![\"spekan\u00fd](\"http:\/\/siliconcarbideceramic.net\/wp-content\/uploads\/2024\/04\/sintered-silicon-carbide.jpg\")
<\/p>","protected":false},"excerpt":{"rendered":"Karbid krem\u00edka je jedn\u00fdm z najtvrd\u0161\u00edch keramick\u00fdch materi\u00e1lov, ktor\u00fd sa vyzna\u010duje mimoriadne vysokou pevnos\u0165ou a tepelnou vodivos\u0165ou. Okrem toho je v\u010faka svojej odolnosti vo\u010di oxid\u00e1cii a kor\u00f3zii vhodn\u00fd do prostredia s vysok\u00fdmi teplotami.<\/p>\n
Reak\u010dne sp\u00e1jan\u00fd SiC m\u00e1 hrub\u00e9 zrn\u00e1 a n\u00edzku odolnos\u0165 proti kor\u00f3zii, zatia\u013e \u010do priamo spekan\u00fd SiC je hustej\u0161\u00ed a pon\u00faka lep\u0161\u00ed v\u00fdkon pri vysok\u00fdch teplot\u00e1ch. Pri beztlakovom spekan\u00ed sa pou\u017e\u00edva ve\u013emi jemn\u00fd pr\u00e1\u0161ok SiC s neoxidov\u00fdmi spekan\u00fdmi pr\u00edsadami na v\u00fdrobu hust\u00e9ho materi\u00e1lu s vynikaj\u00facimi fyzik\u00e1lnymi vlastnos\u0165ami.<\/p>\n
Karbid krem\u00edka je jedn\u00fdm z najtvrd\u0161\u00edch be\u017en\u00fdch br\u00fasnych materi\u00e1lov, na Mohsovej stupnici tvrdosti m\u00e1 hodnotu 9,5, \u010do je bl\u00edzko hodnoty 10, ktor\u00fa m\u00e1 diamant. T\u00e1to tvrdos\u0165 mu zaru\u010duje vynikaj\u00facu odolnos\u0165 proti opotrebovaniu aj pri zv\u00fd\u0161en\u00fdch teplot\u00e1ch; chemik\u00e1lie, soli, kyseliny a z\u00e1sady nepredstavuj\u00fa ve\u013ek\u00fa hrozbu; odolnos\u0165 proti tepeln\u00fdm \u0161okom je dobr\u00e1; navy\u0161e jeho hmotnos\u0165 je o polovicu ni\u017e\u0161ia ako hmotnos\u0165 ocele!<\/p>\n
Spekanie v kvapalnej f\u00e1ze m\u00e1 oproti in\u00fdm procesom v\u00fdhody vr\u00e1tane n\u00edzkych tepl\u00f4t spracovania a dobrej tvarovej schopnosti. Okrem toho je v\u010faka svojej plnej hustote a vynikaj\u00facim mechanick\u00fdm vlastnostiam vhodn\u00fd na abraz\u00edvne obr\u00e1banie, br\u00fasenie a le\u0161tenie, ako aj na rezanie, v\u0155tanie, leptanie a fr\u00e9zovanie.<\/p>\n
Spekan\u00fd SiC sa v\u010faka svojej v\u00fdnimo\u010dnej chemickej stabilite, teplotnej odolnosti, n\u00edzkej hustote, pevnosti, odolnosti proti opotrebovaniu a n\u00edzkej aktiva\u010dnej energii \u0161iroko vyu\u017e\u00edva na v\u00fdrobu s\u00fa\u010diastok polovodi\u010dov\u00fdch zariaden\u00ed, laserov a kon\u0161truk\u010dn\u00fdch aplik\u00e1ci\u00ed f\u00faznych reaktorov. K dispoz\u00edcii s\u00fa reak\u010dne sp\u00e1jan\u00e9 aj priamo spekan\u00e9 triedy SiC; reak\u010dne sp\u00e1jan\u00e9 triedy zvy\u010dajne pon\u00fakaj\u00fa ni\u017e\u0161ie n\u00e1klady s hrub\u0161\u00edm zrnom pre ni\u017e\u0161iu n\u00e1razov\u00fa a tepeln\u00fa pr\u00e1cu, zatia\u013e \u010do priamo spekan\u00e9 triedy pon\u00fakaj\u00fa vynikaj\u00facu odolnos\u0165 proti opotrebovaniu pri zv\u00fd\u0161en\u00fdch teplot\u00e1ch s jemnej\u0161\u00edm zrnom, ktor\u00e9 pon\u00faka v\u00e4\u010d\u0161iu odolnos\u0165 proti opotrebovaniu pri zv\u00fd\u0161en\u00fdch teplot\u00e1ch. Triedy s reak\u010dn\u00fdm lepen\u00edm, ktor\u00e9 maj\u00fa hrub\u0161ie zrno s jemnej\u0161\u00edmi zrnami, sa zvy\u010dajne \u0161pecifikuj\u00fa ako \u010dastej\u0161ie pou\u017e\u00edvan\u00e9. Pre v\u00e4\u010d\u0161iu tvrdos\u0165 pri pracovn\u00fdch podmienkach pr\u00e1ce ako vysokoteplotn\u00fdch aplik\u00e1ci\u00e1ch alebo pr\u00e1ci po\u017eadovan\u00fdch ako Priamo spekan\u00e9 typy pou\u017e\u00edvan\u00e9 z d\u00f4vodu vynikaj\u00facej odolnosti proti opotrebeniu pri zv\u00fd\u0161en\u00fdch teplot\u00e1ch \u010dastej\u0161ie \u0161pecifikovan\u00e9 v porovnan\u00ed pre pou\u017eitie, resp. z d\u00f4vodu maj\u00face vynikaj\u00facu odolnos\u0165 proti opotrebeniu pri zv\u00fd\u0161en\u00fdch teplot\u00e1ch s\u00fa po\u017eadovan\u00e9 a tvrdos\u0165 s\u00fa uprednost\u0148ovan\u00e9 pred ke\u010f s\u00fa \u0161pecifikovan\u00e9 ako bu\u010f Odmietnutie m\u00f4\u017ee pou\u017eitie s\u00fa uprednost\u0148ovan\u00e9 z d\u00f4vodu maj\u00face vynikaj\u00facu odolnos\u0165 proti opotrebeniu\/tvrdos\u0165 pri zv\u00fd\u0161en\u00fdch pracovn\u00fdch pr\u00e1cach \u010dastej\u0161ie \u0161pecifikovan\u00e9 priamo Sintrovan\u00e9 typy ke\u010f s\u00fa \u0161pecifikovan\u00e9 s priamo spekan\u00fdmi triedami m\u00f4\u017eu potrebova\u0165 obe mo\u017enosti s\u00fa \u0161pecifikovan\u00e9 a tvrdos\u0165 poskytuje \u010dastej\u0161ie pou\u017e\u00edvan\u00e9 tak.<\/p>\n
Karbid krem\u00edka je mimoriadne pevn\u00fd \u017eiaruvzdorn\u00fd keramick\u00fd materi\u00e1l s vynikaj\u00facou tvrdos\u0165ou, pevnos\u0165ou pri vysok\u00fdch teplot\u00e1ch a odolnos\u0165ou proti chemickej kor\u00f3zii - vlastnosti, ktor\u00e9 z neho robia jeden z najuniverz\u00e1lnej\u0161\u00edch \u017eiaruvzdorn\u00fdch materi\u00e1lov na svete, ktor\u00fd sa vyu\u017e\u00edva v r\u00f4znych priemyseln\u00fdch aplik\u00e1ci\u00e1ch.<\/p>\n
Spekanie lisovan\u00edm za tepla je jednou zo z\u00e1kladn\u00fdch met\u00f3d v\u00fdroby keramiky SiC. Pri tejto technike sa vyu\u017e\u00edva extr\u00e9mne jemn\u00fd pr\u00e1\u0161ok karbidu krem\u00edka zmie\u0161an\u00fd so spekan\u00fdmi pr\u00edsadami, ktor\u00fd sa zhut\u0148uje tradi\u010dn\u00fdmi met\u00f3dami tvarovania keramiky, ako je izostatick\u00fd lis, lisovanie pod tlakom alebo vstrekovanie, aby sa vytvorili hust\u00e9 \u0161trukt\u00fary pozost\u00e1vaj\u00face z drobn\u00fdch \u010dast\u00edc, ktor\u00e9 zabezpe\u010duj\u00fa pevnos\u0165.<\/p>\n
Beztlakov\u00e9 spekanie SiC v kvapalnej f\u00e1ze (LPPSiC) je \u010fal\u0161ou technikou zhut\u0148ovania SiC. V tomto pr\u00edpade sa do zelen\u00e9ho telesa z \u010dast\u00edc a-SiC zav\u00e1dza tekut\u00fd krem\u00edk alebo zliatina krem\u00edka, \u010d\u00edm sa vytvor\u00ed b-SiC, ktor\u00fd reaguje a sp\u00e1ja sa s existuj\u00facimi \u010dasticami a-SiC, \u010d\u00edm sa zhutn\u00ed a zhust\u00ed teleso ako celok.<\/p>\n
Reak\u010dne spekan\u00fd karbid krem\u00edka m\u00e1 vynikaj\u00facu tvarov\u00fa schopnos\u0165 pre zlo\u017eit\u00e9 tvary, n\u00edzke teploty spracovania a \u00farovne \u010distoty; jeho mechanick\u00e9 vlastnosti, ako napr\u00edklad pevnos\u0165 v ohybe, s\u00fa ni\u017e\u0161ie ako u be\u017ene spekan\u00e9ho karbidu krem\u00edka; na zv\u00fd\u0161enie tejto vlastnosti je potrebn\u00e9 kontrolova\u0165 ve\u013ekos\u0165 zvy\u0161kov\u00e9ho Si regul\u00e1ciou ve\u013ekosti \u010dast\u00edc pod 100 nm - tento \u00faspech znamen\u00e1 ve\u013ek\u00fd \u00faspech pri zvy\u0161ovan\u00ed pevnosti keramiky LSiC.<\/p>\n
Karbid krem\u00edka sa vyzna\u010duje vynikaj\u00facou odolnos\u0165ou proti kor\u00f3zii a odol\u00e1va teplot\u00e1m a\u017e do 1900 \u00b0C, tak\u017ee je vhodn\u00fd na aplik\u00e1cie, kde by chemick\u00e9 a tepeln\u00e9 \u0161oky mohli po\u0161kodi\u0165 komponenty.<\/p>\n
Kor\u00f3zia v keramike vznik\u00e1 v d\u00f4sledku tvorby vrstvy oxidu na jej povrchu, zvy\u010dajne oxidu kremi\u010dit\u00e9ho alebo kremi\u010ditanov\u00e9ho, v z\u00e1vislosti od faktorov, ako s\u00fa vplyv prostredia, ne\u010distoty, pomocn\u00e9 l\u00e1tky pri spekan\u00ed, f\u00e1zy na hranici z\u0155n a reakcie, ktor\u00e9 nastali kr\u00e1tko po nich. To vedie k ve\u013ek\u00fdm rozdielom v kor\u00f3znom spr\u00e1van\u00ed materi\u00e1lov z karbidu krem\u00edka a nitridu krem\u00edka.<\/p>\n
Ke\u010f\u017ee pri navrhovan\u00ed materi\u00e1lov na pou\u017eitie v koroz\u00edvnom prostred\u00ed sa v prvom rade zoh\u013ead\u0148uje miera pre\u017eitia (meran\u00e1 ako miera \u00fastupu v koroz\u00edvnom prostred\u00ed) a mechanick\u00e1 pevnos\u0165 (pevnos\u0165 v C-kr\u00fa\u017eku alebo pevnos\u0165 v \u0161tvorbodovom ohybe), kor\u00f3zia zvy\u0161uje povrchov\u00e9 chyby, ktor\u00e9 \u010dasom oslabuj\u00fa ich pevnos\u0165 a zni\u017euj\u00fa ich mechanick\u00fa \u017eivotnos\u0165.<\/p>\n
Spekan\u00fd karbid krem\u00edka je vynikaj\u00facou vo\u013ebou na pou\u017eitie v n\u00e1ro\u010dn\u00fdch podmienkach v\u010faka kombin\u00e1cii vysokej pevnosti a odolnosti proti opotrebovaniu, n\u00edzkej \u0161pecifickej hustote a vynikaj\u00facim tribologick\u00fdm vlastnostiam. \u010casto sa pou\u017e\u00edva v s\u00fa\u010diastkach, ktor\u00e9 musia odol\u00e1va\u0165 n\u00e1razov\u00e9mu za\u0165a\u017eeniu od \u0165a\u017ek\u00fdch bremien, ako s\u00fa trysky na otrysk\u00e1vanie alebo lo\u017eisk\u00e1 pre klzn\u00e9 lo\u017eisk\u00e1; okrem toho sa vo ve\u013ekej miere vyu\u017e\u00edva pri v\u00fdrobe b\u0155zd vystu\u017een\u00fdch karbidom krem\u00edka s uhl\u00edkov\u00fdmi vl\u00e1knami alebo pri v\u00fdrobe nepriestreln\u00fdch pancierov, preto\u017ee je odoln\u00fd vo\u010di vysok\u00fdm nam\u00e1haniam a teplot\u00e1m.<\/p>\n
Spekan\u00fd karbid krem\u00edka je extr\u00e9mne tvrd\u00fd keramick\u00fd materi\u00e1l s vynikaj\u00facou odolnos\u0165ou proti opotrebovaniu a ochranou proti kor\u00f3zii, \u010do z neho rob\u00ed vynikaj\u00faci br\u00fasny materi\u00e1l. Mo\u017eno ho n\u00e1js\u0165 v br\u00fasnych kot\u00fa\u010doch, kame\u0148och na honovanie, pieskova\u010doch a fr\u00e9zach na br\u00fasenie alebo honovanie, ako aj v procesoch rezania vodn\u00fdm l\u00fa\u010dom.<\/p>\n
Chemick\u00e1 odolnos\u0165 tohto materi\u00e1lu mu umo\u017e\u0148uje odol\u00e1va\u0165 dlhodob\u00e9mu p\u00f4sobeniu be\u017en\u00fdch anorganick\u00fdch kysel\u00edn, sol\u00ed a l\u00fahov bez toho, aby do\u0161lo k jeho degrad\u00e1cii. Okrem toho sa jeho odolnos\u0165 zvy\u0161uje v\u010faka tesne ulo\u017een\u00fdm kovalentn\u00fdm v\u00e4zb\u00e1m vytvoren\u00fdm zo 4 at\u00f3mov krem\u00edka a 4 at\u00f3mov uhl\u00edka pri tvorbe tetraedrick\u00fdch koordin\u00e1ci\u00ed.<\/p>\n
Spekan\u00fd SiC sa vytv\u00e1ra lisovan\u00edm a spekan\u00edm (zahrievan\u00edm) \u010dast\u00edc pr\u00e1\u0161kov\u00e9ho oxidu kremi\u010dit\u00e9ho. Spekanie umo\u017e\u0148uje, aby sa tieto jednotliv\u00e9 \u010dastice spojili do pevn\u00e9ho celku s vysokou tvrdos\u0165ou a pevnos\u0165ou, ktor\u00fd je z\u00e1rove\u0148 odoln\u00fd vo\u010di oxid\u00e1cii a kor\u00f3zii; okrem toho m\u00e1 v\u00e4\u010d\u0161iu trvanlivos\u0165 ako v\u00e4\u010d\u0161ina typov keramiky.<\/p>\n
Reak\u010dne viazan\u00fd karbid krem\u00edka, vyr\u00e1ban\u00fd infiltr\u00e1ciou tekut\u00e9ho krem\u00edka do por\u00e9znych grafitov\u00fdch alebo uhl\u00edkov\u00fdch predliskov, m\u00e1 ni\u017e\u0161iu pevnos\u0165 ako spekan\u00fd karbid krem\u00edka, ale je vhodnej\u0161\u00ed v\u010faka n\u00edzkym teplot\u00e1m spracovania, dobrej tvarovate\u013enosti a vy\u0161\u0161ej \u010distote. Komer\u010dne dostupn\u00fd reak\u010dne spekan\u00fd karbid krem\u00edka m\u00e1 pri izbovej teplote pevnos\u0165 v ohybe pribli\u017ene 300 MPa.<\/p>\n
Reak\u010dne spekan\u00fd karbid krem\u00edka s b\u00f3rov\u00fdmi alebo uhl\u00edkov\u00fdmi spekan\u00fdmi pomocn\u00fdmi l\u00e1tkami m\u00e1 extr\u00e9mne vysok\u00fa odolnos\u0165 proti te\u010deniu, ktor\u00e1 sa dosahuje \u00fapravou energi\u00ed na hraniciach z\u0155n a povrchov\u00fdch energi\u00ed, ako aj zv\u00fd\u0161en\u00edm objemovej dif\u00fazie na podporu zhut\u0148ovania a zhut\u0148ovania. To umo\u017e\u0148uje, aby zrn\u00e1 zostali v priamom kry\u0161talickom kontakte bez vytv\u00e1rania \u0161trukt\u00far druhej f\u00e1zy na hraniciach z\u0155n.<\/p>\n
<\/p>","protected":false},"excerpt":{"rendered":"
Silicon carbide is one of the hardest ceramic materials, boasting extremely high strength and thermal conductivity. Additionally, its resistance to […]<\/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":"default","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":"default","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","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":[5],"tags":[],"class_list":["post-86","post","type-post","status-publish","format-standard","hentry","category-product-related"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/siliconcarbideceramic.net\/sk\/wp-json\/wp\/v2\/posts\/86","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/siliconcarbideceramic.net\/sk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/siliconcarbideceramic.net\/sk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/sk\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/sk\/wp-json\/wp\/v2\/comments?post=86"}],"version-history":[{"count":4,"href":"https:\/\/siliconcarbideceramic.net\/sk\/wp-json\/wp\/v2\/posts\/86\/revisions"}],"predecessor-version":[{"id":380,"href":"https:\/\/siliconcarbideceramic.net\/sk\/wp-json\/wp\/v2\/posts\/86\/revisions\/380"}],"wp:attachment":[{"href":"https:\/\/siliconcarbideceramic.net\/sk\/wp-json\/wp\/v2\/media?parent=86"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/sk\/wp-json\/wp\/v2\/categories?post=86"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/sk\/wp-json\/wp\/v2\/tags?post=86"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}