Carbura de siliciu (SiC) este un compus sintetic extrem de dur din siliciu \u0219i carbon care se g\u0103se\u0219te \u00een mod natural sub form\u0103 de piatr\u0103 pre\u021bioas\u0103 moissanite \u0219i, \u00eentr-o mai mic\u0103 m\u0103sur\u0103, \u00een meteori\u021bii carbonacei chondrite.<\/p>\n
Produs prin topirea nisipului de siliciu \u0219i a cocsului la temperaturi ridicate \u00eentr-un cuptor electric, cuar\u021bul exist\u0103 \u00een cel pu\u021bin 70 de forme cristaline diferite; forma alfa cu structur\u0103 cristalin\u0103 hexagonal\u0103 similar\u0103 cu Wurtzitul fiind cea mai r\u0103sp\u00e2ndit\u0103.<\/p>\n
Carbura de siliciu, denumit\u0103 mai frecvent Carborundum, este un compus ceramic neoxid cu propriet\u0103\u021bi excep\u021bionale de duritate \u0219i rezisten\u021b\u0103 chimic\u0103, care se situeaz\u0103 pe locul doi dup\u0103 diamant. \u00cen plus, carbura de siliciu sub form\u0103 pur\u0103 rezist\u0103 oxid\u0103rii la temperaturi mai ridicate pentru o conductivitate \u0219i o conductivitate electric\u0103 mai fiabile.<\/p>\n
Se \u00eenc\u0103lze\u0219te nisipul silicios cu carbon \u00eentr-un cuptor electric pentru a produce SiC. Materialul cristalin de culoare verde p\u00e2n\u0103 la negru-alb\u0103strui poate fi apoi separat \u00een clase cu propriet\u0103\u021bi fizice diferite: de exemplu, clasa metalurgic\u0103 A are straturi grosiere, \u00een timp ce cristalele mai netede din clasa b formeaz\u0103 structuri mai netede.<\/p>\n
Aceste politipuri de structuri stratificate prezint\u0103 propriet\u0103\u021bi electrice, optice \u0219i termice deosebite. Leg\u0103turile lor atomice constau \u00een patru atomi de siliciu lega\u021bi de patru atomi de carbon \u00eentr-un model p\u0103trat neregulat care formeaz\u0103 patru cristale hexagonale; acest lucru ofer\u0103 propriet\u0103\u021bi semiconductoare cu band\u0103 larg\u0103. Prin extrudare sau presare izostatic\u0103 la rece, aceste materiale pot fi transformate \u00een tije sau tuburi pentru a fi utilizate ca tije \u0219i tuburi.<\/p>\n
Carbura de siliciu (SiC), denumit\u0103 mai frecvent carborundum, este un compus chimic dur din siliciu \u0219i carbon cu propriet\u0103\u021bi semiconductoare cu band\u0103 larg\u0103. Refractar \u00een natur\u0103, SiC este, de asemenea, cunoscut pentru conductivitatea termic\u0103 ridicat\u0103 \u0219i propriet\u0103\u021bile reduse de dilatare termic\u0103 care \u00eei confer\u0103 o rezisten\u021b\u0103 deosebit\u0103 la \u0219ocurile termice.<\/p>\n
SiC cristalin cristalizeaz\u0103 \u00eentr-o structur\u0103 compact\u0103 cu patru atomi de siliciu \u0219i patru atomi de carbon lega\u021bi \u00een coordonare tetraedric\u0103 \u0219i are peste 70 de politipuri; alfa SiC se g\u0103se\u0219te cel mai frecvent la temperaturi de peste 2000 de grade C cu structur\u0103 cristalin\u0103 hexagonal\u0103 similar\u0103 cu Wurtzite. \u00centre timp, modificarea beta cu structur\u0103 cristalin\u0103 zincblend\u0103 similar\u0103 diamantului \u0219i formarea de sferit\u0103 are loc la temperaturi mai sc\u0103zute.<\/p>\n
Carborundumul este o substan\u021b\u0103 extrem de rar\u0103 \u00een natur\u0103, dar un element de baz\u0103 \u00een meteori\u021bii din spa\u021biu boga\u021bi \u00een carbon. Sintetizat artificial pentru prima dat\u0103 \u00een 1891 de Edward Acheson ca parte a activit\u0103\u021bii sale de producere a diamantelor artificiale, materialul a fost descoperit \u00een mod natural \u00een meteoritul Canyon Diablo din Arizona \u00een 1893 \u0219i denumit moissanite dup\u0103 laureatul premiului Nobel Henri Moissan.<\/p>\n
Carbura de siliciu are o suprafa\u021b\u0103 extrem de dur\u0103, cu o valoare de 9 pe scara Mohs, ceea ce o face cea mai dur\u0103 ceramic\u0103 neoxidat\u0103 \u0219i unul dintre cele mai dure materiale \u00een general. Este un material excelent pentru aplica\u021bii care implic\u0103 uzur\u0103 mecanic\u0103, cum ar fi materialele abrazive \u0219i refractare, av\u00e2nd \u00een acela\u0219i timp propriet\u0103\u021bi termice bune care rezist\u0103 la medii cu temperaturi ridicate, precum \u0219i la \u0219ocuri termice.<\/p>\n
Siliciul \u00eenlocuie\u0219te jum\u0103tate din atomii de carbon, oferind propriet\u0103\u021bi \u00eembun\u0103t\u0103\u021bite de conduc\u021bie a c\u0103ldurii datorit\u0103 razei atomice similare \u00eentre siliciu \u0219i carbon - contribuind la reducerea \u00eempr\u0103\u0219tierii fononilor.<\/p>\n
Carbura de siliciu apare sub form\u0103 de cristale irizate de la galben la verde p\u00e2n\u0103 la negru alb\u0103strui, care se sublimeaz\u0103 prin descompunere la 2700degC. De\u0219i insolubil \u00een ap\u0103, SiC este solubil \u00een alcalii topite, cum ar fi NaOH \u0219i KOH, precum \u0219i \u00een fier topit, iar modulul Young \u0219i duritatea sa sunt determinate de textur\u0103, defectele de stivuire, dimensiunea gr\u0103un\u021bilor \u0219i natura grani\u021belor.<\/p>\n
Energia de band\u0103 larg\u0103 a carburii de siliciu \u00eei permite s\u0103 reziste la temperaturi \u0219i tensiuni mai ridicate dec\u00e2t siliciul, ceea ce o face potrivit\u0103 pentru aplica\u021bii care necesit\u0103 dispozitive electronice rapide, dar fiabile. \u00cen plus, capacitatea sa de a rezista la astfel de tensiuni este nepre\u021buit\u0103 \u00een sistemele de baterii pentru vehicule electrice care reduc at\u00e2t dimensiunea, c\u00e2t \u0219i greutatea prin eliminarea complet\u0103 a invertoarelor.<\/p>\n
SiC este un material popular datorit\u0103 combina\u021biei sale de propriet\u0103\u021bi ceramice \u0219i semiconductoare, care contribuie la progresul tehnologiei electronice. \u00cen plus, duritatea, rezisten\u021ba, dilatarea termic\u0103 redus\u0103 \u0219i rezisten\u021ba la reac\u021bii chimice au contribuit la cre\u0219terea popularit\u0103\u021bii sale.<\/p>\n
Carbura de siliciu este creat\u0103 prin \u00eenc\u0103lzirea nisipului de siliciu pur cu carbon \u00eentr-un cuptor electric, cre\u00e2nd lingouri at\u00e2t de calitate metalurgic\u0103, c\u00e2t \u0219i abraziv\u0103, cunoscute sub numele de a-SiC \u0219i b-SiC, \u00een func\u021bie de calitate \u0219i de utilizarea prev\u0103zut\u0103. Dup\u0103 formarea lingourilor, acestea sunt t\u0103iate \u00een diferite dimensiuni \u0219i forme, \u00een func\u021bie de aplica\u021biile dorite, \u00eenainte de a fi amestecate cu elemente suplimentare precum aluminiu sau azot pentru caracteristicile dorite.<\/p>","protected":false},"excerpt":{"rendered":"
Silicon Carbide (SiC) is an extremely hard synthetic compound of silicon and carbon that occurs naturally as the gem moissanite […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","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":[3],"tags":[],"class_list":["post-62","post","type-post","status-publish","format-standard","hentry","category-sic-knowledge"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/siliconcarbideceramic.net\/ro\/wp-json\/wp\/v2\/posts\/62","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/siliconcarbideceramic.net\/ro\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/siliconcarbideceramic.net\/ro\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/ro\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/ro\/wp-json\/wp\/v2\/comments?post=62"}],"version-history":[{"count":1,"href":"https:\/\/siliconcarbideceramic.net\/ro\/wp-json\/wp\/v2\/posts\/62\/revisions"}],"predecessor-version":[{"id":63,"href":"https:\/\/siliconcarbideceramic.net\/ro\/wp-json\/wp\/v2\/posts\/62\/revisions\/63"}],"wp:attachment":[{"href":"https:\/\/siliconcarbideceramic.net\/ro\/wp-json\/wp\/v2\/media?parent=62"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/ro\/wp-json\/wp\/v2\/categories?post=62"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/ro\/wp-json\/wp\/v2\/tags?post=62"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}