Technical ceramics muaj lub zog txhua yam, hardness, hnav tsis kam, kub tsis kam, thiab tsawg ntom. Nyob rau hauv cov nqe lus ntawm conductivity, nws yog ib qho zoo heev hluav taws xob thiab thermal insulator khoom.
Tom qab lub thermal poob siab, uas yog cua kub ceev uas ua rau cov ceramic nthuav, cov ceramic tuaj yeem tswj qhov kub thiab txias hloov tam sim ntawd yam tsis muaj kev tawg, tawg, lossis poob nws lub zog txhua yam.
Thermal shock, tseem hu ua "thermal collapse," yog disintegration ntawm tej yam khoom uas tshwm sim los ntawm ib tug tam sim ntawd kub hloov. Qhov kub hloov pauv yuav tsis zoo lossis zoo, tab sis nws yuav tsum yog qhov tseem ceeb hauv ob qho xwm txheej.
Mechanical stresses tsim ntawm cov khoom sab nrauv (plhaub) thiab sab hauv (core) raws li nws heats los yog txias sai rau sab nraud tshaj sab hauv.
Cov khoom yog irreparably puas thaum lub kub txawv tshaj ib tug tej yam pib. Cov hauv qab no muaj feem cuam tshuam rau qhov ntsuas kub tseem ceeb no:
Hloov ib lossis ntau dua ntawm cov no feem ntau tuaj yeem txhim kho kev ua tau zoo, tab sis nrog rau txhua daim ntawv thov ceramic, thermal shock tsuas yog ib feem ntawm qhov sib npaug, thiab txhua qhov kev hloov pauv yuav tsum xav txog hauv cov ntsiab lus ntawm txhua qhov kev ua tau zoo.
Thaum tsim cov khoom siv ceramic, nws yog ib qho tseem ceeb uas yuav tsum xav txog tag nrho cov kev xav tau thiab nquag nrhiav kev sib haum xeeb zoo tshaj plaws.
Thermal shock feem ntau yog thawj qhov ua rau tsis ua haujlwm hauv cov ntawv thov kub. Nws yog tsim los ntawm peb yam: thermal expansion, thermal conductivity, thiab lub zog. Kev hloov pauv kub ceev, ob qho tib si nce thiab nqis, ua rau qhov sib txawv ntawm qhov kub thiab txias, zoo ib yam li qhov tawg uas tshwm sim los ntawm rub lub khob dej khov rau lub khob kub. Vim qhov sib txawv ntawm kev nthuav dav thiab kev cog lus, kev txav mus los ua rau tawg thiab tsis ua haujlwm.
Tsis muaj cov kev daws teeb meem yooj yim rau cov teeb meem ntawm thermal shock, tab sis cov lus qhia hauv qab no yuav pab tau:
Xaiv cov khoom siv qib uas muaj qee qhov kev cuam tshuam ntawm thermal shock tab sis ua tau raws li qhov yuav tsum tau ua ntawm daim ntawv thov. Silicon carbides zoo heev. Alumina-raws li cov khoom lag luam tsis tshua xav tau, tab sis lawv tuaj yeem txhim kho nrog kev tsim kom zoo. Cov khoom porous feem ntau zoo dua li cov impervious vim lawv tuaj yeem tiv taus qhov kub thiab txias ntau dua.
Cov khoom uas muaj cov phab ntsa nyias zoo dua cov uas muaj phab ntsa tuab. Tsis tas li ntawd, tsis txhob loj thickness hloov mus thoob plaws ib feem. Cov khoom seem yuav zoo dua vim tias lawv muaj qhov loj me thiab cov qauv tsim ua ntej uas txo cov kev ntxhov siab.
Tsis txhob siv cov ces kaum ntse, vim cov no yog qhov chaw tseem ceeb rau cov kab nrib pleb. Tsis txhob muab qhov nro ntawm cov ceramic. Cov khoom tuaj yeem tsim los ua ntej kev ntxhov siab los pab daws qhov teeb meem no. Tshawb xyuas cov txheej txheem thov kom pom tias nws muaj peev xwm muab qhov hloov pauv hloov pauv, xws li los ntawm preheating lub ceramic los yog qeeb tus nqi hloov pauv.
