Fused Silica yog ib qho khoom siv zoo heev rau kev siv peev casting, refractories, foundries, technical ceramics, thiab lwm yam kev siv uas yuav tsum tau ib tug zoo ib yam, siab purity khoom nrog tsawg thermal expansion.
Tshuaj muaj pes tsawg leeg | Qib thib ib | Hom | Qib thib ob | Hom |
SiO 2 | 99.9% min | 99.92 ib | 99.8% min | 99.84 ib |
Fe2O 3 | 50 ppm max | 19 | 80 ppm max | 50 |
Al2O3 | 100 ppm max | 90 | 150 ppm max | 120 |
K2O | 30 ppm max | 23 | 30 ppm max | 25 |
Fused Silica yog tsim los ntawm siab purity silica, siv cov cuab yeej fusion tshwj xeeb los xyuas kom meej qhov zoo tshaj plaws. Peb cov Fused Silica yog tshaj 99% amorphous thiab muaj qhov sib npaug qis heev ntawm thermal expansion thiab siab tiv thaiv thermal shock. Fused Silica yog inert, muaj tshuaj lom neeg ruaj khov, thiab muaj hluav taws xob tsis tshua muaj hluav taws xob.
Fused quartz muaj cov khoom siv thermal thiab tshuaj lom neeg zoo li cov khoom siv rau kev loj hlob ib leeg los ntawm cov yaj, thiab nws cov purity siab thiab tus nqi qis ua rau nws tshwj xeeb tshaj yog rau kev loj hlob ntawm high-purity crystals. txheej ntawm pyrolytic carbon txheej yog xav tau ntawm cov yaj thiab quartz crucible.
Fused silica muaj ntau yam zoo kawg nkaus uas hais txog nws cov khoom siv tshuab, thermal, tshuaj thiab kho qhov muag:
• Nws yog ib qho nyuaj thiab muaj zog, thiab tsis nyuaj rau tshuab thiab polish. (Ib tug kuj tseem siv laser micromachining.)
• Lub iav hloov pauv kub ua rau nws yooj yim dua rau yaj dua li lwm cov iav kho qhov muag, tab sis nws kuj txhais tau tias qhov kub ua haujlwm kuj tseem ua tau. Txawm li cas los xij, fused silica tuaj yeem nthuav tawm devitrification (lub zos crystallization nyob rau hauv daim ntawv ntawm cristobalite) saum toj 1100 ° C, tshwj xeeb tshaj yog nyob rau hauv kev cuam tshuam ntawm tej yam kab mob impurities, thiab qhov no yuav lwj lub kho qhov muag khoom.
• Cov thermal expansion coefficient tsawg heev - txog 0.5 · 10−6 K−1. Qhov no yog ob peb zaug qis dua rau cov tsom iav. Txawm tias tsis muaj zog thermal expansion nyob ib ncig ntawm 10-8 K-1 yog ua tau nrog ib daim ntawv hloov ntawm fused silica nrog ib co titanium dioxide, qhia los ntawm Corning [4] thiab hu ua ultra low expansion iav.
• Lub siab thermal shock tsis kam yog los ntawm qhov tsis muaj zog thermal expansion; tsuas muaj kev ntxhov siab me ntsis txawm tias thaum kub kub gradients tshwm sim vim txias txias.
• Silica tuaj yeem ua tshuaj dawb huv, nyob ntawm txoj kev tsim khoom (saib hauv qab).
• Silica yog tshuaj lom neeg heev, tshwj tsis yog hydrofluoric acid thiab alkaline daws. Ntawm qhov kub siab, nws kuj yog me ntsis soluble hauv dej (ntau tshaj li crystalline quartz).
• Lub cheeb tsam pob tshab yog qhov dav heev (txog 0.18 μm mus rau 3 μm), tso cai rau kev siv cov fused silica tsis tsuas yog nyob rau hauv tag nrho cov pom spectral cheeb tsam, tab sis kuj nyob rau hauv lub ultraviolet thiab infrared. Txawm li cas los xij, cov kev txwv tseem ceeb nyob ntawm cov khoom zoo. Piv txwv li, muaj zog infrared absorption bands tuaj yeem tshwm sim los ntawm OH cov ntsiab lus, thiab UV nqus los ntawm cov hlau tsis huv (saib hauv qab).
• Raws li cov khoom siv amorphous, fused silica yog optically isotropic - sib piv rau crystalline quartz. Qhov no txhais tau hais tias nws tsis muaj birefringence, thiab nws qhov refractive index (saib daim duab 1) tuaj yeem ua tus cwj pwm nrog ib tus qauv Sellmeier.