Cov Kev Siv Seev Txheej yog siv dav hauv ntau qhov kev lag luam. Tsis-oxide ceramics nyob rau qhov feem ntau ntawm cov kev ua haujlwm ceramics. Tsis-oxide ceramics tsuas yog hais txog nitride ceramics, carbide ceramics, boride ceramics thiab silicide ceramics. Lawv feem ntau sib raug zoo los ntawm cov ntawv cog lus muajalent ruaj khov, thiab tsis muaj hlau oxide ceramic raw khoom tsis tshua muaj nyob hauv xwm. Nws yog qhov tsim nyog yuav tsum coj los ua cov khoom siv raw, thiab tom qab ntawd ua cov khoom siv ceramic raws li cov txheej txheem ceramic. Tsab ntawv xov xwm no yuav qhia luv luv txog tsib hom kev cai neeg tsis xeb hlau uas tsis muaj oxide.
Icon Silicon Nitride Ceramic
Silicon nitride (Si3N4) yog covalent daim ntawv cog lus sib txuas, uas muaj ob lub hom siv lead ua, uas yog α-Si3N4 thiab β-Si3N4. α-Si3N4 yog cov siv lead ua cov pob zeb ci, β-Si3N4 yog koob siv lead ua koob, ob qho tam li yog los ntawm hexagonal cov qauv siv lead ua. Vim tias qhov kub thiab hnav tsis kam ntawm Si3N4 ceramics, zoo thermal shock tsis kam, corrosion tsis kam, tsis tshua muaj kev sib txhuam thiab tsis tshua muaj thermal nthuav coefficient, nws tau siv dav hauv ntau thaj chaw muaj.
▼ Boron Nitride Ceramic
Cov qauv thiab qee cov khoom ntawm boron nitride (BN) zoo ib yam li graphite, thiab nws muaj ob hom siv lead ua: hexagonal thiab cubic. Hexagonal tuaj yeem hloov mus rau hauv cubic BN ntawm 1,300-1,800 ℃ thiab 6.5MPa, thiab nws cov hardness yog thib ob rau pob zeb diamond. Cov khoom siv BN nrog hexagonal lub ntsiab crystalline theem muaj kev ua haujlwm, dawb lubricity, thiab cov khoom zoo thermal. Nws yog qhov zoo tshaj plaws hluav taws xob insulating thiab kub-dissipating cov khoom ntawm qhov kub siab ib puag ncig thiab tseem yog qhov ua tau zoo tshaj hlau ntim cov khoom ntim.
Icon Silicon Carbide Ceramic
Silicon carbide (SiC) ceramics muaj ob hom siv lead ua, ib qho yog α-SiC, uas yog los ntawm hexagonal cov qauv siv lead ua. Nws yog qhov siab-siab ruaj khov hom; lwm qhov yog β-SiC, uas yog cov cubic siv lead ua qhov nruab nrab thiab yog cov tsawg-ruaj ruaj hom. α-SiC tuaj yeem hloov pauv mus ua β-SiC cov qauv siv lead ua hauv qhov kub thiab txias ntawm 2,100-2,400 ℃. Silicon carbide ceramics muaj qhov kub thiab txias zog, kev ua haujlwm siab, kev ua haujlwm siab, hnav tsis kam, kev txhim kho corrosion, oxidation tsis kam, siab thermal conductivity, thiab zoo thermal stability, yog li nws yog qhov zoo-kub qauv ceramic khoom saum toj no 1,400 ℃. Thaum xub thawj nws tsuas yog siv los ua cov khoom siv refractory thiab abrasives, xws li cov hlau ua cov tsis muaj hlau, cov kab hluav taws sov, cov rooj tog qhov cub, cov rooj tog sib tsoo, thiab lwm yam. xws li cov foob pob hluav taws tso cov twj tso kua mis tsis muaj zog, lub tshuab tso pa roj hauv tshuab hluav taws xob, tshuab hluav taws xob ntawm cov tshuab nqus dej muaj hluav taws xob, lub tshuab hluav taws xob cua sov ua kom sov, thiab lwm yam
▼ Boron Carbide Ceramic
Boron carbide muaj cov yam ntxwv ntawm kev tsis tshua muaj siab, siab zog, siab kev nyab xeeb thiab zoo tshuaj lom neeg ruaj khov. Kuj hu ua pob zeb diamond dub, nws yog cov tshuaj lom neeg inorganic nrog cov tshuaj lom neeg tshuaj ntawm B₄C, feem ntau grey-dub. B₄C yog ib qho ntawm peb cov khoom siv tawv (thib ob rau pob zeb diamond thiab cubic boron nitride). Piv nrog pob zeb diamond thiab cubic boron nitride, boron carbide yog qhov yooj yim tsim khoom thiab tus nqi qis, yog li nws tau siv dav dua. Nws tuaj yeem hloov lub pob zeb diamond kim hauv qee qhov chaw thiab feem ntau siv hauv kev sib tsoo, drilling thiab lwm yam. Boron carbide feem ntau yog siv nyob rau hauv lub txhab hlau, thaiv lub cev, thiab siv ntau yam kev lag luam. Boron carbide tuaj yeem nqus tau ntau ntawm neutron yam tsis tau ua ib lub isotopes hluav taws xob, yog li nws yog qhov zoo tshaj plaws neutron absorber hauv chaw tsim hluav taws xob nuclear.
