Karbid k\u0159em\u00edku, \u010dast\u011bji ozna\u010dovan\u00fd zkratkou SiC, je brusn\u00fd materi\u00e1l slo\u017een\u00fd z k\u0159em\u00edku a uhl\u00edku, kter\u00fd se pr\u016fmyslov\u011b vyr\u00e1b\u00ed od konce 19. stolet\u00ed a pou\u017e\u00edv\u00e1 se jako brusivo. Krom\u011b toho se p\u0159\u00edrodn\u00ed lo\u017eiska SiC nach\u00e1zej\u00ed v miner\u00e1ln\u00edch formac\u00edch moissanitu.<\/p>\n
Keramick\u00e9 glazury obsahuj\u00ed pr\u00e1\u0161ek t\u00e9to l\u00e1tky, kter\u00fd po p\u0159id\u00e1n\u00ed do keramick\u00e9 pece vytv\u00e1\u0159\u00ed bublinky skla, kter\u00e9 dod\u00e1vaj\u00ed vizu\u00e1ln\u00ed a texturn\u00ed p\u0159ita\u017elivost.<\/p>\n
Karbid k\u0159em\u00edku je extr\u00e9mn\u011b tvrd\u00e1 l\u00e1tka, kter\u00e1 se pou\u017e\u00edv\u00e1 jako tryskac\u00ed prost\u0159edek p\u0159i brou\u0161en\u00ed materi\u00e1l\u016f a jej\u00ed\u017e hodnota se na Mohsov\u011b stupnici bl\u00ed\u017e\u00ed diamantu. Krom\u011b toho je tento keramick\u00fd materi\u00e1l sou\u010d\u00e1st\u00ed brusn\u00fdch kotou\u010d\u016f a \u0159ezn\u00fdch n\u00e1stroj\u016f a nach\u00e1z\u00ed se tak\u00e9 ve v\u00fdrobc\u00edch, jako jsou smirkov\u00e9 pl\u00e1tno, brusn\u00fd pap\u00edr a podr\u00e1\u017eky bot, \u017e\u00e1ruvzdorn\u00e9 cihly pro pece v ne\u017eelezn\u00e9 metalurgii a keramick\u00e9m pr\u016fmyslu jako \u017e\u00e1ruvzdorn\u00e9 cihly v pec\u00edch v ne\u017eelezn\u00e9 metalurgii jako \u017e\u00e1ruvzdorn\u00e9 cihly \u017e\u00e1ruvzdorn\u00e9 cihly na pec\u00edch v ne\u017eelezn\u00e9 metalurgii nebo ve vysokoteplotn\u00edch aplikac\u00edch, jako jsou keramick\u00e9 desky v nepr\u016fst\u0159eln\u00fdch vest\u00e1ch.<\/p>\n
Brusn\u00e9 vlastnosti karbidu k\u0159em\u00edku vypl\u00fdvaj\u00ed z jeho vrstevnat\u00e9 krystalov\u00e9 struktury. Ka\u017ed\u00fd atom uhl\u00edku se v\u00e1\u017ee se \u010dty\u0159mi atomy k\u0159em\u00edku v oktaedrick\u00e9 konfiguraci, co\u017e zaji\u0161\u0165uje siln\u00e9 vazebn\u00e9 vlastnosti - tento materi\u00e1l je tak jednou z m\u00e1la syntetick\u00fdch l\u00e1tek s takov\u00fdmi vlastnostmi, kter\u00e9 p\u016fsobiv\u011b vypov\u00eddaj\u00ed o v\u00fdkonnosti pr\u016fmyslov\u00fdch aplikac\u00ed.<\/p>\n
Zrcadla z karbidu k\u0159em\u00edku jsou d\u00edky sv\u00e9 tuhosti, n\u00edzk\u00e9 tepeln\u00e9 rozta\u017enosti a pevnostn\u00edm vlastnostem ide\u00e1ln\u00edm materi\u00e1lem pro pou\u017eit\u00ed v astronomick\u00fdch dalekohledech. Herschel\u016fv vesm\u00edrn\u00fd dalekohled i vesm\u00edrn\u00fd dalekohled Gaia pou\u017e\u00edvaj\u00ed k odrazu sv\u011btla zrcadla z karbidu k\u0159em\u00edku. Chemick\u00e1 depozice z plynn\u00e9 f\u00e1ze poskytuje \u00fa\u010dinn\u00fd prost\u0159edek pro vytv\u00e1\u0159en\u00ed t\u011bchto materi\u00e1l\u016f, proto\u017ee k\u0159em\u00edk a uhl\u00edk rostou spole\u010dn\u011b do polykrystalick\u00fdch vrstev na sklen\u011bn\u00fdch substr\u00e1tech.<\/p>\n
Polovodi\u010de z karbidu k\u0159em\u00edku dos\u00e1hly v\u00fdznamn\u00e9ho pokroku v automobilov\u00e9m pr\u016fmyslu d\u00edky sv\u00e9 schopnosti zpracov\u00e1vat vysok\u00e9 nap\u011bt\u00ed. Tento \u00fasp\u011bch lze p\u0159i\u010d\u00edst jeho \u0161irok\u00e9mu p\u00e1smov\u00e9mu \u00faseku, kter\u00fd umo\u017e\u0148uje elektron\u016fm snadn\u011bj\u0161\u00ed pr\u016fchod ne\u017e u standardn\u00edch k\u0159em\u00edkov\u00fdch polovodi\u010d\u016f.<\/p>\n
Karbid k\u0159em\u00edku je d\u00edky sv\u00fdm jedine\u010dn\u00fdm vlastnostem vhodn\u00fd pro r\u016fzn\u00e9 elektrick\u00e9 aplikace, v\u010detn\u011b v\u00fdroby energie. Karbid k\u0159em\u00edku si proto z\u00edsk\u00e1v\u00e1 st\u00e1le v\u011bt\u0161\u00ed oblibu v aplikac\u00edch pro elektrick\u00e1 vozidla, kde vytv\u00e1\u0159\u00ed \u00fa\u010dinn\u011bj\u0161\u00ed a v\u00fdkonn\u011bj\u0161\u00ed v\u00fdkonovou elektroniku, kter\u00e1 odol\u00e1v\u00e1 vy\u0161\u0161\u00edmu nap\u011bt\u00ed ne\u017e jej\u00ed k\u0159em\u00edkov\u00e9 ekvivalenty.<\/p>\n
Karbid k\u0159em\u00edku se v p\u0159\u00edrod\u011b nevyskytuje (krom\u011b vz\u00e1cn\u00e9ho miner\u00e1lu zvan\u00e9ho moissanit), p\u0159esto se ji\u017e v\u00edce ne\u017e 100 let masov\u011b vyr\u00e1b\u00ed ve form\u011b pr\u00e1\u0161ku a nyn\u00ed se pou\u017e\u00edv\u00e1 nap\u0159\u00edklad v brusn\u00fdch kotou\u010d\u00edch, brusivech a nepr\u016fst\u0159eln\u00fdch vest\u00e1ch. Mezi jeho vynikaj\u00edc\u00ed vlastnosti pat\u0159\u00ed vysok\u00e1 tvrdost (9 stup\u0148\u016f Mohsovy stupnice), chemick\u00e1 inertnost, tepeln\u00e1 vodivost a odolnost proti ot\u011bru - vlastnosti, d\u00edky nim\u017e je karbid k\u0159em\u00edku \u0161iroce vyhled\u00e1v\u00e1n v\u00fdrobci t\u011bchto aplikac\u00ed.<\/p>\n
Karbid k\u0159em\u00edku tvo\u0159\u00ed dva prim\u00e1rn\u00ed koordina\u010dn\u00ed tetraedry slo\u017een\u00e9 ze \u010dty\u0159 atom\u016f k\u0159em\u00edku a \u010dty\u0159 atom\u016f uhl\u00edku kovalentn\u011b v\u00e1zan\u00fdch kovalentn\u00edmi vazbami, tzv. koordina\u010dn\u00ed tetraedry. Zm\u011bnou uspo\u0159\u00e1d\u00e1n\u00ed atom\u016f lze vytvo\u0159it r\u016fzn\u00e9 polytypy krystalick\u00fdch struktur. P\u0159id\u00e1n\u00edm p\u0159\u00edm\u011bs\u00ed, jako jsou trojmocn\u00e9 nebo p\u011btimocn\u00e9 l\u00e1tky, mohou in\u017een\u00fd\u0159i zm\u011bnit elektrick\u00e9 vlastnosti, aby vyhovovaly r\u016fzn\u00fdm aplikac\u00edm - mezi obl\u00edben\u00e9 dopanty pat\u0159\u00ed b\u00f3r, fosfor a arsen jako dopanty pro karbid k\u0159em\u00edku.<\/p>\n
Tvrd\u00e1 a odoln\u00e1 povaha karbidu k\u0159em\u00edku mu umo\u017e\u0148uje odol\u00e1vat jak vysok\u00fdm teplot\u00e1m, tak opot\u0159eben\u00ed, co\u017e z n\u011bj \u010din\u00ed kl\u00ed\u010dov\u00fd materi\u00e1l pro vyzd\u00edvky pr\u016fmyslov\u00fdch pec\u00ed, sou\u010d\u00e1sti raketov\u00fdch motor\u016f, n\u00e1stroje odoln\u00e9 proti opot\u0159eben\u00ed, jako jsou brusn\u00e9 kotou\u010de a \u010depele n\u00e1stroj\u016f, keramiku, a dokonce i pro v\u00fdrobu polovodi\u010d\u016f dopovan\u00fdch dus\u00edkem, fosforem, hlin\u00edkem nebo heliem, kter\u00e9 se pou\u017e\u00edvaj\u00ed v elektronice, nap\u0159\u00edklad ve sv\u011bteln\u00fdch diod\u00e1ch (LED).<\/p>\n
Karbid k\u0159em\u00edku se v p\u0159\u00edrod\u011b vyskytuje jako miner\u00e1l moissanit. Poprv\u00e9 byl objeven v roce 1893 v meteoritick\u00e9m kr\u00e1teru Canyon Diablo v Arizon\u011b a svou strukturou se podob\u00e1 diamant\u016fm - ve skute\u010dnosti se \u0161perky z moissanitu dlouho prod\u00e1valy jako jejich alternativa.<\/p>\n
Karbid k\u0159em\u00edku je d\u00edky sv\u00fdm brusn\u00fdm vlastnostem ji\u017e dlouho zn\u00e1m\u00fd pro sv\u00e9 pou\u017eit\u00ed v um\u011bleck\u00fdch \u0159emeslech. Pou\u017e\u00edv\u00e1 se k brou\u0161en\u00ed d\u0159eva, kov\u016f a kamen\u016f do hladk\u00fdch povrch\u016f pro malov\u00e1n\u00ed nebo lakov\u00e1n\u00ed; krom\u011b toho je ned\u00edlnou sou\u010d\u00e1st\u00ed modern\u00edho lapid\u00e1ria, kde se pou\u017e\u00edv\u00e1 v mnoha technik\u00e1ch od lept\u00e1n\u00ed skla a\u017e po \u0159ezb\u00e1\u0159stv\u00ed.<\/p>\n
Spole\u010dnost Elkem SiC nab\u00edz\u00ed karbid k\u0159em\u00edku StarCeram S, pr\u016fmyslovou keramiku, kterou lze tvarovat do r\u016fzn\u00fdch tvar\u016f a velikost\u00ed pro specifick\u00e9 aplikace, s jemnou povrchovou \u00fapravou pro \u00fa\u010dely le\u0161t\u011bn\u00ed. N\u00e1\u0161 z\u00e1vod v belgick\u00e9m Liege disponuje modern\u00edm za\u0159\u00edzen\u00edm, kter\u00e9 je schopno vyr\u00e1b\u011bt produkty SiC podle p\u0159esn\u00fdch specifikac\u00ed.<\/p>\n
Karbid k\u0159em\u00edku (SiC), b\u011b\u017en\u011b ozna\u010dovan\u00fd jako karborundum, se p\u0159irozen\u011b vyskytuje jako miner\u00e1l moissanit a od roku 1893 se hromadn\u011b vyr\u00e1b\u00ed jako pr\u00e1\u0161ek pro brusn\u00e9 aplikace, jako jsou brusn\u00e9 kotou\u010de. Od roku 1893 se tak\u00e9 hromadn\u011b sp\u00e9k\u00e1 za vzniku velmi tvrd\u00e9 keramiky, kter\u00e1 se pou\u017e\u00edv\u00e1 v aplikac\u00edch vy\u017eaduj\u00edc\u00edch vysokou odolnost, jako jsou automobilov\u00e9 brzdy, spojky a nepr\u016fst\u0159eln\u00e9 vesty keramick\u00e9 desky osazen\u00e9 deskami SiC osazen\u00fdmi k\u0159em\u00edkem se \u0161irokou p\u00e1smovou mezerou v t\u011bchto kapacit\u00e1ch. D\u00edky \u0161irok\u00e9mu p\u00e1smov\u00e9mu rozp\u011bt\u00ed je SiC v t\u011bchto ohledech lep\u0161\u00ed ne\u017e k\u0159em\u00edk.<\/p>\n
P\u00e1smov\u00e1 propast ozna\u010duje mno\u017estv\u00ed energie pot\u0159ebn\u00e9 k p\u0159echodu elektron\u016f mezi valen\u010dn\u00edmi a vodivostn\u00edmi p\u00e1sy v atomu, d\u00edky \u010demu\u017e se elektrony pohybuj\u00ed rychleji a efektivn\u011bji, co\u017e jsou z\u00e1kladn\u00ed vlastnosti polovodi\u010dov\u00fdch za\u0159\u00edzen\u00ed pracuj\u00edc\u00edch p\u0159i vysok\u00fdch rychlostech a\/nebo nap\u011bt\u00edch. \u0160ir\u0161\u00ed p\u00e1sov\u00e1 mezera umo\u017e\u0148uje elektron\u016fm rychlej\u0161\u00ed pohyb mezi t\u011bmito p\u00e1sy.<\/p>\n
SiC m\u00e1 ve srovn\u00e1n\u00ed s tradi\u010dn\u00edm polovodi\u010dov\u00fdm k\u0159em\u00edkem roz\u0161\u00ed\u0159en\u00fd p\u00e1sov\u00fd rozd\u00edl, co\u017e z n\u011bj \u010din\u00ed ide\u00e1ln\u00ed materi\u00e1l pro v\u00fdkonovou elektroniku, nap\u0159\u00edklad pro trak\u010dn\u00ed m\u011bni\u010de v elektromobilech. Vynikaj\u00edc\u00ed tepeln\u00e1 vodivost SiC oproti k\u0159em\u00edku tuto v\u00fdhodu d\u00e1le zvy\u0161uje a umo\u017e\u0148uje efektivn\u011bj\u0161\u00ed provoz v\u00fdkonov\u00e9 elektroniky bez nutnosti aktivn\u00edch chladic\u00edch syst\u00e9m\u016f, kter\u00e9 zvy\u0161uj\u00ed hmotnost a n\u00e1klady elektromobil\u016f.<\/p>","protected":false},"excerpt":{"rendered":"
Silicon carbide, more commonly referred to by its acronym SiC, is an abrasive material composed of silicon and carbon that has been produced industrially since the late 19th century for use as an abrasive. Furthermore, natural deposits of SiC are present within moissanite mineral formations. Ceramic glazes contain powders of this substance that, when added […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","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":[64],"tags":[],"class_list":["post-200","post","type-post","status-publish","format-standard","hentry","category-knowledge"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/ceramicatijolart.com\/cs\/wp-json\/wp\/v2\/posts\/200","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ceramicatijolart.com\/cs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ceramicatijolart.com\/cs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ceramicatijolart.com\/cs\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ceramicatijolart.com\/cs\/wp-json\/wp\/v2\/comments?post=200"}],"version-history":[{"count":1,"href":"https:\/\/ceramicatijolart.com\/cs\/wp-json\/wp\/v2\/posts\/200\/revisions"}],"predecessor-version":[{"id":201,"href":"https:\/\/ceramicatijolart.com\/cs\/wp-json\/wp\/v2\/posts\/200\/revisions\/201"}],"wp:attachment":[{"href":"https:\/\/ceramicatijolart.com\/cs\/wp-json\/wp\/v2\/media?parent=200"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ceramicatijolart.com\/cs\/wp-json\/wp\/v2\/categories?post=200"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ceramicatijolart.com\/cs\/wp-json\/wp\/v2\/tags?post=200"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}