Strukt\u016brin\u0117 keramika, dar vadinama in\u017einerine keramika, - tai pa\u017eangiosios keramikos klas\u0117, kuri daugiausia pasi\u017eymi mechaniniu, \u0161iluminiu, cheminiu ir kitu med\u017eiag\u0173 poveikiu. Strukt\u016brin\u0117 keramika pasi\u017eymi tokiomis savyb\u0117mis kaip atsparumas auk\u0161tai temperat\u016brai, atsparumas dilimui, atsparumas korozijai, atsparumas oksidacijai ir ma\u017eas \u0161liau\u017eimas auk\u0161toje temperat\u016broje. Jos gali atlaikyti at\u0161iauri\u0105 darbo aplink\u0105, kuriai metalin\u0117s med\u017eiagos ir polimerin\u0117s med\u017eiagos n\u0117ra kompetentingos. Jos pla\u010diai naudojamos aviacijoje, ma\u0161in\u0173, automobili\u0173, metalurgijos, chemijos pramon\u0117s, elektronikos ir kitose srityse ir tapo keramini\u0173 med\u017eiag\u0173 klase, kuri labai spar\u010diai vystosi. strukt\u016brinei keramikai daugiausia priskiriama oksid\u0173 keramika, nitrid\u0173 keramika ir karbid\u0173 keramika. Silicio karbido keramika daugiausia pristatoma toliau. Silicio karbidas, paprastai vadinamas karborundu, dar \u017einomas kaip karborundas, yra tipi\u0161kas kovalentini\u0173 ry\u0161i\u0173 junginys, kurio gamtoje beveik n\u0117ra. Kai 1890 m. Ewordas ir G. Achesonas nor\u0117jo susintetinti deimant\u0105, prid\u0117dami silicio \u012f angl\u012f kaip katalizatori\u0173, jie paruo\u0161\u0117 silicio karbid\u0105. \u0160iandien jis vis dar tiriamas ir tobulinamas.<\/p>\n
Silicio karbidas i\u0161 prad\u017ei\u0173 buvo naudojamas d\u0117l itin kiet\u0173 savybi\u0173, i\u0161 jo galima gaminti \u012fvairius \u0161lifavimo diskus, abrazyvinius audinius, abrazyvin\u012f popieri\u0173 ir \u012fvairias abrazyvines med\u017eiagas, kurios pla\u010diai naudojamos mechaninio apdirbimo pramon\u0117je. Per Antr\u0105j\u012f pasaulin\u012f kar\u0105 buvo nustatyta, kad silicio karbido keramika taip pat gali b\u016bti naudojama kaip reduktorius ir kaitinimo elementas plieno gamyboje, taip skatinant spar\u010di\u0105 jos pl\u0117tr\u0105. Atlikus tolesnius tyrimus nustatyta, kad jis pasi\u017eymi daugeliu puiki\u0173 savybi\u0173, toki\u0173 kaip auk\u0161tas temperat\u016brinis stabilumas, didelis \u0161iluminis laidumas, atsparumas r\u016bg\u0161\u010di\u0173 ir \u0161arm\u0173 korozijai, ma\u017eas pl\u0117timosi koeficientas ir geras atsparumas terminiams sm\u016bgiams.<\/p>\n
Silicio karbido kristalin\u0117s formos yra dvi: kubin\u0117 \u03b2- SIC4 ir heksagonin\u0117 \u03b1- SIC\u3002 Pagrindiniai silicio karbido gardel\u0117s strukt\u016briniai vienetai yra SIC4 ir CSI4 tetraedrai, persipinantys tarpusavyje. Tetraedrai turi t\u0105 pa\u010di\u0105 briaun\u0105 ir sudaro plok\u0161tumin\u012f sluoksn\u012f, o vir\u0161\u016bn\u0117s jungiasi su kitu tetraedr\u0173 sluoksniu, sudarydamos trimat\u012f mechanizm\u0105. Kadangi skirtingos tetraedr\u0173 sud\u0117jimo sekos gali sudaryti skirtingas strukt\u016bras, iki \u0161iol rasta \u0161imtai variant\u0173. Paprastai gardel\u0117s tipui \u017eym\u0117ti naudojami glausti ir intuityv\u016bs simboliai, t. y. raid\u0117s C, H, R, o skirtumui parodyti naudojamas vienetin\u0117je l\u0105stel\u0117je esan\u010di\u0173 sluoksni\u0173 skai\u010dius. Nors \u0161i\u0173 polimorf\u0173 gardel\u0117s konstantos skiriasi, juose esan\u010dios med\u017eiagos akivaizd\u017eiai nesikei\u010dia. silicio karbido keramika yra tipi\u0161kas valentinis junginys, ta\u010diau yra ir jonini\u0173 tip\u0173. Remiantis teoriniais skai\u010diavimais, 78% visos SI-C ry\u0161io energijos priklauso kovalentinei b\u016bsenai, o 22% - joninei b\u016bsenai. D\u0117l ma\u017eo S ir C atom\u0173 dyd\u017eio, ry\u0161io ilgio ir stipraus kovalenti\u0161kumo silicio karbido keramika pasi\u017eymi \u012fvairiomis savyb\u0117mis, pavyzd\u017eiui, dideliu kietumu, tam tikru mechaniniu atsparumu ir sunkiu sukepimu.<\/p>\n
Silicio karbidas yra tipi\u0161kas kovalentiniais ry\u0161iais suri\u0161tas stabilus junginys. Be to, jo difuzijos koeficientas yra ma\u017eas, tod\u0117l j\u012f sunku tankinti \u012fprastais sukepinimo metodais. Norint gauti tanki\u0105 silicio karbido keramik\u0105, b\u016btina prid\u0117ti tam tikr\u0173 sukepinimo pagalbini\u0173 med\u017eiag\u0173, kad padid\u0117t\u0173 pavir\u0161iaus energija arba pavir\u0161iaus plotas, ir taikyti specialius procesus. Pagal sukepinimo proces\u0105 silicio karbid\u0105 galima suskirstyti \u012f rekristalizuot\u0105 silicio karbido keramik\u0105, reakciniu b\u016bdu sukepint\u0105 silicio karbido keramik\u0105, be sl\u0117gio sukepint\u0105 silicio karbido keramik\u0105, kar\u0161tai presuot\u0105 sukepint\u0105 silicio karbido keramik\u0105, auk\u0161toje temperat\u016broje kar\u0161tai izostati\u0161kai presuot\u0105 sukepint\u0105 silicio karbido keramik\u0105 ir cheminio gar\u0173 nusodinimo silicio karbid\u0105. \u012evairiais procesais paruo\u0161to silicio karbido savyb\u0117s yra gana skirtingos, t. y. tuo pa\u010diu procesu paruo\u0161to SIC savyb\u0117s yra prastos d\u0117l skirting\u0173 \u017ealiav\u0173 ir pried\u0173.<\/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\/lt\/wp-json\/wp\/v2\/posts\/7","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/siliconcarbideceramic.net\/lt\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/siliconcarbideceramic.net\/lt\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/lt\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/lt\/wp-json\/wp\/v2\/comments?post=7"}],"version-history":[{"count":4,"href":"https:\/\/siliconcarbideceramic.net\/lt\/wp-json\/wp\/v2\/posts\/7\/revisions"}],"predecessor-version":[{"id":11,"href":"https:\/\/siliconcarbideceramic.net\/lt\/wp-json\/wp\/v2\/posts\/7\/revisions\/11"}],"wp:attachment":[{"href":"https:\/\/siliconcarbideceramic.net\/lt\/wp-json\/wp\/v2\/media?parent=7"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/lt\/wp-json\/wp\/v2\/categories?post=7"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/lt\/wp-json\/wp\/v2\/tags?post=7"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}