Konstruk\u010dn\u00ed keramika, zn\u00e1m\u00e1 tak\u00e9 jako in\u017een\u00fdrsk\u00e1 keramika, je t\u0159\u00edda pokro\u010dil\u00e9 keramiky, kter\u00e1 m\u00e1 p\u0159edev\u0161\u00edm mechanick\u00e9, tepeln\u00e9, chemick\u00e9 a dal\u0161\u00ed \u00fa\u010dinky materi\u00e1l\u016f. Strukturn\u00ed keramika m\u00e1 vlastnosti jako odolnost proti vysok\u00fdm teplot\u00e1m, odolnost proti opot\u0159eben\u00ed, odolnost proti korozi, odolnost proti oxidaci a n\u00edzk\u00e9 te\u010den\u00ed za vysok\u00fdch teplot. Dok\u00e1\u017e\u00ed odol\u00e1vat n\u00e1ro\u010dn\u00e9mu pracovn\u00edmu prost\u0159ed\u00ed, pro kter\u00e9 nejsou kovov\u00e9 materi\u00e1ly a polymern\u00ed materi\u00e1ly zp\u016fsobil\u00e9. Jsou \u0161iroce pou\u017e\u00edv\u00e1ny v letectv\u00ed, stroj\u00edrenstv\u00ed, automobilov\u00e9m pr\u016fmyslu, metalurgii, chemick\u00e9m pr\u016fmyslu, elektronice a dal\u0161\u00edch oborech a staly se t\u0159\u00eddou keramick\u00fdch materi\u00e1l\u016f, kter\u00e9 se velmi rychle rozv\u00edjej\u00ed. mezi strukturn\u00ed keramiku pat\u0159\u00ed p\u0159edev\u0161\u00edm oxidov\u00e1 keramika, nitridov\u00e1 keramika a karbidov\u00e1 keramika. N\u00ed\u017ee je p\u0159edstavena p\u0159edev\u0161\u00edm karbidk\u0159emi\u010dit\u00e1 keramika. Karbid k\u0159em\u00edku, b\u011b\u017en\u011b zn\u00e1m\u00fd jako karborundum, zn\u00e1m\u00fd tak\u00e9 jako karborundum, je typick\u00e1 slou\u010denina s kovalentn\u00ed vazbou, kter\u00e1 se v p\u0159\u00edrod\u011b t\u00e9m\u011b\u0159 nevyskytuje. Kdy\u017e v roce 1890 cht\u011bli Eword a G. Acheson syntetizovat diamant p\u0159id\u00e1n\u00edm k\u0159em\u00edku do uhl\u00edku jako katalyz\u00e1toru, p\u0159ipravili karbid k\u0159em\u00edku. Dnes se st\u00e1le studuje a vyv\u00edj\u00ed.<\/p>\n
Karbid k\u0159em\u00edku byl p\u016fvodn\u011b pou\u017e\u00edv\u00e1n kv\u016fli sv\u00e9 mimo\u0159\u00e1dn\u00e9 tvrdosti, ze kter\u00e9 lze p\u0159ipravit r\u016fzn\u00e9 brusn\u00e9 kotou\u010de, brusn\u00e9 tkaniny, brusn\u00fd pap\u00edr a r\u016fzn\u00e1 brusiva, a je \u0161iroce pou\u017e\u00edv\u00e1n v pr\u016fmyslu strojn\u00edho zpracov\u00e1n\u00ed. Za druh\u00e9 sv\u011btov\u00e9 v\u00e1lky se zjistilo, \u017ee keramick\u00fd karbid k\u0159em\u00edku lze pou\u017e\u00edt tak\u00e9 jako reduk\u010dn\u00ed \u010dinidlo a topn\u00e9 t\u011bleso p\u0159i v\u00fdrob\u011b oceli, co\u017e podpo\u0159ilo jeho rychl\u00fd rozvoj. Dal\u0161\u00edm v\u00fdzkumem se zjistilo, \u017ee m\u00e1 mnoho vynikaj\u00edc\u00edch vlastnost\u00ed, jako je vysok\u00e1 teplotn\u00ed stabilita, vysok\u00e1 tepeln\u00e1 vodivost, odolnost proti korozi kyselinami a z\u00e1sadami, n\u00edzk\u00fd koeficient rozta\u017enosti a dobr\u00e1 odolnost proti tepeln\u00fdm \u0161ok\u016fm.<\/p>\n
Existuj\u00ed p\u0159edev\u0161\u00edm dv\u011b krystalov\u00e9 formy karbidu k\u0159em\u00edku, a to: kubick\u00e1 \u03b2- SIC4 a hexagon\u00e1ln\u00ed \u03b1- SIC\u3002 Z\u00e1kladn\u00edmi strukturn\u00edmi jednotkami m\u0159\u00ed\u017eky karbidu k\u0159em\u00edku jsou vz\u00e1jemn\u011b se prostupuj\u00edc\u00ed tetraedry SIC4 a CSI4. Tetraedry maj\u00ed spole\u010dnou hranu a tvo\u0159\u00ed rovinnou vrstvu, jej\u00ed\u017e vrcholy jsou spojeny s dal\u0161\u00ed vrstvou tetraedr\u016f a vytv\u00e1\u0159ej\u00ed trojrozm\u011brn\u00fd mechanismus. Proto\u017ee r\u016fzn\u00e9 sekvence skl\u00e1d\u00e1n\u00ed tetraedr\u016f mohou vytv\u00e1\u0159et r\u016fzn\u00e9 struktury, byly dosud nalezeny stovky variant. Obecn\u011b se pro zn\u00e1zorn\u011bn\u00ed typu m\u0159\u00ed\u017eky pou\u017e\u00edvaj\u00ed stru\u010dn\u00e9 a intuitivn\u00ed symboly, a to p\u00edsmena C, H, R, a pro zn\u00e1zorn\u011bn\u00ed rozd\u00edlu se pou\u017e\u00edv\u00e1 po\u010det vrstev obsa\u017een\u00fdch v jednotkov\u00e9 bu\u0148ce. A\u010dkoli se m\u0159\u00ed\u017ekov\u00e9 konstanty t\u011bchto polymorf\u016f li\u0161\u00ed, nen\u00ed v nich z\u0159ejm\u00e1 \u017e\u00e1dn\u00e1 zm\u011bna l\u00e1tek. keramick\u00fd karbid k\u0159em\u00edku je typickou valen\u010dn\u00ed slou\u010deninou, ale existuj\u00ed i n\u011bkter\u00e9 iontov\u00e9 typy. Podle teoretick\u00e9ho v\u00fdpo\u010dtu pat\u0159\u00ed 78% celkov\u00e9 energie vazby SI-C do kovalentn\u00edho stavu a 22% do iontov\u00e9ho stavu. D\u00edky mal\u00e9 velikosti atom\u016f S a C, d\u00e9lce vazby a siln\u00e9 kovalenci m\u00e1 keramika z karbidu k\u0159em\u00edku \u0159adu vlastnost\u00ed, jako je vysok\u00e1 tvrdost, ur\u010dit\u00e1 mechanick\u00e1 pevnost a obt\u00ed\u017en\u00e9 slinov\u00e1n\u00ed.<\/p>\n
Karbid k\u0159em\u00edku je typick\u00e1 stabiln\u00ed slou\u010denina v\u00e1zan\u00e1 kovalentn\u00ed vazbou. Krom\u011b toho m\u00e1 n\u00edzk\u00fd koeficient dif\u00faze, co\u017e zt\u011b\u017euje jeho zhutn\u011bn\u00ed b\u011b\u017en\u00fdmi metodami sp\u00e9k\u00e1n\u00ed. Pro z\u00edsk\u00e1n\u00ed hust\u00e9 keramiky z karbidu k\u0159em\u00edku je nutn\u00e9 p\u0159idat n\u011bkter\u00e9 pomocn\u00e9 sp\u00e9kac\u00ed l\u00e1tky pro zv\u00fd\u0161en\u00ed povrchov\u00e9 energie nebo plochy povrchu a pou\u017e\u00edt speci\u00e1ln\u00ed postupy. Podle zp\u016fsobu slinov\u00e1n\u00ed lze karbid k\u0159em\u00edku rozd\u011blit na rekrystalizovanou keramiku z karbidu k\u0159em\u00edku, reak\u010dn\u011b slinutou keramiku z karbidu k\u0159em\u00edku, beztlakov\u011b slinutou keramiku z karbidu k\u0159em\u00edku, za tepla lisovanou slinutou keramiku z karbidu k\u0159em\u00edku, vysokoteplotn\u00ed za tepla izostaticky lisovanou slinutou keramiku z karbidu k\u0159em\u00edku a chemickou depozici z par karbidu k\u0159em\u00edku. Vlastnosti karbidu k\u0159em\u00edku p\u0159ipraven\u00e9ho r\u016fzn\u00fdmi postupy jsou zna\u010dn\u011b odli\u0161n\u00e9, to znamen\u00e1, \u017ee SIC p\u0159ipraven\u00fd stejn\u00fdm postupem m\u00e1 \u0161patn\u00e9 vlastnosti v d\u016fsledku r\u016fzn\u00fdch surovin a p\u0159\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\/cs\/wp-json\/wp\/v2\/posts\/7","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/comments?post=7"}],"version-history":[{"count":4,"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/posts\/7\/revisions"}],"predecessor-version":[{"id":11,"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/posts\/7\/revisions\/11"}],"wp:attachment":[{"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/media?parent=7"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/categories?post=7"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/tags?post=7"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}