Carbura de siliciu (SiC), formula chimic\u0103 SiC, este un compus cristalin extrem de dur (9 pe scara Mohs), produs sintetic, compus din siliciu \u0219i carbon. De obicei, are un aspect negru-alb\u0103strui cu un efect de iriza\u021bie.<\/p>\n
Produs\u0103 industrial prin amestecarea siliciului cu carbonul \u00een condi\u021bii de cuptor electric la temperaturi ridicate, carbura de siliciu se g\u0103se\u0219te \u0219i \u00een stare natural\u0103 sub form\u0103 de moissanit \u00een cantit\u0103\u021bi foarte mici.<\/p>\n
Carbura de siliciu (abreviat\u0103 SiC) este un compus cristalin de siliciu \u0219i carbon, produs sintetic \u0219i extrem de dur, cunoscut pentru durabilitatea \u0219i punctul s\u0103u de topire ridicat. \u00cenc\u0103 de la sf\u00e2r\u0219itul secolului al XIX-lea, SiC a fost utilizat ca material abraziv pentru fabricarea \u0219mirghelului, a ro\u021bilor de \u0219lefuit \u0219i a uneltelor de t\u0103iere; mai recent, a devenit, de asemenea, utilizat pe scar\u0103 larg\u0103 pentru produc\u021bia de ceramic\u0103 dur\u0103, c\u0103ptu\u0219eli refractare dure pentru cuptoare industriale, c\u0103r\u0103mizi de \u00eenalt\u0103 temperatur\u0103 pentru medii cu temperaturi ridicate, piese rezistente la uzur\u0103 \u00een pompe \u0219i motoare de rachet\u0103, precum \u0219i substraturi semiconductoare utilizate pentru fabricarea diodelor cu emisie de lumin\u0103 (LED).<\/p>\n
\u00cen stare solid\u0103, are forma unui cristal irizat, de la galben la verde p\u00e2n\u0103 la negru alb\u0103strui, cu o temperatur\u0103 de sublimare de 2700 \u00b0C \u0219i insolubil \u00een majoritatea lichidelor, inclusiv \u00een ap\u0103 \u0219i \u00een majoritatea acizilor\/alcalinelor\/s\u0103rurilor topite. \u00cen plus, rezisten\u021ba sa la \u0219ocurile termice este foarte sc\u0103zut\u0103, \u00een timp ce ratele de dilatare termic\u0103 r\u0103m\u00e2n minime.<\/p>\n
Carbura de siliciu este un material ideal pentru fabricarea pl\u0103cilor refractare ale schimb\u0103toarelor de c\u0103ldur\u0103 utilizate pentru procesarea solu\u021biilor chimice fierbin\u021bi, cum ar fi acidul sulfuric foarte concentrat sau solu\u021bia de hidroxid de sodiu, datorit\u0103 conductivit\u0103\u021bii sale termice excelente \u0219i capacit\u0103\u021bii de a rezista la temperaturi extreme \u00een timpul acestor procese. \u00cen plus, carbura de siliciu asigur\u0103 un transfer rapid de c\u0103ldur\u0103 datorit\u0103 conduc\u021biei rapide a c\u0103ldurii.<\/p>\n
Carbura de siliciu (SiC) este un material cristalin artificial, sintetic, cu numeroase utiliz\u0103ri. Are un punct de topire ridicat, densitate \u0219i structur\u0103 cristalin\u0103 tetraedric\u0103 cu nuan\u021be care variaz\u0103 de la galben-verzui la cristale irizate negru-alb\u0103strui.<\/p>\n
Dur \u0219i rezistent la substan\u021be chimice la temperaturi \u0219i medii extreme, diamantul este un material abraziv popular utilizat pentru opera\u021biunile industriale de rectificare \u0219i prelucrare, precum \u0219i utilizat pe scar\u0103 larg\u0103 \u00een c\u0103ptu\u0219elile refractare \u0219i \u00een produc\u021bia de ceramic\u0103 \u0219i semiconductoare electronice.<\/p>\n
Pietrele pre\u021bioase moissanite pot fi g\u0103site \u00een mod natural \u00een unii meteori\u021bi \u0219i depozite de corindon, \u00een timp ce majoritatea SiC este produs industrial. Alpha SiC este cel mai des \u00eent\u00e2lnit ca cel mai r\u0103sp\u00e2ndit polimorf al s\u0103u, cu structur\u0103 cristalin\u0103 hexagonal\u0103 (similar\u0103 cu Wurtzite). Modificarea beta cu structur\u0103 cristalin\u0103 de blende de zinc a fost rareori utilizat\u0103 comercial p\u00e2n\u0103 recent, c\u00e2nd structura sa de blende de zinc a f\u0103cut-o potrivit\u0103 ca material de suport pentru catalizatori eterogeni datorit\u0103 suprafe\u021bei sale mai mari dec\u00e2t forma alfa.<\/p>\n
Carbura de siliciu (SiC) este un material ceramic refractar extrem de dur, cu rezisten\u021b\u0103 excep\u021bional\u0103 \u0219i rezisten\u021b\u0103 la coroziune, capabil s\u0103 suporte temperaturi foarte ridicate f\u0103r\u0103 s\u0103 se degradeze. \u00cen plus, SiC prezint\u0103 o conductivitate termic\u0103 excelent\u0103 \u0219i o dilatare termic\u0103 limitat\u0103 \u0219i r\u0103m\u00e2ne rezistent la majoritatea acizilor sau alcalinilor, precum \u0219i la s\u0103rurile topite.<\/p>\n
SiC este un semiconductor cu band\u0103 larg\u0103; aceasta \u00eenseamn\u0103 c\u0103 necesit\u0103 mai mult\u0103 energie dec\u00e2t siliciul pentru a transfera electronii \u00een banda sa de conduc\u021bie, ceea ce permite frecven\u021be de comutare mai mari \u0219i o conversie mai eficient\u0103 a energiei. SiC poate fi dopat cu azot sau fosfor pentru caracteristici de tip n \u0219i cu bor, galiu sau aluminiu pentru caracteristici de tip p.<\/p>\n
Metodele de produc\u021bie variaz\u0103, de la pulberi cu granula\u021bie grosier\u0103 \u0219i fin\u0103, past\u0103 sau gel dur, turnare prin extrudare \u00een forme solide prin extrudare \u0219i presare izostatic\u0103 la rece, prin metoda Lely de cre\u0219tere a cristalelor unice pentru t\u0103ierea pietrelor pre\u021bioase cunoscute sub numele de pietre moissanite sintetice, dar majoritatea materialului produs este utilizat industrial.<\/p>\n
Carbura de siliciu poate rezista la temperaturi ridicate \u0219i la coroziune, r\u0103m\u00e2n\u00e2nd \u00een acela\u0219i timp inert\u0103 din punct de vedere chimic; acest lucru \u00eei permite s\u0103 reziste f\u0103r\u0103 efecte adverse la acizi, baze \u0219i s\u0103ruri.<\/p>\n
Descrierea materialului: Carbura de siliciu este un izolator, dar poate fi modificat\u0103 pentru a prezenta semiconductivitate prin dopare controlat\u0103, oferind propriet\u0103\u021bi de band\u0103 larg\u0103 ideale pentru aplica\u021bii semiconductoare.<\/p>\n
Produc\u021bia industrial\u0103 de carbur\u0103 de siliciu \u00eencepe prin \u00eenc\u0103lzirea nisipului de cuar\u021b de silice pur\u0103 (SiO2) \u0219i a cocsului de petrol m\u0103cinat la o temperatur\u0103 extrem de ridicat\u0103 folosind cuptoare cu rezisten\u021b\u0103 electric\u0103, ceea ce duce la ob\u021binerea a dou\u0103 tipuri de poli - alfa \u0219i beta. A-SiC este cel mai comun dintre cele dou\u0103, cu structuri cristaline hexagonale similare wurtzitei; \u00een timp ce b-SiC prezint\u0103 structuri cristaline de zinc blende similare diamantului.<\/p>\n
Ambele forme au numeroase utiliz\u0103ri; aceste substan\u021be pot fi g\u0103site \u00een procesele de \u0219lefuire, honuire \u0219i sablare, precum \u0219i \u00een uneltele de acoperire, cum ar fi burghiile pentru procesele de t\u0103iere. \u00cen plus, ambele forme se g\u0103sesc frecvent \u00een articole sportive moderne, cum ar fi skateboard-urile \u0219i banda adeziv\u0103, \u0219i sunt utilizate ca materiale refractare pentru cuptoare, precum \u0219i ca componente ceramice ale turbinelor cu gaz.<\/p>","protected":false},"excerpt":{"rendered":"
Silicon carbide (SiC), chemical formula SiC, is an extremely hard (9 on Mohs scale), synthetically produced crystalline compound composed of silicon and carbon. Usually appearing bluish-black with an iridescence effect. Industrially produced by mixing silica with carbon under high temperature electric furnace conditions, silica carbide also occurs naturally as moissanite mineral in very small quantities. […]<\/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":[64],"tags":[],"class_list":["post-194","post","type-post","status-publish","format-standard","hentry","category-knowledge"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/ceramicatijolart.com\/ro\/wp-json\/wp\/v2\/posts\/194","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ceramicatijolart.com\/ro\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ceramicatijolart.com\/ro\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ceramicatijolart.com\/ro\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ceramicatijolart.com\/ro\/wp-json\/wp\/v2\/comments?post=194"}],"version-history":[{"count":1,"href":"https:\/\/ceramicatijolart.com\/ro\/wp-json\/wp\/v2\/posts\/194\/revisions"}],"predecessor-version":[{"id":195,"href":"https:\/\/ceramicatijolart.com\/ro\/wp-json\/wp\/v2\/posts\/194\/revisions\/195"}],"wp:attachment":[{"href":"https:\/\/ceramicatijolart.com\/ro\/wp-json\/wp\/v2\/media?parent=194"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ceramicatijolart.com\/ro\/wp-json\/wp\/v2\/categories?post=194"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ceramicatijolart.com\/ro\/wp-json\/wp\/v2\/tags?post=194"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}