\u0160truktur\u00e1lna keramika, zn\u00e1ma aj ako technick\u00e1 keramika, je trieda modernej keramiky, ktor\u00e1 m\u00e1 najm\u00e4 mechanick\u00e9, tepeln\u00e9, chemick\u00e9 a in\u00e9 \u00fa\u010dinky materi\u00e1lov. \u0160truktur\u00e1lna keramika m\u00e1 vlastnosti odolnosti vo\u010di vysok\u00fdm teplot\u00e1m, odolnosti vo\u010di opotrebovaniu, odolnosti vo\u010di kor\u00f3zii, odolnosti vo\u010di oxid\u00e1cii a n\u00edzkej te\u010dnosti pri vysokej teplote. Dok\u00e1\u017eu odol\u00e1va\u0165 n\u00e1ro\u010dn\u00fdm pracovn\u00fdm podmienkam, na ktor\u00e9 nie s\u00fa sp\u00f4sobil\u00e9 kovov\u00e9 materi\u00e1ly a polym\u00e9rne materi\u00e1ly. \u0160iroko sa pou\u017e\u00edvaj\u00fa v letectve, stroj\u00e1rstve, automobilovom priemysle, metalurgii, chemickom priemysle, elektronike a in\u00fdch oblastiach a stali sa triedou keramick\u00fdch materi\u00e1lov, ktor\u00e9 sa ve\u013emi r\u00fdchlo rozv\u00edjaj\u00fa. medzi \u0161truktur\u00e1lnu keramiku patr\u00ed najm\u00e4 oxidov\u00e1 keramika, nitridov\u00e1 keramika a karbidov\u00e1 keramika. Karbidov\u00e1 keramika je predstaven\u00e1 najm\u00e4 ni\u017e\u0161ie. Karbid krem\u00edka, v\u0161eobecne zn\u00e1my ako karborundum, zn\u00e1my aj ako karborundum, je typick\u00e1 zl\u00fa\u010denina s kovalentnou v\u00e4zbou, ktor\u00e1 v pr\u00edrode takmer neexistuje. Ke\u010f v roku 1890 chceli Eword a G. Acheson syntetizova\u0165 diamant pridan\u00edm krem\u00edka do uhl\u00edka ako katalyz\u00e1tora, pripravili karbid krem\u00edka. V s\u00fa\u010dasnosti sa st\u00e1le sk\u00fama a vyv\u00edja.<\/p>\n
Karbid krem\u00edka sa p\u00f4vodne pou\u017e\u00edval kv\u00f4li svojej super tvrdosti, z ktorej sa daj\u00fa pripravi\u0165 r\u00f4zne br\u00fasne kot\u00fa\u010de, br\u00fasne tkaniny, br\u00fasny papier a r\u00f4zne br\u00fasiv\u00e1, a je \u0161iroko pou\u017e\u00edvan\u00fd v stroj\u00e1rskom priemysle. Po\u010das druhej svetovej vojny sa zistilo, \u017ee karbid krem\u00edka sa m\u00f4\u017ee pou\u017e\u00edva\u0165 aj ako reduk\u010dn\u00e9 \u010dinidlo a vykurovacie teleso pri v\u00fdrobe ocele, \u010do podporilo jeho r\u00fdchly rozvoj. \u010eal\u0161\u00edm v\u00fdskumom sa zistilo, \u017ee m\u00e1 mnoho vynikaj\u00facich vlastnost\u00ed, ako je vysok\u00e1 teplotn\u00e1 stabilita, vysok\u00e1 tepeln\u00e1 vodivos\u0165, odolnos\u0165 vo\u010di kor\u00f3zii kyselinami a z\u00e1sadami, n\u00edzky koeficient roz\u0165a\u017enosti a dobr\u00e1 odolnos\u0165 vo\u010di tepeln\u00fdm \u0161okom.<\/p>\n
Existuj\u00fa najm\u00e4 dve kry\u0161t\u00e1lov\u00e9 formy karbidu krem\u00edka, a to: kubick\u00e1 \u03b2- SIC4 a hexagon\u00e1lna \u03b1- SIC\u3002 Z\u00e1kladn\u00fdmi \u0161trukt\u00farnymi jednotkami mrie\u017eky karbidu krem\u00edka s\u00fa navz\u00e1jom sa prel\u00ednaj\u00face tetra\u00e9dre SIC4 a CSI4. Tetra\u00e9dre maj\u00fa spolo\u010dn\u00fa hranu a tvoria rovinn\u00fa vrstvu a vrcholy s\u00fa spojen\u00e9 s \u010fal\u0161ou vrstvou tetra\u00e9drov a vytv\u00e1raj\u00fa trojrozmern\u00fd mechanizmus. Ke\u010f\u017ee r\u00f4zne sekvencie ukladania tetra\u00e9drov m\u00f4\u017eu vytv\u00e1ra\u0165 r\u00f4zne \u0161trukt\u00fary, doteraz boli n\u00e1jden\u00e9 stovky variantov. Vo v\u0161eobecnosti sa na vyjadrenie typu mrie\u017eky pou\u017e\u00edvaj\u00fa stru\u010dn\u00e9 a intuit\u00edvne symboly, konkr\u00e9tne p\u00edsmen\u00e1 C, H, R, a na vyjadrenie rozdielu sa pou\u017e\u00edva po\u010det vrstiev obsiahnut\u00fdch v jednotkovej bunke. Hoci s\u00fa mrie\u017ekov\u00e9 kon\u0161tanty t\u00fdchto polymorfov odli\u0161n\u00e9, nie s\u00fa v nich zjavn\u00e9 \u017eiadne zmeny l\u00e1tok. keramick\u00fd karbid krem\u00edka je typickou valen\u010dnou zl\u00fa\u010deninou, ale existuj\u00fa aj niektor\u00e9 i\u00f3nov\u00e9 typy. Pod\u013ea teoretick\u00e9ho v\u00fdpo\u010dtu patr\u00ed 78% celkovej energie v\u00e4zby SI-C do kovalentn\u00e9ho stavu a 22% do i\u00f3nov\u00e9ho stavu. V\u010faka malej ve\u013ekosti at\u00f3mov S a C, d\u013a\u017eke v\u00e4zby a silnej kovalencii m\u00e1 keramika z karbidu krem\u00edka rad vlastnost\u00ed, ako je vysok\u00e1 tvrdos\u0165, ur\u010dit\u00e1 mechanick\u00e1 pevnos\u0165 a \u0165a\u017ek\u00e9 spekanie.<\/p>\n
Karbid krem\u00edka je typick\u00e1 stabiln\u00e1 zl\u00fa\u010denina viazan\u00e1 kovalentnou v\u00e4zbou. Okrem toho je jeho dif\u00fazny koeficient n\u00edzky, \u010do s\u0165a\u017euje jeho zhut\u0148ovanie be\u017en\u00fdmi met\u00f3dami spekania. Na z\u00edskanie hustej keramiky z karbidu krem\u00edka je potrebn\u00e9 prida\u0165 niektor\u00e9 spek\u00e1rske pomocn\u00e9 l\u00e1tky na zv\u00fd\u0161enie povrchovej energie alebo plochy povrchu a prija\u0165 \u0161peci\u00e1lne postupy. Pod\u013ea procesu spekania mo\u017eno karbid krem\u00edka rozdeli\u0165 na rekry\u0161talizovan\u00fa keramiku z karbidu krem\u00edka, reak\u010dne spekan\u00fa keramiku z karbidu krem\u00edka, beztlakovo spekan\u00fa keramiku z karbidu krem\u00edka, za tepla lisovan\u00fa spekan\u00fa keramiku z karbidu krem\u00edka, za tepla izostaticky lisovan\u00fa spekan\u00fa keramiku z karbidu krem\u00edka a keramiku z karbidu krem\u00edka s chemickou depoz\u00edciou p\u00e1r. Vlastnosti karbidu krem\u00edka pripraven\u00e9ho r\u00f4znymi procesmi s\u00fa dos\u0165 odli\u0161n\u00e9, to znamen\u00e1, \u017ee SIC pripraven\u00fd t\u00fdm ist\u00fdm procesom m\u00e1 zl\u00e9 vlastnosti v d\u00f4sledku r\u00f4znych surov\u00edn a pr\u00edsad.<\/p>","protected":false},"excerpt":{"rendered":"
Structural ceramics, also known as engineering ceramics, are a class of advanced ceramics that mainly exert the mechanical, thermal, chemical […]<\/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":[5],"tags":[],"class_list":["post-7","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\/7","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=7"}],"version-history":[{"count":4,"href":"https:\/\/siliconcarbideceramic.net\/sk\/wp-json\/wp\/v2\/posts\/7\/revisions"}],"predecessor-version":[{"id":11,"href":"https:\/\/siliconcarbideceramic.net\/sk\/wp-json\/wp\/v2\/posts\/7\/revisions\/11"}],"wp:attachment":[{"href":"https:\/\/siliconcarbideceramic.net\/sk\/wp-json\/wp\/v2\/media?parent=7"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/sk\/wp-json\/wp\/v2\/categories?post=7"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/sk\/wp-json\/wp\/v2\/tags?post=7"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}