nyuaj vim nws cov txheej txheem tsim kho txheej. Rau SiC ceramics, ntau yam thev naus laus zis AM tau tsim, suav nrog binder jetting (BJ), 3DP, selective laser sintering (SLS), direct ink writing (DIW), thiab stereolithography (SL, DLP). Txawm li cas los xij, 3DP thiab DIW muaj qhov tseeb qis dua, thaum SLS feem ntau ua rau muaj kev ntxhov siab thermal thiab tawg. Qhov sib piv, BJ thiab SL muab cov txiaj ntsig zoo dua hauv kev tsim cov khoom siv ceramics uas muaj kev ntshiab siab, muaj qhov tseeb siab.
- Kev Siv Cov Ntawv Binder Jetting (BJ)
Cov thev naus laus zis BJ suav nrog kev txau cov binder rau cov hmoov sib txuas ua ke, ua raws li kev tshem tawm thiab sintering kom tau txais cov khoom siv ceramic kawg. Kev sib xyaw BJ nrog cov pa tshuaj lom neeg (CVI), cov khoom siv SiC uas muaj kev ntshiab siab, tag nrho crystalline tau npaj tiav. Cov txheej txheem suav nrog:
① Tsim cov SiC ceramic ntsuab lub cev siv BJ.
② Ua kom ntom ntawm CVI ntawm 1000 ° C thiab 200 Torr.
③ Cov khoom siv SiC kawg muaj qhov ceev ntawm 2.95 g / cm³, thermal conductivity ntawm 37 W / m · K, thiab flexural zog ntawm 297 MPa.
Daim duab kos ntawm kev luam ntawv nplaum (BJ). (A) Qauv tsim los ntawm lub khoos phis tawj (CAD), (B) daim duab kos ntawm lub hauv paus ntsiab lus ntawm BJ, (C) kev luam ntawv ntawm SiC los ntawm BJ, (D) kev sib sau ua ke ntawm SiC los ntawm cov pa tshuaj lom neeg (CVI)
- Kev Siv Tshuab Kos Duab (SL)
SL yog ib txoj kev siv tshuab ua cov khoom siv ceramic uas siv UV-curing nrog kev ua haujlwm siab heev thiab muaj peev xwm tsim cov qauv nyuaj. Txoj kev no siv cov khoom siv ceramic uas muaj cov khoom khov kho thiab viscosity tsawg los tsim cov khoom siv ceramic ntsuab 3D los ntawm kev ua photopolymerization, ua raws li kev debinding thiab sintering kub kom tau txais cov khoom kawg.
Siv cov kua SiC 35 vol.%, cov khoom zoo 3D ntsuab tau npaj nyob rau hauv 405 nm UV irradiation thiab ntxiv densified ntawm polymer burnout ntawm 800 ° C thiab PIP kev kho mob. Cov txiaj ntsig tau qhia tias cov qauv npaj nrog 35 vol.% slurry tau ua tiav qhov ceev ntawm 84.8%, ua tau zoo dua 30% thiab 40% pawg tswj.
Los ntawm kev qhia txog lipophilic SiO₂ thiab phenolic epoxy resin (PEA) los hloov cov slurry, kev ua tau zoo ntawm photopolymerization tau zoo dua. Tom qab sintering ntawm 1600 ° C rau 4 teev, kev hloov pauv ze li ntawm tag nrho mus rau SiC tau ua tiav, nrog cov pa oxygen kawg ntawm tsuas yog 0.12%, ua rau ib kauj ruam tsim cov khoom siv SiC uas muaj kev ntshiab siab, cov qauv nyuaj yam tsis muaj cov kauj ruam ua ntej oxidation lossis ua ntej infiltration.
Daim duab qhia txog cov qauv luam ntawv thiab nws cov txheej txheem sintering. Cov tsos ntawm cov qauv tom qab ziab ntawm (A) 25 ° C, pyrolysis ntawm (B) 1000 ° C, thiab sintering ntawm (C) 1600 ° C.
Los ntawm kev tsim cov khoom siv Si₃N₄ uas muaj teeb pom kev zoo rau kev luam ntawv 3D stereolithography thiab siv cov txheej txheem debinding-presintering thiab kev laus kub siab, Si₃N₄ ceramics nrog 93.3% theoretical density, tensile zog ntawm 279.8 MPa, thiab flexural zog ntawm 308.5–333.2 MPa tau npaj. Cov kev tshawb fawb pom tias nyob rau hauv cov xwm txheej ntawm 45 vol.% cov ntsiab lus khoom thiab 10 s lub sijhawm raug, ib txheej ntsuab lub cev nrog IT77-qib kev kho qhov tseeb tuaj yeem tau txais. Cov txheej txheem debinding kub qis nrog tus nqi cua sov ntawm 0.1 ° C / feeb tau pab tsim cov lub cev ntsuab tsis muaj tawg.
Kev sintering yog ib kauj ruam tseem ceeb uas cuam tshuam rau kev ua tau zoo kawg hauv stereolithography. Kev tshawb fawb qhia tau tias kev ntxiv cov khoom pab sintering tuaj yeem txhim kho qhov ceev ntawm cov khoom siv ceramic thiab cov khoom siv kho tshuab. Siv CeO₂ ua ib qho khoom pab sintering thiab cov thev naus laus zis sintering pab hluav taws xob los npaj cov khoom siv Si₃N₄ ceramics uas muaj qhov ceev siab, CeO₂ tau pom tias sib cais ntawm cov ciam teb ntawm cov noob, txhawb kev swb thiab kev sib sau ua ke ntawm cov noob. Cov khoom siv ceramics tau pom Vickers hardness ntawm HV10/10 (1347.9 ± 2.4) thiab kev tawg ntawm (6.57 ± 0.07) MPa·m¹/². Nrog MgO-Y₂O₃ ua cov khoom ntxiv, cov khoom siv ceramic microstructure homogeneity tau txhim kho, ua rau muaj kev ua tau zoo dua. Ntawm qib doping tag nrho ntawm 8 wt.%, lub zog flexural thiab thermal conductivity ncav cuag 915.54 MPa thiab 59.58 W·m⁻¹·K⁻¹, raws li.
VI. Xaus Lus
Hauv kev xaus lus, cov khoom siv ceramic silicon carbide (SiC) uas muaj cov khoom siv ceramic zoo heev, tau ua pov thawj tias muaj kev siv dav hauv semiconductors, aerospace, thiab cov khoom siv uas muaj xwm txheej ceev. Daim ntawv no tau tshuaj xyuas tsib txoj kev npaj rau cov khoom siv ceramic SiC uas muaj cov khoom siv ceramic zoo - recrystallization sintering, pressureless sintering, hot pressing, spark plasma sintering, thiab additive manufacturing - nrog rau kev sib tham ntxaws ntxaws txog lawv cov txheej txheem densification, cov txheej txheem tseem ceeb, kev ua haujlwm ntawm cov khoom siv, thiab cov txiaj ntsig thiab kev txwv.
Nws pom tseeb tias cov txheej txheem sib txawv txhua tus muaj cov yam ntxwv tshwj xeeb hauv kev ua tiav qhov huv siab, qhov ceev ceev, cov qauv nyuaj, thiab kev ua tau hauv kev lag luam. Cov thev naus laus zis tsim khoom ntxiv, tshwj xeeb, tau qhia txog lub peev xwm muaj zog hauv kev tsim cov khoom sib xyaw thiab cov khoom sib txawv, nrog rau kev tawg ua ntu zus hauv cov teb xws li stereolithography thiab binder jetting, ua rau nws yog qhov kev taw qhia tseem ceeb rau kev npaj SiC ceramic siab-purity.
Kev tshawb fawb yav tom ntej txog kev npaj SiC ceramic uas muaj kev ntshiab siab yuav tsum tau tshawb nrhiav tob dua, txhawb kev hloov pauv ntawm qhov chaw kuaj mob mus rau qhov loj, kev siv engineering uas ntseeg tau heev, yog li muab kev txhawb nqa cov khoom siv tseem ceeb rau kev tsim khoom siv siab thiab cov thev naus laus zis tshiab.
XKH yog ib lub tuam txhab ua lag luam siab heev uas tshwj xeeb hauv kev tshawb fawb thiab kev tsim cov khoom siv ceramic ua tau zoo. Nws mob siab rau kev muab cov kev daws teeb meem rau cov neeg siv khoom hauv daim ntawv ntawm cov khoom siv silicon carbide (SiC) uas muaj kev ntshiab siab. Lub tuam txhab muaj cov thev naus laus zis npaj cov khoom siv siab heev thiab muaj peev xwm ua tiav qhov tseeb. Nws txoj kev lag luam suav nrog kev tshawb fawb, kev tsim khoom, kev ua tiav qhov tseeb, thiab kev kho qhov chaw ntawm cov khoom siv SiC uas muaj kev ntshiab siab, ua tau raws li cov kev cai nruj ntawm semiconductor, lub zog tshiab, aerospace thiab lwm yam teb rau cov khoom siv ceramic ua tau zoo. Siv cov txheej txheem sintering laus thiab cov thev naus laus zis tsim khoom ntxiv, peb tuaj yeem muab cov neeg siv khoom ib qho kev pabcuam ib zaug xwb los ntawm kev ua kom zoo dua cov mis ntawm cov khoom siv, kev tsim cov qauv nyuaj mus rau kev ua tiav qhov tseeb, kom ntseeg tau tias cov khoom muaj cov khoom siv kho tshuab zoo heev, kev ruaj khov thermal thiab kev tiv thaiv corrosion.
Lub sijhawm tshaj tawm: Lub Xya Hli-30-2025