Strukturkeramik, \u00e4ven k\u00e4nd som teknisk keramik, \u00e4r en klass av avancerad keramik som huvudsakligen ut\u00f6var de mekaniska, termiska, kemiska och andra effekterna av material. Strukturkeramik har egenskaperna f\u00f6r h\u00f6g temperaturbest\u00e4ndighet, slitstyrka, korrosionsbest\u00e4ndighet, oxidationsbest\u00e4ndighet och l\u00e5g krypning under h\u00f6g temperatur. De kan motst\u00e5 den h\u00e5rda arbetsmilj\u00f6n som metallmaterial och polymermaterial inte \u00e4r kompetenta f\u00f6r. De anv\u00e4nds ofta inom flyg, maskiner, bil, metallurgi, kemisk industri, elektronik och andra omr\u00e5den och har blivit en klass av keramiska material som utvecklas mycket snabbt. Strukturkeramik inkluderar huvudsakligen oxidkeramik, nitridkeramik och karbidkeramik. Kiselkarbidkeramik introduceras huvudsakligen nedan. Kiselkarbid, allm\u00e4nt k\u00e4nd som karborundum, \u00e4ven k\u00e4nd som karborundum, \u00e4r en typisk kovalent bindningsf\u00f6rening som n\u00e4stan inte finns i naturen. \u00c5r 1890, n\u00e4r Eword och G. Acheson ville syntetisera diamant genom att tills\u00e4tta kisel i kol som katalysator, framst\u00e4llde de kiselkarbid. Idag studeras och utvecklas den fortfarande.<\/p>\n
Kiselkarbid anv\u00e4ndes ursprungligen p\u00e5 grund av dess superh\u00e5rda prestanda, som kan beredas till olika slipskivor, slipduk, slippapper och olika slipmedel, och anv\u00e4nds ofta i den mekaniska bearbetningsindustrin. Under andra v\u00e4rldskriget fann man att kiselkarbidkeramik ocks\u00e5 kunde anv\u00e4ndas som reduktionsmedel och v\u00e4rmeelement vid st\u00e5ltillverkning, vilket fr\u00e4mjade dess snabba utveckling. Med den fortsatta forskningen konstateras att den har m\u00e5nga utm\u00e4rkta egenskaper, s\u00e5som h\u00f6g temperaturstabilitet, h\u00f6g v\u00e4rmeledningsf\u00f6rm\u00e5ga, syra- och alkalikorrosionsbest\u00e4ndighet, l\u00e5g expansionskoefficient och god motst\u00e5ndskraft mot termisk chock.<\/p>\n
Det finns huvudsakligen tv\u00e5 kristallformer av kiselkarbid, n\u00e4mligen: kubisk \u03b2- SIC4 och hexagonal \u03b1- SIC\u3002 De grundl\u00e4ggande strukturella enheterna i kiselkarbidgitteret \u00e4r SIC4- och CSI4-tetraedrar som genomtr\u00e4nger varandra. Tetraederna delar samma kant f\u00f6r att bilda ett planlager, och h\u00f6rnen \u00e4r anslutna till n\u00e4sta lager av tetraeder f\u00f6r att bilda en tredimensionell mekanism. Eftersom olika tetraederstaplingssekvenser kan bilda olika strukturer har hundratals varianter hittats hittills. I allm\u00e4nhet anv\u00e4nds kortfattade och intuitiva symboler, n\u00e4mligen bokst\u00e4verna C, H, R, f\u00f6r att representera gittertypen, och antalet lager som ing\u00e5r i enhetscellen anv\u00e4nds f\u00f6r att visa skillnaden. \u00c4ven om gitterkonstanterna f\u00f6r dessa polymorfer \u00e4r olika, finns det ingen uppenbar f\u00f6r\u00e4ndring i \u00e4mnena i dem. kiselkarbidkeramik \u00e4r en typisk valensf\u00f6rening, men det finns ocks\u00e5 n\u00e5gra joniska typer. Enligt teoretisk ber\u00e4kning tillh\u00f6r 78% av den totala energin i SI-C-bindningen kovalent tillst\u00e5nd och 22% tillh\u00f6r joniskt tillst\u00e5nd. P\u00e5 grund av den lilla storleken p\u00e5 S- och C-atomer, bindningsl\u00e4ngden och den starka kovalensen har kiselkarbidkeramik en serie egenskaper, s\u00e5som h\u00f6g h\u00e5rdhet, viss mekanisk h\u00e5llfasthet och sv\u00e5r sintring.<\/p>\n
Kiselkarbid \u00e4r en typisk kovalent bindningsbunden stabil f\u00f6rening. Dessutom \u00e4r dess diffusionskoefficient l\u00e5g, vilket g\u00f6r det sv\u00e5rt att f\u00f6rt\u00e4ta med konventionella sintringsmetoder. Det \u00e4r n\u00f6dv\u00e4ndigt att l\u00e4gga till n\u00e5gra sintringshj\u00e4lpmedel f\u00f6r att \u00f6ka ytenergin eller ytan och anta speciella processer f\u00f6r att erh\u00e5lla t\u00e4t kiselkarbidkeramik. Enligt sintringsprocessen kan kiselkarbid delas in i omkristalliserad kiselkarbidkeramik, reaktionssintrad kiselkarbidkeramik, tryckl\u00f6s sintrad kiselkarbidkeramik, varmpressad sintrad kiselkarbidkeramik, h\u00f6gtemperatur varm isostatisk pressning sintrad kiselkarbidkeramik och kemisk \u00e5ngavs\u00e4ttning kiselkarbid. Egenskaperna hos kiselkarbid framst\u00e4lld genom olika processer \u00e4r helt olika, det vill s\u00e4ga SIC framst\u00e4lld genom samma process har d\u00e5lig prestanda p\u00e5 grund av olika r\u00e5varor och tillsatser.<\/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\/sv\/wp-json\/wp\/v2\/posts\/7","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/siliconcarbideceramic.net\/sv\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/siliconcarbideceramic.net\/sv\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/sv\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/sv\/wp-json\/wp\/v2\/comments?post=7"}],"version-history":[{"count":4,"href":"https:\/\/siliconcarbideceramic.net\/sv\/wp-json\/wp\/v2\/posts\/7\/revisions"}],"predecessor-version":[{"id":11,"href":"https:\/\/siliconcarbideceramic.net\/sv\/wp-json\/wp\/v2\/posts\/7\/revisions\/11"}],"wp:attachment":[{"href":"https:\/\/siliconcarbideceramic.net\/sv\/wp-json\/wp\/v2\/media?parent=7"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/sv\/wp-json\/wp\/v2\/categories?post=7"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/sv\/wp-json\/wp\/v2\/tags?post=7"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}