Chemical Composition ntawm Alumina Ceramic
Cov khoom tseem ceeb ntawm alumina ceramics yog aluminium oxide (Al2O3), uas yog cov tshuaj sib xyaw ua ke ntawm ob lub txhuas (Al) atoms sib txuas rau peb cov pa oxygen (O) atoms. Nws yog cov khoom siv crystalline nrog lub hexagonal kaw-packed qauv, qhov twg txhuas cations nyob ib puag ncig los ntawm oxygen anions nyob rau hauv ib tug densely packed txheej txheem.
Ntxiv nrog rau txhuas oxide, alumina ceramics tuaj yeem muaj cov kab ntawm impurities nyob ntawm cov txheej txheem tsim khoom tshwj xeeb thiab cov khoom siv raw. Cov impurities no tuaj yeem suav nrog silica (SiO2), ferric oxide (Fe2O3), titania (TiO2), thiab ntau yam oxides. Lub xub ntiag ntawm impurities tuaj yeem cuam tshuam cov khoom siv, xws li xim, hluav taws xob conductivity, thiab thermal expansion.
Kev tsim khoom
1. Kev npaj cov khoom nyoos
Cov khoom siv tseem ceeb yog high-purity aluminium oxide, muab los ntawm bauxite ore los ntawm cov txheej txheem refining. Cov txheej txheem no suav nrog kev sib tsoo, sib tsoo, thiab ntxuav cov khoom siv kom tau txais cov hmoov zoo ntawm txhuas oxide.
2. Kev tsim
Cov hmoov alumina npaj tau sib xyaw nrog cov ntawv khi (xws li cov organic polymers lossis dej) los tsim cov khoom loj. Qhov sib tov no tuaj yeem ua rau ntau hom kev siv cov txheej txheem xws li nias, extrusion, lossis plam casting.
3. Sintering
Cov duab tsim tau raug rau cov txheej txheem hluav taws kub kub hu ua sintering. Cov txheej txheem no suav nrog cov cua sov ntawm cov khoom siv ceramic nyob rau hauv qhov chaw tswj kom sov siab tshaj 1650 degree. Thaum lub sij hawm sintering, cov alumina hais fuse ua ke, uas ua rau ib tug ntom, khoom ceramic qauv.
4. Machining (yeem)
Tom qab sintering, cov khoom siv ceramic tuaj yeem dhau los ua cov txheej txheem xws li kev sib tsoo, milling, lossis polishing kom ua tiav qhov ntev thiab qhov chaw tiav.
5. Kev ua tiav kawg
Nyob ntawm daim ntawv thov, cov kauj ruam ntxiv xws li glazing, txheej, lossis metallizing yuav raug ua haujlwm los txhim kho cov khoom tshwj xeeb.
Hom Alumina Ceramics
Alumina ceramics tuaj yeem muab faib ua ntau pawg raws li lawv cov muaj pes tsawg leeg thiab cov khoom:
1. High-Purity Alumina (HPA)
HPA yog tsim los ntawm 90% lossis siab dua ntshiab txhuas oxide. Nws muaj cov khoom siv hluav taws xob zoo heev, thermal conductivity, thiab tshwj xeeb hnav tsis kam. HPA yog siv nyob rau hauv daim ntawv thov xws li semiconductor manufacturing, high-temperature crucibles, thiab hluav taws xob insulators.
2. Ib nrab Stabilized Zirconia Toughened Alumina (PSZTA)
Cov khoom sib xyaw no ua ke nrog alumina nrog ib feem me me ntawm zirconia (ZrO2). Cov zirconia particles txhim khu cov pob txha toughness thiab lub zog ntawm cov ceramic. PSZTA feem ntau yog siv rau hauv daim ntawv thov uas yuav tsum tau muaj kev cuam tshuam zoo thiab hnav kev ua haujlwm, xws li cov cuab yeej txiav thiab cov khoom siv coj los siv.
Cov khoom ntawm Alumina Ceramics
Alumina ceramics muaj npe nrov rau lawv cov khoom zoo kawg li, uas ua rau lawv xav tau ntau hauv kev lag luam:
1. Mechanical Strength
Alumina ceramics nthuav tawm siab compressive thiab flexural lub zog, ua rau lawv muaj peev xwm tiv taus txhua yam khoom thauj thiab cuam tshuam.
2. Hardness
Lawv yog cov ntaub ntawv nyuaj heev, qeb qis dua pob zeb diamond ntawm Mohs nplai ntawm hardness. Cov cuab yeej no pub rau lawv zoo heev hnav tsis kam.
3. Thermal stability
Alumina ceramics tuaj yeem tiv taus qhov kub thiab txias, ua rau lawv haum rau kev siv hauv qhov chaw kub kub.
4. Hluav taws xob rwb thaiv tsev
Lawv muaj cov khoom siv hluav taws xob zoo heev, ua rau lawv tseem ceeb hauv kev siv hluav taws xob thiab semiconductor.
5. Tshuaj Inertness
Alumina ceramics tiv taus ntau yam tshuaj, acids, thiab cov hauv paus, ua rau lawv haum rau siv nyob rau hauv ib puag ncig corrosive.
6. Biocompatibility
Hauv qee cov ntaub ntawv, alumina ceramics yog biocompatible thiab tuaj yeem siv rau hauv kev kho mob cog thiab prosthetics.
Hauv kev xaus, alumina ceramics yog cov chav kawm ntau yam ntawm cov ntaub ntawv siab heev nrog ib qho tshwj xeeb muaj pes tsawg leeg feem ntau suav nrog aluminium oxide. Lawv cov khoom tshwj xeeb, suav nrog lub zog txhua yam, hardness, thermal stability, hluav taws xob rwb thaiv tsev, thiab tshuaj inertness, ua rau lawv invaluable nyob rau hauv ib tug ntau yam ntawm industrial daim ntaub ntawv. Nkag siab txog qhov muaj pes tsawg leeg thiab cov txheej txheem tsim khoom ntawm alumina ceramics yog qhov tseem ceeb rau kev siv lawv cov peev txheej hauv ntau yam lag luam thiab thev naus laus zis.
