Karbid k\u0159em\u00edku, \u010dast\u011bji ozna\u010dovan\u00fd jako karborundum nebo SiC, je tvrd\u00fd keramick\u00fd materi\u00e1l s mnoha aplikacemi. Tato v\u0161estrann\u00e1 l\u00e1tka slou\u017e\u00ed jako brusivo, m\u00e1 \u0161irokop\u00e1smov\u00e9 polovodi\u010dov\u00e9 vlastnosti a lze z n\u00ed vyr\u00e1b\u011bt i konstruk\u010dn\u00ed keramick\u00e9 prvky.<\/p>\n
V\u00fdroba zahrnuje reakci a pyrol\u00fdzu polysiloxan\u016f pod tlakem, rozemlet\u00ed do pr\u00e1\u0161kov\u00e9 formy, sp\u00e9k\u00e1n\u00ed do pevn\u00fdch tvar\u016f a n\u00e1sledn\u00e9 mlet\u00ed pro kone\u010dn\u00e9 mikrostrukturn\u00ed tvarov\u00e1n\u00ed. Ka\u017ed\u00fd krok hraje ned\u00edlnou roli p\u0159i v\u00fdrob\u011b tohoto fin\u00e1ln\u00edho materi\u00e1lu s r\u016fzn\u00fdmi v\u00fdsledky v z\u00e1vislosti na pou\u017eit\u00fdch metod\u00e1ch tv\u00e1\u0159en\u00ed, kter\u00e9 maj\u00ed v\u00fdznamn\u00fd vliv na mikrostrukturu.<\/p>\n
Hust\u00e9 slo\u017een\u00ed karbidu k\u0159em\u00edku hraje kl\u00ed\u010dovou roli v jeho schopnosti odol\u00e1vat chemick\u00e9mu, tepeln\u00e9mu a mechanick\u00e9mu nam\u00e1h\u00e1n\u00ed. D\u00edky vynikaj\u00edc\u00ed tvrdosti a tepeln\u00e9 vodivosti je karbid k\u0159em\u00edku vynikaj\u00edc\u00ed volbou materi\u00e1lu pro vysoce v\u00fdkonn\u00e9 a vysoce nam\u00e1han\u00e9 aplikace.<\/p>\n
Hust\u0161\u00ed materi\u00e1ly jsou obvykle odoln\u011bj\u0161\u00ed proti korozi a opot\u0159eben\u00ed. Krom\u011b toho d\u00edky n\u00edzk\u00e9 m\u00ed\u0159e rozta\u017enosti a smr\u0161\u0165ov\u00e1n\u00ed l\u00e9pe odol\u00e1vaj\u00ed extr\u00e9mn\u00edm teplot\u00e1m, co\u017e je ide\u00e1ln\u00ed pro elektrick\u00e9 a plynov\u00e9 syst\u00e9my.<\/p>\n
SiC je tak\u00e9 vysoce odoln\u00fd v\u016f\u010di z\u00e1\u0159en\u00ed a m\u00e1 v porovn\u00e1n\u00ed s jin\u00fdmi polovodi\u010di neobvykle velkou p\u00e1smovou mezeru, co\u017e mu umo\u017e\u0148uje pracovat p\u0159i mnohem vy\u0161\u0161\u00edch teplot\u00e1ch, nap\u011bt\u00edch a frekvenc\u00edch ne\u017e jeho kolegov\u00e9. SiC se proto pou\u017e\u00edv\u00e1 v cel\u00e9 \u0159ad\u011b elektronick\u00fdch a pr\u016fmyslov\u00fdch aplikac\u00ed, v\u010detn\u011b v\u00fdroby energie, leteck\u00e9ho a automobilov\u00e9ho pr\u016fmyslu.<\/p>\n
Dosa\u017een\u00ed vysok\u00fdch hustot SiC m\u016f\u017ee b\u00fdt u velk\u00fdch komponent n\u00e1ro\u010dn\u00e9. D\u00edky technologii rampov\u00e9 komprese je v\u0161ak nyn\u00ed mo\u017en\u00e9 dos\u00e1hnout rovnom\u011brn\u00e9 hustoty a\u017e 98% teoretick\u00e9 hustoty. Proces zahrnuje vytvo\u0159en\u00ed homogenn\u00ed disperze pr\u00e1\u0161kov\u00e9 sm\u011bsi submikronov\u00e9 velikosti sest\u00e1vaj\u00edc\u00ed p\u0159ev\u00e1\u017en\u011b z karbidu k\u0159em\u00edku s p\u0159\u00edsadou obsahuj\u00edc\u00ed b\u00f3r; pot\u00e9 se tato pr\u00e1\u0161kov\u00e1 sm\u011bs tvaruje do zelen\u00fdch t\u011bles a n\u00e1sledn\u011b se sp\u00e9k\u00e1 p\u0159i teplot\u011b 1900-2100 stup\u0148\u016f C za podm\u00ednek \u0159\u00edzen\u00e9 atmosf\u00e9ry.<\/p>\n
P\u0159\u00edsady obsahuj\u00edc\u00ed b\u00f3r by se m\u011bly p\u0159id\u00e1vat b\u011bhem m\u00edch\u00e1n\u00ed pr\u00e1\u0161ku v mno\u017estv\u00ed odpov\u00eddaj\u00edc\u00edm jednomu hmotnostn\u00edmu d\u00edlu element\u00e1rn\u00edho b\u00f3ru na 100 d\u00edl\u016f karbidu k\u0159em\u00edku, aby se dos\u00e1hlo bezpe\u010dn\u00e9ho zhutn\u011bn\u00ed bez segregace na hranic\u00edch zrn.<\/p>\n
Karbid k\u0159em\u00edku (C-Si) je um\u011bl\u00fd materi\u00e1l slo\u017een\u00fd z uhl\u00edku (C) a k\u0159em\u00edku (Si). M\u00e1 druhou nejtvrd\u0161\u00ed Mohsovu tvrdost po karbidu boru (9) a nab\u00edz\u00ed v\u00fdjime\u010dnou pevnost, odolnost proti opot\u0159eben\u00ed a korozi; ve skute\u010dnosti dokonce vydr\u017e\u00ed p\u016fsoben\u00ed kyseliny fluorovod\u00edkov\u00e9 a s\u00edrov\u00e9, ani\u017e by zkorodoval - nav\u00edc ho nerozpust\u00ed ani voda, v\u011bt\u0161ina chemik\u00e1li\u00ed v\u010detn\u011b z\u00e1sad! Karbid k\u0159em\u00edku je d\u00edky sv\u00e9 v\u0161estrannosti jako technick\u00fd materi\u00e1l obl\u00edben\u00fd i mezi v\u011bdci.<\/p>\n
Vzhledem k tomu, \u017ee \u0161mirgl odol\u00e1v\u00e1 vysokorychlostn\u00edm \u0159ezac\u00edm a brusn\u00fdm operac\u00edm a pou\u017e\u00edv\u00e1 se i pro abrazivn\u00ed trysk\u00e1n\u00ed a obr\u00e1b\u011bn\u00ed, je d\u00edky sv\u00e9 trvanlivosti a cenov\u00e9 v\u00fdhodnosti \u0161iroce vyu\u017e\u00edv\u00e1n pro modern\u00ed lapid\u00e1rn\u00ed pr\u00e1ce. Krom\u011b toho slou\u017e\u00ed jako d\u016fle\u017eit\u00e1 surovina p\u0159i v\u00fdrob\u011b brusn\u00fdch a le\u0161tic\u00edch sm\u011bs\u00ed.<\/p>\n
Karbid k\u0159em\u00edku se stal z\u00e1kladn\u00edm materi\u00e1lem kosmick\u00fdch technologi\u00ed d\u00edky sv\u00e9 mimo\u0159\u00e1dn\u00e9 trvanlivosti a odolnosti v\u016f\u010di radiaci. Zrcadla vyroben\u00e1 z karbidu k\u0159em\u00edku se proto stala volbou pro n\u011bkolik nejv\u011bt\u0161\u00edch teleskop\u016f, jako jsou mise Herschel a BepiColombo, nebo mohou b\u00fdt dokonce zhotovena do pevn\u00fdch r\u00e1m\u016f, kter\u00e9 odol\u00e1vaj\u00ed teplot\u00e1m vyskytuj\u00edc\u00edm se na Venu\u0161i a \u00farovn\u00edm z\u00e1\u0159en\u00ed, kter\u00e9 p\u0159ekra\u010duj\u00ed o\u010dek\u00e1v\u00e1n\u00ed.<\/p>\n
Ned\u00e1vn\u00e9 experiment\u00e1ln\u00ed poznatky ukazuj\u00ed, \u017ee a-SiC je ve sv\u00e9 f\u00e1zi B1 stabiln\u00ed v \u0161irok\u00e9m rozsahu podm\u00ednek, kter\u00e9 odpov\u00eddaj\u00ed p\u0159edpokl\u00e1dan\u00fdm podm\u00ednk\u00e1m v pl\u00e1\u0161ti exoplanet bohat\u00fdch na uhl\u00edk, na rozd\u00edl od jeho chov\u00e1n\u00ed na Zemi, kde se rychle rozkl\u00e1d\u00e1 na oxid k\u0159emi\u010dit\u00fd a kysl\u00edk.<\/p>\n
Karbid k\u0159em\u00edku, \u010dast\u011bji ozna\u010dovan\u00fd jako SiC, je chemick\u00e1 slou\u010denina slo\u017een\u00e1 z k\u0159em\u00edku (atomov\u00e9 \u010d\u00edslo 14) a uhl\u00edku (atomov\u00e9 \u010d\u00edslo 6). M\u00e1 opalizuj\u00edc\u00ed zelen\u00fd a\u017e modro\u010dern\u00fd vzhled s neho\u0159lav\u00fdmi vlastnostmi; jeho hustota je 3,21 g na cm3.<\/p>\n
Karbid k\u0159em\u00edku se v omezen\u00e9m mno\u017estv\u00ed p\u0159irozen\u011b vyskytuje v meteoritech, lo\u017eisc\u00edch korundu a kimberlitu; v\u011bt\u0161ina karbidu k\u0159em\u00edku pou\u017e\u00edvan\u00e9ho v elektronick\u00fdch za\u0159\u00edzen\u00edch se v\u0161ak vyr\u00e1b\u00ed synteticky. Edward Acheson poprv\u00e9 synteticky syntetizoval karbid k\u0159em\u00edku v roce 1891, kdy\u017e se pokou\u0161el vytvo\u0159it um\u011bl\u00e9 diamanty zah\u0159\u00edv\u00e1n\u00edm hl\u00edny a pr\u00e1\u0161kov\u00e9ho koksu v elektrick\u00e9 obloukov\u00e9 peci; p\u0159itom si v\u0161iml jasn\u011b zelen\u00fdch krystal\u016f, kter\u00e9 vypadaly podobn\u011b jako diamant, p\u0159ipojen\u00fdch k uhl\u00edkov\u00fdm elektrod\u00e1m, a pojmenoval tyto krystaly \u201cmoissanit\u201d podle druhu kamene, kter\u00e9mu se podobaly.<\/p>\n
SiC je polovodi\u010dov\u00fd materi\u00e1l s extr\u00e9mn\u011b \u0161irokou p\u00e1smovou mezerou, co\u017e mu umo\u017e\u0148uje pracovat p\u0159i vy\u0161\u0161\u00edch teplot\u00e1ch a nap\u011bt\u00edch ne\u017e jin\u00fdm polovodi\u010dov\u00fdm materi\u00e1l\u016fm. D\u00edky sv\u00e9 vynikaj\u00edc\u00ed tepeln\u00e9 vodivosti rychle odv\u00e1d\u00ed teplo a jeho hust\u00e1 krystalick\u00e1 struktura zaji\u0161\u0165uje vynikaj\u00edc\u00ed odolnost proti opot\u0159eben\u00ed - ide\u00e1ln\u00ed pro aplikace, jako jsou \u0159ezn\u00e9 n\u00e1stroje.<\/p>\n
Laborato\u0159e EAG maj\u00ed rozs\u00e1hl\u00e9 zku\u0161enosti s anal\u00fdzou SiC pomoc\u00ed objemov\u00fdch i prostorov\u011b rozli\u0161en\u00fdch analytick\u00fdch technik. SiC je mimo\u0159\u00e1dn\u011b u\u017eite\u010dn\u00fd materi\u00e1l pro v\u00fdrobu polovodi\u010d\u016f, proto\u017ee m\u016f\u017ee b\u00fdt dopov\u00e1n r\u016fzn\u00fdmi prvky, kter\u00e9 m\u011bn\u00ed jeho elektrotermick\u00e9 vlastnosti. Zaji\u0161t\u011bn\u00ed koncentrace a prostorov\u00e9ho rozlo\u017een\u00ed dopant\u016f p\u0159i sou\u010dasn\u00e9 eliminaci ne\u017e\u00e1douc\u00edch kontaminant\u016f je p\u0159i vytv\u00e1\u0159en\u00ed vysoce kvalitn\u00edch polovodi\u010dov\u00fdch v\u00fdrobk\u016f prvo\u0159ad\u00e9.<\/p>\n
Karbid k\u0159em\u00edku je extr\u00e9mn\u011b hutn\u00fd materi\u00e1l a jedna z nejtvrd\u0161\u00edch dostupn\u00fdch l\u00e1tek, kter\u00e1 jako keramick\u00fd materi\u00e1l poskytuje vynikaj\u00edc\u00ed odolnost proti korozi, co\u017e by mohlo omezit aktivn\u00ed chladic\u00ed syst\u00e9my v elektrick\u00fdch vozidlech.<\/p>\n
Karbid k\u0159em\u00edku (SiC) je kovalentn\u011b v\u00e1zan\u00e1 sv\u011btle \u0161ed\u00e1 pevn\u00e1 l\u00e1tka s relativn\u00ed tvrdost\u00ed diamantu na Mohsov\u011b stupnici. \u017d\u00e1ruvzdorn\u00e9 materi\u00e1ly s t\u011bmito vlastnostmi jsou ide\u00e1ln\u00ed pro pou\u017eit\u00ed, proto\u017ee SiC m\u00e1 vysokou teplotu t\u00e1n\u00ed, tepelnou vodivost a n\u00edzkou tepelnou rozta\u017enost.<\/p>\n
Karbid k\u0159em\u00edku m\u016f\u017ee b\u00fdt dopov\u00e1n dus\u00edkem nebo fosforem, \u010d\u00edm\u017e vznikne polovodi\u010d typu n, nebo m\u016f\u017ee b\u00fdt dopov\u00e1n beryliem, b\u00f3rem, hlin\u00edkem a heliem, \u010d\u00edm\u017e vznikne polovodi\u010d typu p. D\u00edky sv\u00e9mu \u0161irok\u00e9mu p\u00e1smov\u00e9mu \u00faseku, kter\u00fd mu umo\u017e\u0148uje zpracov\u00e1vat t\u0159ikr\u00e1t vy\u0161\u0161\u00ed nap\u011bt\u00ed ne\u017e standardn\u00ed k\u0159em\u00edkov\u00e9 polovodi\u010de. Karbid k\u0159em\u00edku se d\u00edky sv\u00e9mu \u0161irok\u00e9mu vyu\u017eit\u00ed jako materi\u00e1l pro v\u00fdrobu elektronick\u00fdch sou\u010d\u00e1stek stal obl\u00edben\u00fdm materi\u00e1lem pro v\u00fdrobu elektronick\u00fdch za\u0159\u00edzen\u00ed.<\/p>\n
P\u0159\u00edrodn\u00ed lo\u017eiska SiC existuj\u00ed v n\u011bkter\u00fdch vzorc\u00edch meteorit\u016f, korundov\u00fdch lo\u017eisk\u00e1ch a kimberlitu, ale v\u011bt\u0161ina pr\u016fmyslov\u00e9ho SiC se vyr\u00e1b\u00ed synteticky. Varianty SSiC a SiSiC pat\u0159\u00ed d\u00edky sv\u00fdm tepeln\u00fdm vlastnostem k nej\u010dast\u011bji vyu\u017e\u00edvan\u00fdm materi\u00e1l\u016fm pro n\u00e1ro\u010dn\u00e9 podm\u00ednky, jako je 3D tisk, v\u00fdroba balistick\u00fdch p\u0159edm\u011bt\u016f, chemick\u00e1 v\u00fdroba a aplikace v energetick\u00fdch technologi\u00edch, jako\u017e i komponenty potrubn\u00edch syst\u00e9m\u016f; jejich vy\u0161\u0161\u00ed hustota ne\u017e u \u010dist\u00e9ho k\u0159emene \u010din\u00ed z t\u011bchto slou\u010denin atraktivn\u00ed n\u00e1hradu kov\u016f a nab\u00edzej\u00ed dobrou tuhost, tvrdost a odolnost v\u016f\u010di vysok\u00fdm teplot\u00e1m, kter\u00e9 ve srovn\u00e1n\u00ed s \u010dist\u00fdm k\u0159emenem a odolnost\u00ed v\u016f\u010di vysok\u00fdm teplot\u00e1m konkuruj\u00ed tepeln\u00fdm vlastnostem \u010dist\u00e9ho k\u0159emene, co\u017e z t\u011bchto slou\u010denin \u010din\u00ed atraktivn\u00ed alternativu n\u00e1hrady kov\u016f.<\/p>","protected":false},"excerpt":{"rendered":"
Silicon carbide, more commonly referred to as Carborundum or SiC, is a hard ceramic material with numerous applications. This versatile […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""}},"footnotes":""},"categories":[3],"tags":[],"class_list":["post-90","post","type-post","status-publish","format-standard","hentry","category-sic-knowledge"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/posts\/90","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/comments?post=90"}],"version-history":[{"count":1,"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/posts\/90\/revisions"}],"predecessor-version":[{"id":91,"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/posts\/90\/revisions\/91"}],"wp:attachment":[{"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/media?parent=90"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/categories?post=90"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/tags?post=90"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}