Dab tsi yog cov khoom siv mullite?
Cov khoom siv ceramic
Mullite los yog porcelainite yog ib qho tsis tshua muaj silicate ntxhia tsim thaum sib cuag metamorphism ntawm av nplaum ntxhia. Nws tuaj yeem tsim ob daim ntawv stoichiometric: 3Al2O32 TSI2lub 2 al2O3SiO2. Qhov txawv txav, mullite tsis muaj nqi sib npaug cations tam sim no. Raws li qhov tshwm sim, muaj peb qhov sib txawv txhuas qhov chaw: ob qhov sib txawv tetrahedral thiab ib qho octahedral.
Mullite (porcelainite) tuaj yeem pom raws li cov khoom siv hauv cov pob zeb thermally-metamorphosed hu ua porcellanite.
Porcelain Applications
Mullite muaj nyob rau hauv daim ntawv ntawm koob nyob rau hauv porcelain. Nws yog tsim nyob rau hauv ntau yam melting thiab firing txheej txheem, thiab yog siv raws li ib tug refractory khoom, vim nws siab melting point ntawm 1,840 degree.
Mullite morphology yog qhov tseem ceeb rau nws daim ntawv thov. Nyob rau hauv cov ntaub ntawv no, muaj ob hom morphologies rau mullite. Ib qho yog cov duab platelet nrog qhov sib piv qis thiab qhov thib ob yog rab koob zoo nrog qhov sib piv siab. Yog tias rab koob zoo li mullite tuaj yeem tsim hauv lub cev ceramic thaum lub sijhawm sintering, nws muaj kev cuam tshuam rau ob qho tib si txhua yam thiab lub cev los ntawm kev ua kom lub zog thiab thermal poob siab. Cov xwm txheej tseem ceeb tshaj plaws yog cuam tshuam nrog cov tshuaj ceramics. Yog tias qhov sib piv ntawm silica thiab alumina nrog cov khoom siv qis xws li sodium thiab calcium tau hloov kho, lub koob zoo li mullite cov ntaub ntawv ntawm li 1,400 degree thiab cov koob yuav cuam tshuam. Qhov no mechanical interlocking contributes rau siab mechanical zog ntawm porcelain.
