Karbid k\u0159em\u00edku je jedn\u00edm z nejtvrd\u0161\u00edch a nejpevn\u011bj\u0161\u00edch materi\u00e1l\u016f na Zemi, kter\u00fd je zn\u00e1m\u00fd svou pevnost\u00ed, tepelnou vodivost\u00ed a odolnost\u00ed v\u016f\u010di kyselin\u00e1m, co\u017e jsou vlastnosti, d\u00edky nim\u017e je vhodn\u00fd pro pou\u017eit\u00ed v r\u016fzn\u00fdch pr\u016fmyslov\u00fdch odv\u011btv\u00edch.<\/p>\n
SiC je p\u0159irozen\u011b se vyskytuj\u00edc\u00ed miner\u00e1l zn\u00e1m\u00fd jako moissanit; od roku 1893 se v\u0161ak masov\u011b vyr\u00e1b\u00ed ve form\u011b pr\u00e1\u0161ku a krystal\u016f pro pou\u017eit\u00ed jako brusivo a pro dal\u0161\u00ed pr\u016fmyslov\u00e9 a polovodi\u010dov\u00e9 substr\u00e1ty.<\/p>\n
Karbid k\u0159em\u00edku m\u00e1 jedine\u010dn\u00e9 vlastnosti, kter\u00e9 z n\u011bj \u010din\u00ed jeden z nejv\u00fdhodn\u011bj\u0161\u00edch pr\u016fmyslov\u00fdch materi\u00e1l\u016f. Mezi pokro\u010dil\u00fdmi keramick\u00fdmi materi\u00e1ly je zejm\u00e9na tvrd\u00fd a lehk\u00fd; d\u00e1le se m\u016f\u017ee pochlubit vynikaj\u00edc\u00ed tepelnou vodivost\u00ed s n\u00edzkou tepelnou rozta\u017enost\u00ed; nav\u00edc snadno zvl\u00e1d\u00e1 erozi a ot\u011br - tyto vlastnosti jej p\u0159edur\u010duj\u00ed k pou\u017eit\u00ed v syst\u00e9mech oblo\u017een\u00ed ml\u00fdn\u016f, sou\u010d\u00e1stech cyklon\u016f, trysk\u00e1ch post\u0159ikova\u010d\u016f a extrud\u00e9r\u016f.<\/p>\n
Karbid k\u0159em\u00edku je v \u010dist\u00e9m stavu elektrick\u00fd izolant. P\u0159id\u00e1n\u00edm \u0159\u00edzen\u00fdch p\u0159\u00edm\u011bs\u00ed v\u0161ak lze karbid k\u0159em\u00edku p\u0159im\u011bt, aby se choval jako polovodi\u010d - hlin\u00edk, b\u00f3r a galium mohou vytvo\u0159it za\u0159\u00edzen\u00ed typu P, zat\u00edmco dus\u00edk a fosfor d\u00e1vaj\u00ed vzniknout za\u0159\u00edzen\u00edm typu N.<\/p>\n
Tranzistory SiC se ve srovn\u00e1n\u00ed se sv\u00fdmi k\u0159em\u00edkov\u00fdmi prot\u011bj\u0161ky vyzna\u010duj\u00ed vy\u0161\u0161\u00edm pr\u016frazn\u00fdm nap\u011bt\u00edm a ni\u017e\u0161\u00edm zap\u00ednac\u00edm odporem, co\u017e umo\u017e\u0148uje vy\u0161\u0161\u00ed sp\u00ednac\u00ed frekvence a men\u0161\u00ed syst\u00e9my v\u00fdkonov\u00e9 elektroniky. St\u0159\u00edda\u010de pro nab\u00edjen\u00ed elektromobil\u016f mohou vyu\u017e\u00edvat SiC ke sn\u00ed\u017een\u00ed velikosti a hmotnosti sv\u00fdch syst\u00e9m\u016f \u0159\u00edzen\u00ed nap\u00e1jen\u00ed a ke zv\u00fd\u0161en\u00ed dojezdu.<\/p>\n
Karbid k\u0159em\u00edku, \u010dast\u011bji ozna\u010dovan\u00fd jako SiC, je mimo\u0159\u00e1dn\u011b tvrd\u00e1, synteticky vyr\u00e1b\u011bn\u00e1 krystalick\u00e1 slou\u010denina slo\u017een\u00e1 z k\u0159em\u00edku a uhl\u00edku, kter\u00e1 je chemicky inertn\u00ed a odoln\u00e1 proti korozi (i kdy\u017e n\u00e1chyln\u00e1 k p\u016fsoben\u00ed kyseliny chlorovod\u00edkov\u00e9, s\u00edrov\u00e9 nebo jin\u00fdch kyselin).<\/p>\n
Karbid k\u0159em\u00edku se m\u016f\u017ee pochlubit mnoha v\u00fdhodn\u00fdmi vlastnostmi, kter\u00e9 z n\u011bj \u010din\u00ed cenn\u00fd materi\u00e1l, v\u010detn\u011b vysok\u00e9 pevnosti a tuhosti, n\u00edzk\u00e9 tepeln\u00e9 rozta\u017enosti, odolnosti proti oxidaci a ot\u011bru a zachov\u00e1n\u00ed pru\u017enosti i p\u0159i vysok\u00fdch teplot\u00e1ch. D\u00edky t\u00e9to kombinaci keramick\u00fdch a polovodi\u010dov\u00fdch vlastnost\u00ed je vynikaj\u00edc\u00ed volbou materi\u00e1lu pro konstruk\u010dn\u00ed keramiku i abraziva.<\/p>\n
\u010cist\u00fd SiC je bezbarv\u00fd krystal. P\u0159id\u00e1n\u00edm r\u016fzn\u00e9ho mno\u017estv\u00ed p\u0159\u00edm\u011bs\u00ed v\u0161ak lze jeho elektrick\u00e9 vlastnosti zm\u011bnit na polovodi\u010d. Vrstevnat\u00e9 struktury uvnit\u0159 krystal\u016f vytv\u00e1\u0159ej\u00ed r\u016fzn\u00e9 polytypy karbidu k\u0159em\u00edku s jedine\u010dnou krystalovou strukturou; nej\u010dast\u011bji se vyskytuje hexagon\u00e1ln\u00ed krystalov\u00e1 struktura 6H-SiC vhodn\u00e1 pro v\u00fdkonovou elektroniku d\u00edky \u0161irok\u00e9 hodnot\u011b p\u00e1smov\u00e9 mezery 1,12eV podle spole\u010dnosti Wolfspeed.<\/p>\n
Jedine\u010dn\u00e9 fyzik\u00e1ln\u00ed a elektronick\u00e9 vlastnosti karbidu k\u0159em\u00edku p\u0159in\u00e1\u0161ej\u00ed revoluci do v\u00fdkonov\u00e9 elektroniky. Nov\u00e1 za\u0159\u00edzen\u00ed vyroben\u00e1 s pou\u017eit\u00edm SiC se ve srovn\u00e1n\u00ed se sv\u00fdmi p\u0159edch\u016fdci vyzna\u010duj\u00ed vy\u0161\u0161\u00ed spolehlivost\u00ed, ni\u017e\u0161\u00edmi ztr\u00e1tami energie, rychlej\u0161\u00edmi sp\u00ednac\u00edmi \u010dasy a vy\u0161\u0161\u00ed energetickou \u00fa\u010dinnost\u00ed.<\/p>\n
\u010cist\u00fd karbid k\u0159em\u00edku se chov\u00e1 jako elektrick\u00fd izolant, av\u0161ak jeho dopov\u00e1n\u00ed \u0159\u00edzen\u00fdmi p\u0159\u00edm\u011bsemi (tzv. dopanty) mu za ur\u010dit\u00fdch okolnost\u00ed umo\u017e\u0148uje v\u00e9st elektrick\u00fd proud. Dopov\u00e1n\u00ed hlin\u00edkem, borem a heliem vytv\u00e1\u0159\u00ed polovodi\u010de typu P; dopov\u00e1n\u00ed fosforem a dus\u00edkem vytv\u00e1\u0159\u00ed polovodi\u010de typu N.<\/p>\n
Atomov\u00e1 struktura karbidu k\u0159em\u00edku se podob\u00e1 atom\u016fm uhl\u00edku a k\u0159em\u00edku kovalentn\u011b v\u00e1zan\u00fdm do dvou prim\u00e1rn\u00edch koordina\u010dn\u00edch tetraedr\u016f, p\u0159i\u010dem\u017e \u010dty\u0159i atomy uhl\u00edku a \u010dty\u0159i atomy k\u0159em\u00edku se vz\u00e1jemn\u011b kovalentn\u011b v\u00e1\u017eou a vytv\u00e1\u0159ej\u00ed dva prim\u00e1rn\u00ed koordina\u010dn\u00ed tetraedry - ka\u017ed\u00fd se skl\u00e1d\u00e1 ze \u010dty\u0159 atom\u016f uhl\u00edku a \u010dty\u0159 atom\u016f k\u0159em\u00edku vz\u00e1jemn\u011b kovalentn\u011b v\u00e1zan\u00fdch kovalentn\u00edmi vazbami. Lze jej p\u011bstovat do r\u016fzn\u00fdch tvar\u016f; obvykle se rozemele na jemn\u00fd pr\u00e1\u0161ek a pot\u00e9 sm\u00edch\u00e1 s neoxidov\u00fdmi sp\u00e9kac\u00edmi prost\u0159edky, jako jsou organok\u0159emi\u010dit\u00e1 pojiva, za vzniku pastovit\u00e9 sm\u011bsi, kterou lze n\u00e1sledn\u011b tvarovat pomoc\u00ed izostatick\u00e9ho lisov\u00e1n\u00ed za studena nebo vytla\u010dov\u00e1n\u00ed - hojn\u011b se pou\u017e\u00edv\u00e1 v \u0159ezn\u00fdch n\u00e1stroj\u00edch, konstruk\u010dn\u00edch materi\u00e1lech (nepr\u016fst\u0159eln\u00e9 vesty\/kompozitn\u00ed panc\u00ed\u0159e), p\u0159i v\u00fdrob\u011b automobilov\u00fdch d\u00edl\u016f, p\u0159i v\u00fdrob\u011b zrcadlov\u00fdch materi\u00e1l\u016f a tak\u00e9 jako materi\u00e1l pro zrcadla astronomick\u00fdch dalekohled\u016f.<\/p>\n
Karbid k\u0159em\u00edku je jedn\u00edm z nejtvrd\u0161\u00edch a nejpevn\u011bj\u0161\u00edch pokro\u010dil\u00fdch keramick\u00fdch materi\u00e1l\u016f, kter\u00fd se vyzna\u010duje n\u00edzkou tepelnou rozta\u017enost\u00ed, odolnost\u00ed proti kyselin\u00e1m, erozi a vynikaj\u00edc\u00ed odolnost\u00ed proti opot\u0159eben\u00ed.<\/p>\n
V\u00fdroba karbidu k\u0159em\u00edku zahrnuje r\u016fzn\u00e9 chemick\u00e9 reakce, ale nej\u010dast\u011bji se pou\u017e\u00edv\u00e1 Acheson\u016fv proces. Ten zahrnuje zah\u0159\u00edv\u00e1n\u00ed sm\u011bsi oxidu k\u0159emi\u010dit\u00e9ho a koksu p\u0159i vysok\u00fdch teplot\u00e1ch, dokud jejich chemick\u00e9 l\u00e1tky chemicky nezreaguj\u00ed a nevytvo\u0159\u00ed krystaly.<\/p>\n
Tyto krystaly se pak rozemelou na jemn\u00fd pr\u00e1\u0161ek a v kombinaci s neoxidov\u00fdmi sp\u00e9kac\u00edmi prost\u0159edky, jako jsou organok\u0159emi\u010dit\u00e1 pojiva, se vytvo\u0159\u00ed pasta, kter\u00e1 se zhutn\u00ed a vytvaruje vytla\u010dov\u00e1n\u00edm nebo izostatick\u00fdm lisov\u00e1n\u00edm za studena.<\/p>\n
Karbid k\u0159em\u00edku je d\u00edky sv\u00e9 tvrdosti a odolnosti nepostradateln\u00fdm materi\u00e1lem v modern\u00edm lapid\u00e1riu. D\u00edky sv\u00e9 v\u0161estrannosti se pou\u017e\u00edv\u00e1 pro v\u00fdrobu v\u0161eho mo\u017en\u00e9ho, od vyzd\u00edvek pec\u00ed, \u0159ezn\u00fdch n\u00e1stroj\u016f a brusn\u00fdch kotou\u010d\u016f, p\u0159es sou\u010d\u00e1sti odoln\u00e9 proti opot\u0159eben\u00ed v \u010derpadlech a raketov\u00fdch motorech, sou\u010d\u00e1stky v\u00fdkonov\u00e9 elektroniky s n\u00edzk\u00fdm odporem a\u017e po ten\u010d\u00ed desti\u010dky d\u00edky ni\u017e\u0161\u00edmu pr\u016frazn\u00e9mu nap\u011bt\u00ed.<\/p>","protected":false},"excerpt":{"rendered":"
Silicon carbide is one of the hardest and strongest materials on Earth, known for its strength, thermal conductivity and acid resistance – qualities which make it suitable for applications across industries. SiC is a naturally-occurring mineral known as moissanite; however, since 1893 it has been mass produced as powder and crystal form for use as […]<\/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-112","post","type-post","status-publish","format-standard","hentry","category-knowledge"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/ceramicatijolart.com\/cs\/wp-json\/wp\/v2\/posts\/112","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=112"}],"version-history":[{"count":1,"href":"https:\/\/ceramicatijolart.com\/cs\/wp-json\/wp\/v2\/posts\/112\/revisions"}],"predecessor-version":[{"id":113,"href":"https:\/\/ceramicatijolart.com\/cs\/wp-json\/wp\/v2\/posts\/112\/revisions\/113"}],"wp:attachment":[{"href":"https:\/\/ceramicatijolart.com\/cs\/wp-json\/wp\/v2\/media?parent=112"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ceramicatijolart.com\/cs\/wp-json\/wp\/v2\/categories?post=112"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ceramicatijolart.com\/cs\/wp-json\/wp\/v2\/tags?post=112"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}