{"id":6,"date":"2023-02-10T07:55:54","date_gmt":"2023-02-09T23:55:54","guid":{"rendered":"https:\/\/vecobr.com\/?p=6"},"modified":"2023-08-30T11:37:34","modified_gmt":"2023-08-30T03:37:34","slug":"silicon-carbide-structure-and-chemical-properties","status":"publish","type":"post","link":"https:\/\/vecobr.com\/da\/siliciumcarbids-struktur-og-kemiske-egenskaber\/","title":{"rendered":"siliciumcarbids struktur og kemiske egenskaber"},"content":{"rendered":"<p><strong>\u00a0Siliciumcarbid-struktur<\/strong><\/p>\n<p>Siliciumcarbid er en typisk kovalent bundet stabil forbindelse. Teoretisk set er siliciumcarbid lavet af SiC-tetraedre, men forskellen er kun parallel eller antiparallel binding. Der findes 75 varianter af SiC, f.eks. \u03b1-SiC, \u03b2-SiC, 3C-SiC, 4H-SiC, 15R-SiC osv. Alle disse strukturer kan opdeles i kvadratisk krystalsystem, sekskantet krystalsystem og rombisk krystalsystem, hvoraf \u03b1-SiC og \u03b2-SiC er de mest almindelige. \u03b2-SiC kan omdannes til \u03b1-SiC ved 2100-2400 \u00b0C, og \u03b2-SiC kan fremstilles af en simpel blanding af silicium og kulstof ved en temperatur p\u00e5 ca. 1450 \u00b0C. SiC-mikrostrukturen kan analyseres og kvantificeres i flere former ved hj\u00e6lp af transmissionselektronmikroskopi og r\u00f8ntgendiffraktionsdetekteringsteknikker. For at kunne skelne mellem de forskellige strukturer er det n\u00f8dvendigt med en nomenklatur. Denne nomenklatur er uforenelig med faselovskonventionen og mineralogisk nomenklatur, men er popul\u00e6r, fordi den er praktisk<\/p>\n<p><strong>\u00a0Siliciumcarbid Kemiske egenskaber<\/strong><\/p>\n<p>Siliciumcarbid i sig selv er let at oxidere, men det oxiderer for at danne en siliciumdioxidfilm, og oxidationsprocessen hindres gradvist. I luft begynder oxidationen af siliciumcarbid ved 800 \u00b0C, men meget langsomt; n\u00e5r temperaturen stiger, accelererer oxidationshastigheden kraftigt. Oxidationshastigheden for siliciumcarbid er 1,6 gange hurtigere i ilt end i luft; oxidationshastigheden aftager med tiden. Hvis oxidationsm\u00e6ngden plottes over tid, f\u00e5r man en typisk parabolsk graf. Dette afspejler den hindrende effekt af det beskyttende lag af silica p\u00e5 oxidationshastigheden af siliciumcarbidkeramik. Hvis der er stoffer, der kan fjerne eller bryde siliciumdioxidfilmen ved oxidation, vil siliciumcarbid let blive yderligere oxideret. For eksempel: jern, mangan og andre metaller har flere forbindelser, siliciumcarbid kan oxideres af deres oxider og kan generere forbindelser med lavt smeltepunkt med siliciumdioxid, kan erodere siliciumcarbidkeramik. For eksempel kan FeO i 1 300 \u2103, MnO i 1 360 \u2103 erodere siliciumcarbid; og CaO, MgO i 1 000 \u2103 kan erodere siliciumcarbidkeramik.<\/p>","protected":false},"excerpt":{"rendered":"<p>\u00a0Silicon carbide structure Silicon carbide is a typical covalently bonded stable compound.Theoretically, silicon carbide is made of SiC tetrahedra, but [&hellip;]<\/p>","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":""}},"ngg_post_thumbnail":0,"footnotes":""},"categories":[29],"tags":[],"class_list":["post-6","post","type-post","status-publish","format-standard","hentry","category-product-related"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/vecobr.com\/da\/wp-json\/wp\/v2\/posts\/6","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vecobr.com\/da\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/vecobr.com\/da\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/vecobr.com\/da\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/vecobr.com\/da\/wp-json\/wp\/v2\/comments?post=6"}],"version-history":[{"count":3,"href":"https:\/\/vecobr.com\/da\/wp-json\/wp\/v2\/posts\/6\/revisions"}],"predecessor-version":[{"id":10,"href":"https:\/\/vecobr.com\/da\/wp-json\/wp\/v2\/posts\/6\/revisions\/10"}],"wp:attachment":[{"href":"https:\/\/vecobr.com\/da\/wp-json\/wp\/v2\/media?parent=6"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vecobr.com\/da\/wp-json\/wp\/v2\/categories?post=6"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vecobr.com\/da\/wp-json\/wp\/v2\/tags?post=6"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}