Qee qhov kev lag luam pov tseg tau pom tias muaj txiaj ntsig zoo hauv kev tsim cov mullite ceramics. Cov khoom siv khib nyiab no yog nplua nuj nyob hauv qee cov hlau oxides xws li silica (SiO2) thiab alumina (Al2O3). Qhov no muab pov tseg lub peev xwm los siv los ua cov khoom pib rau kev npaj mullite ceramics. Lub hom phiaj ntawm daim ntawv tshuaj xyuas no yog los sau thiab tshuaj xyuas ntau yam kev npaj cov mullite ceramics uas siv ntau yam kev lag luam pov tseg ua cov khoom pib. Qhov kev tshuaj xyuas no kuj piav qhia txog qhov kub thiab txias sintering thiab tshuaj additives siv nyob rau hauv kev npaj thiab nws cov teebmeem. Kev sib piv ntawm ob qho tib si lub zog thiab thermal expansion ntawm cov ntaub ntawv qhia mullite ceramics npaj los ntawm ntau yam kev lag luam pov tseg kuj tau hais hauv txoj haujlwm no.
Mullite, feem ntau txhais tau tias yog 3Al2O3∙2SiO2, yog cov khoom siv ceramic zoo heev vim nws lub cev tsis zoo. Nws muaj qhov siab melting point, qis coefficient ntawm thermal expansion, siab zog ntawm high-temperature, thiab muaj ob qho tib si thermal shock thiab creep resistance [1]. Cov khoom siv hluav taws xob zoo tshaj plaws thiab cov khoom siv kho tshuab no ua rau cov khoom siv tau siv rau hauv cov ntawv thov xws li cov khoom siv hluav taws xob, cov rooj tog zaum hauv tsev, cov khoom siv hluav taws xob rau cov khoom siv hluav taws xob, cov tub rau hluav taws xob, thiab cov khoom siv hluav taws xob.
Mullite tuaj yeem pom tsuas yog cov ntxhia tsis txaus ntawm Mull Island, Scotland [2]. Vim nws tsis tshua muaj nyob hauv qhov xwm txheej, tag nrho cov mullite ceramics siv hauv kev lag luam yog tib neeg tsim. Ntau qhov kev tshawb fawb tau ua tiav los npaj mullite ceramics siv cov khoom sib txawv, pib los ntawm kev lag luam / kuaj qib tshuaj [3] lossis ib txwm muaj aluminosilicate minerals [4]. Txawm li cas los xij, tus nqi ntawm cov khoom pib no yog kim, uas yog synthesized los yog mined ua ntej. Tau ntau xyoo, cov kws tshawb fawb tau nrhiav kev lag luam lwm txoj hauv kev los tsim cov mullite ceramics. Yog li ntawd, ntau yam mullite precursors muab tau los ntawm industrial khib nyiab tau raug tshaj tawm nyob rau hauv cov ntaub ntawv. Cov khoom pov tseg no muaj cov ntsiab lus tseem ceeb ntawm silica thiab alumina, uas yog cov tshuaj tseem ceeb uas yuav tsum tau ua los tsim cov mullite ceramics. Lwm cov txiaj ntsig ntawm kev siv cov khoom siv pov tseg no yog lub zog thiab kev txuag nqi yog tias cov khib nyiab tau hloov pauv thiab rov siv dua ua cov khoom siv engineering. Tsis tas li ntawd, qhov no tseem tuaj yeem pab txo qis ib puag ncig lub nra thiab txhim kho nws cov txiaj ntsig kev lag luam.
Txhawm rau tshawb xyuas seb cov khoom siv hluav taws xob ntshiab huv puas tuaj yeem siv los ua cov khoom siv mullite ceramics, cov khoom siv hluav taws xob dawb huv sib xyaw nrog cov hmoov alumina thiab cov khoom siv hluav taws xob ntshiab huv raws li cov khoom siv raw tau muab piv. Cov khoom ntawm mullite ceramic tau tshawb xyuas. XRD thiab SEM tau siv los kawm txog theem muaj pes tsawg leeg thiab microstructure.
Cov txiaj ntsig tau pom tias cov ntsiab lus ntawm mullite yog nce nrog nce sintering kub, thiab nyob rau tib lub sij hawm lub bulk ntom yog escalated. Cov khoom siv raw yog cov khoom siv hluav taws xob ntshiab huv, yog li cov haujlwm sintering ntau dua, thiab cov txheej txheem sintering tuaj yeem nrawm dua, thiab qhov ceev kuj tseem nce ntxiv. Thaum lub mullite tau npaj nkaus xwb los ntawm Electroceramics nkim thiab compressive lub zog yog me tshaj, thiab cov khoom siv lub cev me me yuav yog qhov zoo tshaj plaws
Tsav los ntawm kev xav tau ntawm cov nqi qis thiab ib puag ncig zoo rau lwm txoj hauv kev, ntau qhov kev tshawb fawb tau siv ntau yam kev lag luam pov tseg raws li cov khoom pib los tsim cov mullite ceramics. Cov txheej txheem ua, sintering kub, thiab tshuaj additives tau raug tshuaj xyuas. Cov txheej txheem kev ua haujlwm ib txwm muaj uas koom nrog kev sib xyaw, nias, thiab cov tshuaj tiv thaiv sintering ntawm mullite precursor yog txoj kev siv ntau tshaj plaws vim nws qhov yooj yim thiab siv tau zoo. Txawm hais tias txoj kev no muaj peev xwm tsim cov porous mullite ceramics, qhov pom tseeb ntawm qhov tshwm sim ntawm mullite ceramics tau tshaj tawm kom nyob qis dua 50%. Ntawm qhov tod tes, khov casting tau pom tias muaj peev xwm tsim tau cov porous mullite ceramic, nrog qhov pom meej porosity ntawm 67%, txawm tias nyob rau ntawm qhov kub siab heev ntawm 1500 ° C. Kev tshuaj xyuas ntawm qhov kub thiab txias sintering thiab sib txawv tshuaj additives siv nyob rau hauv zus tau tej cov mullite yog nqa tawm. Nws yog ntshaw kom siv ib tug sintering kub siab tshaj 1500 ° C rau mullite ntau lawm, vim hais tias cov tshuaj tiv thaiv ntau dua ntawm Al2O3 thiab SiO2 nyob rau hauv lub precursor. Txawm li cas los xij, cov ntsiab lus silica ntau dhau cuam tshuam nrog impurities hauv cov khoom ua ntej tuaj yeem ua rau tus qauv deformation lossis meltdown thaum kub kub sintering. Raws li rau cov tshuaj additives, CaF2, H3BO3, Na2SO4, TiO2, AlF3, thiab MoO3 tau raug tshaj tawm tias yog ib qho kev pab kom txo qis sintering kub thaum V2O5, Y2O3-doped ZrO2 thiab 3Y-PSZ yuav siv tau los txhawb densification rau mullite ceramics. Doping nrog tshuaj ntxiv xws li AlF3, Na2SO4, NaH2PO4·2H2O, V2O5, thiab MgO pab anisotropic kev loj hlob ntawm mullite whiskers, uas tom qab txhim kho lub cev lub zog thiab toughness ntawm mullite ceramics.
Post lub sij hawm: Aug-29-2023