Imiterere yikirahure
Imiterere ya fiziki ya chimique yikirahure ntabwo igenwa gusa nimiterere yimiti, ahubwo ifitanye isano rya bugufi nimiterere yayo.Gusa mugusobanukirwa isano yimbere hagati yimiterere, ibiyigize, imiterere nimikorere yikirahure, birashoboka gukora ibikoresho byibirahure cyangwa ibicuruzwa bifite imiterere-karemano ya fiziki-chimique uhindura imiterere yimiti, amateka yubushyuhe cyangwa ukoresheje uburyo bumwe na bumwe bwo kuvura umubiri.
Ibiranga ikirahure
Ikirahuri ni ishami rya amorphous ikomeye, ni ibikoresho bya amorphous bifite imiterere ikomeye ya mashini.Bikunze kwitwa "supercooled fluid".Muri kamere, hariho leta ebyiri zingingo zikomeye: leta nziza na leta itari nziza.Ibintu byitwa leta idatanga umusaruro nuburyo ibintu bikomeye byabonetse muburyo butandukanye kandi burangwa nihungabana ryimiterere.Imiterere yikirahure nubwoko butari busanzwe bukomeye.Atome ziri mu kirahure ntizifite intera ndende itondekanya mu kirere nka kirisiti, ariko birasa n'amazi kandi bifite gahunda ngufi byateganijwe.Ikirahure kirashobora kugumana imiterere runaka nkikomeye, ariko ntameze nkamazi atemba munsi yuburemere bwayo.Ibintu by'ibirahure bifite ibintu by'ingenzi bikurikira.
.Kubwibyo, mugihe nta guhangayika kwimbere mubirahure, imiterere yumubiri na chimique (nkubukomere, modulus ya elastique, coefficente yo kwagura amashyuza, ubushyuhe bwumuriro, indangagaciro zivunika, imiyoboro, nibindi) birasa mubyerekezo byose.Ariko, mugihe habaye impagarara mubirahure, uburinganire bwimiterere buzasenywa, kandi ikirahure kizerekana anisotropy, nkuburyo butandukanye bwo gutandukanya inzira nziza.
(2) Metastability
Impamvu ikirahuri kimeze neza ni uko ikirahuri kiboneka mugukonjesha vuba gushonga.Bitewe no kwiyongera gukabije kwijimye mugihe cyo gukonjesha, ibice ntibigira umwanya wo gukora gahunda ihoraho ya kristu, kandi ingufu zimbere muri sisitemu ntabwo ziri ku giciro cyo hasi, ariko muburyo bworoshye;Nubwo, nubwo ikirahuri kiri mumbaraga zisumba izindi, ntigishobora guhita gihinduka mubicuruzwa kubera ubwinshi bwacyo mubushyuhe bwicyumba;Gusa mubihe bimwe byo hanze, nukuvuga, tugomba gutsinda inzitizi yibintu biva mubirahuri bikagera kuri kristaline, ikirahure gishobora gutandukana.Kubwibyo, duhereye kubintu bya termodinamike, ikirahuri imiterere ntigihinduka, ariko duhereye kubitekerezo bya kinetics, irahagaze.Nubwo ifite imyumvire yo kurekura ubushyuhe ihinduka muri kristu hamwe nimbaraga nke zimbere, amahirwe yo guhinduka mumiterere ya kristu ni nto cyane mubushyuhe bwicyumba, ikirahuri rero kikaba kimeze neza.
(3) Nta ngingo ihamye yo gushonga
Guhindura ibintu byikirahure kuva mubikomeye kugeza mumazi bikorwa mubipimo runaka byubushyuhe (impinduka yubushyuhe bwo guhinduka), bitandukanye nibintu bya kristaline kandi bidafite aho bihurira.Iyo ikintu gihinduwe kuva gushonga kigahinduka, niba ari inzira yo korohereza ibintu, hazashyirwaho ibyiciro bishya muri sisitemu, kandi ubushyuhe bwa kristu, ibintu nibindi byinshi bizahinduka gitunguranye.
Mugihe ubushyuhe bugabanutse, ubwiza bwashonga bwiyongera, amaherezo ikirahure gikomeye kirakorwa.Igikorwa cyo gukomera cyarangiye mubushyuhe bugari, kandi nta kristu nshya yashizweho.Ubushyuhe bwo kuva mu gushonga kugera ku kirahure gikomeye biterwa n’imiterere yimiti yikirahure, muri rusange ihindagurika muri dogere mirongo kugeza kuri magana, bityo ikirahuri ntigifite aho gishonga, ariko cyoroheje gusa.Muri uru rwego, ikirahure gihinduka buhoro buhoro kuva viscoplastique kijya kuri viscoelastic.Guhindura buhoro buhoro iyi mitungo niyo shingiro yikirahure hamwe nibikorwa byiza.
(4) Gukomeza no guhindura ihinduka ryumutungo
Uburyo bwo guhindura imitungo yibirahuri kuva kumashanyarazi gushika kumiterere ihamye birakomeza kandi birahindurwa, aho hari igice cyakarere k’ubushyuhe kaba plastiki, bita "guhinduka" cyangwa "akarere kadasanzwe", aho imitungo ifite impinduka zidasanzwe.
Mugihe cyo gutegera, imitungo irahinduka nkuko bigaragara kumurongo ABCD, t.Nibintu bishonga byibikoresho.Iyo ikirahuri cyakozwe na supercooling, inzira irahinduka nkuko bigaragara kumurongo wa abkfe.T ni ubushyuhe bwikirahure, t nubushyuhe bwikirahure.Kubirahuri bya oxyde, viscosity ihuye nizi ndangagaciro zombi ni 101pa · s na 1005p · s.
Imiterere yuburyo bwikirahure kimenetse
"Imiterere yikirahure" bivuga imiterere ya geometrike ya ion cyangwa atome mumwanya hamwe nuburyo bukora mubirahure.Ubushakashatsi ku miterere y'ibirahure bwashyize mu bikorwa imbaraga n'ubwenge bw'abahanga benshi b'ibirahure.Kugerageza kwa mbere gusobanura ishingiro ryikirahure ni g.hypothesis ya tamman yibirenze, ifata ko ikirahuri ari amazi arenze urugero, Inzira yikirahure ikomera kuva gushonga ikagera ni inzira yumubiri gusa, ni ukuvuga ko kugabanuka kwubushyuhe, molekile yikirahure yegera buhoro buhoro kubera kugabanuka kwingufu za kinetic , kandi imbaraga zikorana zigenda ziyongera buhoro buhoro, bigatuma urwego rwikirahure rwiyongera, kandi amaherezo rukora ibintu byuzuye kandi bidasanzwe.Abantu benshi bakoze imirimo myinshi.Igitekerezo gikomeye cyane cyimiterere yikirahure kigezweho ni: inyigisho yibicuruzwa, igitekerezo cyurusobe rudasanzwe, tewolojiya ya gel, inyigisho eshanu zifatika, inyigisho za polymer nibindi.Muri byo, ibisobanuro byiza byikirahure nigitekerezo cyibicuruzwa numuyoboro udasanzwe.
Igitekerezo cya Crystal
Randell l yashyize imbere ibitekerezo bya kristu yuburyo bwimiterere yikirahure mumwaka wa 1930, kubera ko imirasire yimirahuri yibirahuri bimwe bisa nkibya kristu yibintu bimwe.Yatekereje ko ikirahuri kigizwe na microcrystalline nibikoresho bya amorphous.Microproduct ifite gahunda ya atome isanzwe kandi imipaka igaragara hamwe nibikoresho bya amorphous.Ingano ya microproduct ni 1.0 ~ 1.5nm, nibiyirimo birenga 80%.Icyerekezo cya microcrystalline kirahungabanye.Mu kwiga annealing yikirahure cya optique, Lebedev yasanze habaye impinduka zitunguranye kumurongo wibipimo byerekana ibirahure hamwe nubushyuhe kuri 520 ℃.Yasobanuye iki kintu nkimpinduka imwe ya quartz “microcrystalline” mubirahuri kuri 520 ℃.Lebedev yizeraga ko ikirahuri kigizwe na “kristu” nyinshi, zitandukanye na microcrystalline, Guhinduka kuva “kristu” kugera mu karere ka amorphous birangira intambwe ku yindi, kandi nta mipaka igaragara hagati yabo.
Igihe cyo kohereza: Gicurasi-31-2021