Karbid krem\u00edka vykazuje ve\u013emi vysok\u00fa pevnos\u0165 pri zv\u00fd\u0161en\u00fdch teplot\u00e1ch, ako aj ve\u013ek\u00fa tvrdos\u0165, odolnos\u0165 proti kor\u00f3zii, odolnos\u0165 proti tepeln\u00fdm \u0161okom a toleranciu vo\u010di tepeln\u00fdm \u0161okom.<\/p>\n
Reak\u010dne viazan\u00fd karbid krem\u00edka (RBSiC) sa vyr\u00e1ba infiltr\u00e1ciou tekut\u00e9ho krem\u00edka do por\u00e9znych uhl\u00edkov\u00fdch alebo grafitov\u00fdch predliskov s presn\u00fdmi rozmermi. T\u00fdmto procesom sa z\u00edskavaj\u00fa v\u00fdrobky s vysokou hustotou a presn\u00fdmi rozmermi.<\/p>\n
Karbid krem\u00edka alebo SiC je nezni\u010dite\u013en\u00fd keramick\u00fd materi\u00e1l, ktor\u00fd je schopn\u00fd odol\u00e1va\u0165 vysok\u00fdm teplot\u00e1m, chemickej kor\u00f3zii a mechanick\u00e9mu opotrebovaniu. Ako jedno z naj\u010dastej\u0161ie pou\u017e\u00edvan\u00fdch br\u00fasnych z\u0155n s priemernou tvrdos\u0165ou pod\u013ea Mohsa 9 porovnate\u013enou s diamantom sa SSiC m\u00f4\u017ee pochv\u00e1li\u0165 vynikaj\u00facou odolnos\u0165ou proti er\u00f3zii a tepelnou stabilitou - ide\u00e1lnym rie\u0161en\u00edm pre aplik\u00e1cie vy\u017eaduj\u00face vysok\u00fa r\u00fdchlos\u0165 a tolerancie pri obr\u00e1ban\u00ed.<\/p>\n
Spekan\u00fd a reak\u010dne viazan\u00fd karbid krem\u00edka s\u00fa dve z\u00e1kladn\u00e9 formy karbidu krem\u00edka. Reak\u010dne viazan\u00e9 druhy s\u00fa zvy\u010dajne hustej\u0161ie, ale maj\u00fa ni\u017e\u0161iu \u0165a\u017enos\u0165 a pevnos\u0165; v\u00fdroba zah\u0155\u0148a infiltr\u00e1ciu por\u00e9znych kovov\u00fdch alebo keramick\u00fdch telies tekut\u00fdm krem\u00edkom, aby reagoval s pr\u00edtomn\u00fdmi molekulami uhl\u00edka, vyplnil p\u00f3ry a potom sa spekan\u00edm vytvorila hust\u00e1 pevn\u00e1 hmota.<\/p>\n
Spekan\u00fd karbid krem\u00edka (SSiC) sa vyr\u00e1ba lisovan\u00edm a spekan\u00edm pr\u00e1\u0161kov\u00e9ho a-SiC so spekan\u00fdmi pr\u00edsadami do pevn\u00e9ho kusu materi\u00e1lu, zvy\u010dajne pre aplik\u00e1cie vy\u017eaduj\u00face vysok\u00fa \u00farove\u0148 pevnosti a tvrdosti. SSiC sa dod\u00e1va v r\u00f4znych tvaroch a ve\u013ekostiach, aby sp\u013a\u0148al po\u017eiadavky r\u00f4znych priemyseln\u00fdch odvetv\u00ed.<\/p>\n
Spekanie je termochemick\u00e1 reakcia, pri ktorej sa \u010dastice pr\u00e1\u0161ku sp\u00e1jaj\u00fa do jedn\u00e9ho pevn\u00e9ho kusu materi\u00e1lu, \u010d\u00edm vznik\u00e1 jeden rovnomern\u00fd kus pri relat\u00edvne n\u00edzkych teplot\u00e1ch a kr\u00e1tkom \u010dase spekania. V\u010faka tomu je SSiC ekonomick\u00fd materi\u00e1l s lep\u0161\u00edmi mechanick\u00fdmi vlastnos\u0165ami a chemickou odolnos\u0165ou ako pri v\u00fdrobn\u00fdch procesoch \u010dist\u00e9ho CVD a-SiC.<\/p>\n
Karbid krem\u00edka vykazuje vynikaj\u00facu chemick\u00fa odolnos\u0165 vo\u010di agres\u00edvnym prostrediam, ako s\u00fa kyseliny chlorovod\u00edkov\u00e1 a s\u00edrov\u00e1. Okrem toho jeho jedine\u010dn\u00e1 \u0161trukt\u00fara vytv\u00e1ra ochrann\u00fa povrchov\u00fa vrstvu, ktor\u00e1 poskytuje maxim\u00e1lnu ochranu. To vysvet\u013euje jeho vysok\u00fd v\u00fdkon vo\u010di z\u00e1sad\u00e1m (napr. pota\u0161 a kaustick\u00e1 s\u00f3da), ako aj vo\u010di oxida\u010dn\u00fdm kyselin\u00e1m, ako je kyselina dusi\u010dn\u00e1. T\u00fato odolnos\u0165 mo\u017eno prip\u00edsa\u0165 jeho prirodzen\u00fdm vlastnostiam; ktor\u00e9 vytv\u00e1raj\u00fa na jeho povrchu pasiva\u010dn\u00fa vrstvu.<\/p>\n
T\u00e1to vrstva zabra\u0148uje priamemu kontaktu medzi substr\u00e1tom a \u00fato\u010diacimi l\u00e1tkami a dif\u00fazii kysl\u00edka cez \u0148u, \u010d\u00edm sa v\u00fdrazne zni\u017euje r\u00fdchlos\u0165 kor\u00f3zie. Jej zlo\u017eenie a hr\u00fabka z\u00e1visia od faktorov, ako je materi\u00e1l pou\u017eit\u00fd pri jej kon\u0161trukcii, ako aj teplota vystavenia alebo bezprostredn\u00e9 chemick\u00e9 prostredie, v ktorom sa komponenty nach\u00e1dzaj\u00fa.<\/p>\n
Reak\u010dne viazan\u00fd karbid krem\u00edka (RB SiC) prekon\u00e1va konven\u010dn\u00fd spekan\u00fd karbid krem\u00edka (SSiC). RB SiC, vyr\u00e1ban\u00fd infiltr\u00e1ciou tekut\u00e9ho krem\u00edka do por\u00e9znych uhl\u00edkov\u00fdch alebo grafitov\u00fdch predliskov, pon\u00faka vynikaj\u00facu tvrdos\u0165 a pevnos\u0165, ako aj dobr\u00fa odolnos\u0165 vo\u010di tepeln\u00fdm \u0161okom a kor\u00f3zii.<\/p>\n
Okrem toho RB SiC vykazuje v\u00fdnimo\u010dn\u00e9 pevnosti v tlaku, \u0165ahu a ohybe v\u010faka svojej vysoko hustej mikro\u0161trukt\u00fare a n\u00edzkej teplote spracovania dosiahnutej reak\u010dn\u00fdm spekan\u00edm. Okrem toho sa jeho pevnos\u0165 v ohybe zvy\u0161ovala s klesaj\u00facou ve\u013ekos\u0165ou zvy\u0161kov\u00e9ho krem\u00edka; pri kontrole ve\u013ekosti krem\u00edkov\u00fdch \u010dast\u00edc pod 100 nm pre optim\u00e1lne v\u00fdsledky sk\u00fa\u0161ok sa dosiahlo viac ako 1000 MPa.<\/p>\n
Karbid krem\u00edka (SiC) je jedn\u00fdm z najtvrd\u0161\u00edch keramick\u00fdch materi\u00e1lov, ktor\u00fd sa vyzna\u010duje vynikaj\u00facou odolnos\u0165ou proti opotrebovaniu, teplotnou stabilitou a tepelnou vodivos\u0165ou. Okrem toho je SiC v\u010faka svojej odolnosti vo\u010di kor\u00f3zii a tepeln\u00fdm \u0161okom bezkonkuren\u010dn\u00fd v porovnan\u00ed s ak\u00fdmko\u013evek in\u00fdm materi\u00e1lom na trhu. Vyr\u00e1ba sa met\u00f3dou reak\u010dn\u00e9ho sp\u00e1jania alebo priameho spekania; reak\u010dne sp\u00e1jan\u00fd SiC pon\u00faka ni\u017e\u0161iu tvrdos\u0165, ale je cenovo v\u00fdhodnej\u0161\u00ed a \u013eah\u0161ie sa s n\u00edm pracuje ako s jeho priamo spekan\u00fdm n\u00e1protivkom.<\/p>\n
Tepeln\u00e1 vodivos\u0165 SiC do zna\u010dnej miery z\u00e1vis\u00ed od sp\u00f4sobu spekania a pou\u017eitia pr\u00edsad. Napr\u00edklad SiC spekan\u00fd s 9 hmotnostn\u00fdmi % Y2O3-Er2O3 vykazuje ove\u013ea ni\u017e\u0161\u00ed elektrick\u00fd odpor v porovnan\u00ed so vzorkami bez tejto pr\u00edsady; je to pravdepodobne sp\u00f4soben\u00e9 ve\u013ek\u00fdm po\u010dtom vakanci\u00ed a kry\u0161talografick\u00fdch defektov pr\u00edtomn\u00fdch v jeho f\u00e1ze, ktor\u00e9 zni\u017euj\u00fa tepeln\u00fa vodivos\u0165.<\/p>\n
Spek\u00e1rske pr\u00edsady sa prid\u00e1vaj\u00fa do SiC pr\u00e1\u0161ku pred spekan\u00edm s cie\u013eom zv\u00fd\u0161i\u0165 hustotu hotov\u00e9ho v\u00fdrobku, a t\u00fdm zv\u00fd\u0161i\u0165 jeho hustotu. Nane\u0161\u0165astie v\u0161ak ich prid\u00e1vanie m\u00f4\u017ee zv\u00fd\u0161i\u0165 teplotu spekania a zn\u00ed\u017ei\u0165 pevnos\u0165 v ohybe; v d\u00f4sledku toho je nevyhnutn\u00e9 n\u00e1js\u0165 rovnov\u00e1hu medzi tepelnou vodivos\u0165ou a pevnos\u0165ou v ohybe SiC keramiky. To sa d\u00e1 dosiahnu\u0165 v\u00fdberom vhodn\u00fdch spek\u00e1rskych pr\u00edsad a zodpovedaj\u00facim prisp\u00f4soben\u00edm procesu spekania; okrem toho \u010dist\u00e9 hranice z\u0155n pom\u00e1haj\u00fa zvy\u0161ova\u0165 tepeln\u00fa vodivos\u0165, preto\u017ee pom\u00e1haj\u00fa zni\u017eova\u0165 tepeln\u00e9 straty medzi zrnami a dutinami, \u010d\u00edm sa zvy\u0161uje tepeln\u00e1 vodivos\u0165, \u010d\u00edm sa zni\u017euj\u00fa tepeln\u00e9 straty medzi zrnami\/dutinami, \u010d\u00edm sa \u010falej zvy\u0161uje tepeln\u00e1 vodivos\u0165; okrem toho \u010dist\u00e9 hranice z\u0155n tie\u017e pom\u00e1haj\u00fa zvy\u0161ova\u0165 tepeln\u00fa vodivos\u0165 zni\u017eovan\u00edm tepeln\u00fdch str\u00e1t medzi zrnami\/dutinami, \u010do v kone\u010dnom d\u00f4sledku vedie k v\u00e4\u010d\u0161ej tepelnej vodivosti medzi zrnami\/dutinami, \u010d\u00edm sa zvy\u0161uje tepeln\u00e1 vodivos\u0165 keramiky.<\/p>\n
SiC je zn\u00e1my svojou odolnos\u0165ou vo\u010di kor\u00f3zii v r\u00f4znych chemick\u00fdch prostrediach. Je to sp\u00f4soben\u00e9 najm\u00e4 t\u00fdm, \u017ee sa na jeho povrchu vytv\u00e1ra vrstva oxidu, ktor\u00e1 ho chr\u00e1ni pred priamym kontaktom s ak\u00fdmiko\u013evek potenci\u00e1lne koroz\u00edvnymi chemik\u00e1liami, pri\u010dom ide o inertn\u00fd materi\u00e1l s ve\u013emi n\u00edzkou chemickou reaktivitou, \u010do e\u0161te zvy\u0161uje jeho odolnos\u0165.<\/p>\n
Beztlakov\u00e1 spekan\u00e1 keramika z karbidu krem\u00edka sa m\u00f4\u017ee pochv\u00e1li\u0165 najvy\u0161\u0161ou odolnos\u0165ou proti kor\u00f3zii spomedzi neoxidovej keramiky, odol\u00e1va v\u0161etk\u00fdm be\u017en\u00fdm kyselin\u00e1m (chlorovod\u00edkovej, s\u00edrovej, hydrobr\u00f3movej a fluorovod\u00edkovej), v\u0161etk\u00fdm z\u00e1sad\u00e1m (aminy, pota\u0161 a kaustick\u00e1 s\u00f3da), ako aj oxida\u010dn\u00fdm m\u00e9di\u00e1m, ako je kyselina dusi\u010dn\u00e1. Jeho odolnos\u0165 proti opotrebovaniu v\u0161ak nedosahuje odolnos\u0165 kobalt-chr\u00f3mov\u00fdch cementovan\u00fdch karbidov volfr\u00e1mu, zatia\u013e \u010do diamant poskytuje v\u00e4\u010d\u0161iu ochranu proti opotrebovaniu.<\/p>\n
Reak\u010dne viazan\u00fd karbid krem\u00edka s\u00edce nem\u00e1 tak\u00fa odolnos\u0165 proti kor\u00f3zii a oderu, ale v\u010faka svojej vysokej tvrdosti, pevnosti pri zv\u00fd\u0161en\u00fdch teplot\u00e1ch a tepelnej vodivosti je vhodn\u00fd na v\u00fdrobu tesniacich pl\u00f4ch, \u010dast\u00ed \u010derpadiel a in\u00fdch vysoko v\u00fdkonn\u00fdch aplik\u00e1ci\u00ed. Okrem toho sa m\u00f4\u017ee pochv\u00e1li\u0165 jedn\u00fdm z najni\u017e\u0161\u00edch koeficientov tepelnej roz\u0165a\u017enosti medzi neoxidovou keramikou, \u010do zaru\u010duje optim\u00e1lny v\u00fdkon v r\u00f4znych priemyseln\u00fdch podmienkach.<\/p>\n
Spolo\u010dnos\u0165 Junty pon\u00faka \u0161irok\u00fd v\u00fdber tried spekan\u00e9ho karbidu krem\u00edka na zlep\u0161enie tribologick\u00fdch vlastnost\u00ed mechanick\u00fdch tesnen\u00ed, rezn\u00fdch n\u00e1strojov, opotrebovate\u013en\u00fdch kr\u00fa\u017ekov a ventilov\u00fdch sediel. Na\u0161i sk\u00fasen\u00ed pracovn\u00edci s vami bud\u00fa \u00fazko spolupracova\u0165 pri v\u00fdbere vhodnej triedy - bu\u010f reak\u010dne sp\u00e1jan\u00e9ho, alebo priamo spekan\u00e9ho karbidu krem\u00edka - pre va\u0161u aplik\u00e1ciu.<\/p>","protected":false},"excerpt":{"rendered":"
Silicon carbide exhibits very high strength at elevated temperatures, as well as great hardness, corrosion resistance, thermal shock resistance, and thermal shock tolerance. Reaction bonded silicon carbide (RBSiC) is produced by infiltrating liquid silicon into porous carbon or graphite preforms with precise dimensions. This process yields high-density products with precise dimensions. Hardness Silicon carbide, or […]<\/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-240","post","type-post","status-publish","format-standard","hentry","category-knowledge"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/ceramicatijolart.com\/sk\/wp-json\/wp\/v2\/posts\/240","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ceramicatijolart.com\/sk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ceramicatijolart.com\/sk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ceramicatijolart.com\/sk\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ceramicatijolart.com\/sk\/wp-json\/wp\/v2\/comments?post=240"}],"version-history":[{"count":1,"href":"https:\/\/ceramicatijolart.com\/sk\/wp-json\/wp\/v2\/posts\/240\/revisions"}],"predecessor-version":[{"id":241,"href":"https:\/\/ceramicatijolart.com\/sk\/wp-json\/wp\/v2\/posts\/240\/revisions\/241"}],"wp:attachment":[{"href":"https:\/\/ceramicatijolart.com\/sk\/wp-json\/wp\/v2\/media?parent=240"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ceramicatijolart.com\/sk\/wp-json\/wp\/v2\/categories?post=240"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ceramicatijolart.com\/sk\/wp-json\/wp\/v2\/tags?post=240"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}