{"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\/fi\/piikarbidin-rakenne-ja-kemialliset-ominaisuudet\/","title":{"rendered":"piikarbidin rakenne ja kemialliset ominaisuudet"},"content":{"rendered":"<p><strong>\u00a0Piikarbidirakenne<\/strong><\/p>\n<p>Piikarbidi on tyypillinen kovalenttisesti sitoutunut vakaa yhdiste.Teoriassa piikarbidi koostuu SiC-tetraedereist\u00e4, mutta ero on vain yhdensuuntainen tai vastakkainen sidos. SiC:st\u00e4 on saatavilla 75 muunnosta, kuten \u03b1-SiC, \u03b2-SiC, 3C-SiC, 4H-SiC, 15R-SiC jne. Kaikki n\u00e4m\u00e4 rakenteet voidaan jakaa neli\u00f6m\u00e4iseen, kuusikulmaiseen ja rombiseen kidej\u00e4rjestelm\u00e4\u00e4n, joista \u03b1-SiC ja \u03b2-SiC ovat yleisimpi\u00e4. \u03b2-SiC voidaan muuntaa \u03b1-SiC:ksi 2100-2400 \u2103:n l\u00e4mp\u00f6tilassa, ja \u03b2-SiC voidaan valmistaa yksinkertaisesta piin ja hiilen seoksesta noin 1450 \u2103:n l\u00e4mp\u00f6tilassa. SiC:n mikrorakennetta voidaan analysoida ja kvantifioida useissa eri muodoissa k\u00e4ytt\u00e4en l\u00e4p\u00e4isyelektronimikroskopiaa ja r\u00f6ntgendiffraktiohavaintotekniikoita. Eri rakenteiden erottamiseksi toisistaan tarvitaan nimikkeist\u00f6\u00e4. T\u00e4m\u00e4 nimikkeist\u00f6 on ristiriidassa faasilakien ja mineralogisen nimikkeist\u00f6n kanssa, mutta se on suosittu, koska se on k\u00e4tev\u00e4.<\/p>\n<p><strong>\u00a0Piikarbidi Kemialliset ominaisuudet<\/strong><\/p>\n<p>Piikarbidi itsess\u00e4\u00e4n hapettuu helposti, mutta se hapettuu muodostaen piidioksidikalvon, ja hapettumisprosessi estyy v\u00e4hitellen. Ilmassa piikarbidin hapettuminen alkaa 800 \u2103:ssa, mutta hyvin hitaasti; l\u00e4mp\u00f6tilan noustessa hapettumisnopeus kiihtyy jyrk\u00e4sti. Piikarbidin hapettumisnopeus on 1,6 kertaa nopeampi hapessa kuin ilmassa; hapettumisnopeus hidastuu ajan my\u00f6t\u00e4. Jos hapettumisen m\u00e4\u00e4r\u00e4 piirret\u00e4\u00e4n ajan funktiona, saadaan tyypillinen parabolinen kuvaaja. T\u00e4m\u00e4 kuvastaa piidioksidin suojakerroksen est\u00e4v\u00e4\u00e4 vaikutusta piikarbidikeramiikan hapettumisnopeuteen. Hapettuessaan, jos on aineita, jotka voivat poistaa tai rikkoa piidioksidikalvon, piikarbidi hapettuu helposti edelleen. Esimerkiksi: raudalla, mangaanilla ja muilla metalleilla on useita yhdisteit\u00e4, piikarbidia voidaan hapettaa niiden oksideilla , ja ne voivat tuottaa alhaisen sulamispisteen yhdisteit\u00e4 piidioksidin kanssa, voivat heikent\u00e4\u00e4 piikarbidikeramiikkaa. Esimerkiksi FeO 1 300 \u2103:ssa, MnO 1 360 \u2103:ssa voi heikent\u00e4\u00e4 piikarbidia; ja CaO, MgO 1 000 \u2103:ssa voi heikent\u00e4\u00e4 piikarbidikeramiikkaa.<\/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\/fi\/wp-json\/wp\/v2\/posts\/6","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vecobr.com\/fi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/vecobr.com\/fi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/vecobr.com\/fi\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/vecobr.com\/fi\/wp-json\/wp\/v2\/comments?post=6"}],"version-history":[{"count":3,"href":"https:\/\/vecobr.com\/fi\/wp-json\/wp\/v2\/posts\/6\/revisions"}],"predecessor-version":[{"id":10,"href":"https:\/\/vecobr.com\/fi\/wp-json\/wp\/v2\/posts\/6\/revisions\/10"}],"wp:attachment":[{"href":"https:\/\/vecobr.com\/fi\/wp-json\/wp\/v2\/media?parent=6"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vecobr.com\/fi\/wp-json\/wp\/v2\/categories?post=6"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vecobr.com\/fi\/wp-json\/wp\/v2\/tags?post=6"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}