Karbid k\u0159em\u00edku, \u010dast\u011bji ozna\u010dovan\u00fd jako karborundum, je tvrd\u00fd jako diamant a vysoce odoln\u00fd proti opot\u0159eben\u00ed. Krom\u011b toho je d\u00edky sv\u00fdm keramick\u00fdm vlastnostem vhodn\u00fd do prost\u0159ed\u00ed s vysokou teplotou a nap\u011bt\u00edm.<\/p>\n
V\u00fdsledkem v\u00fdroby metodou Lely je pr\u00e1\u0161ek, kter\u00fd lze brousit do drah\u00fdch kamen\u016f moissanitu pro pou\u017eit\u00ed jako drahokam\u016f, zat\u00edmco v\u00fdrobci jej pou\u017e\u00edvaj\u00ed tak\u00e9 pro v\u00fdrobu brusn\u00fdch p\u0159edm\u011bt\u016f a v\u00fdrobk\u016f vy\u017eaduj\u00edc\u00edch tvrdost.<\/p>\n
Karbid k\u0159em\u00edku (SiC), zn\u00e1m\u00fd tak\u00e9 jako karborundum \/krbnm\/, je extr\u00e9mn\u011b tvrd\u00e1 slou\u010denina k\u0159em\u00edku a uhl\u00edku, kter\u00e1 vznik\u00e1 p\u0159irozen\u011b jako miner\u00e1l moissanit a od konce 19. stolet\u00ed se masov\u011b vyr\u00e1b\u00ed jako brusivo. Spojen\u00edm SiC do tvrd\u00e9 keramiky nebo jeho dopov\u00e1n\u00edm dus\u00edkem, fosforem, beryliem nebo hlin\u00edkem lze vytvo\u0159it polovodi\u010de n- nebo p-typu.<\/p>\n
Pr\u016fmyslov\u00fd SiC se obvykle vyr\u00e1b\u00ed Achesonov\u00fdm procesem zah\u0159\u00edv\u00e1n\u00edm k\u0159emi\u010dit\u00e9ho p\u00edsku se zdroji uhl\u00edku, jako je ropn\u00fd koks, na vysokou teplotu v otev\u0159en\u00e9 peci, \u010d\u00edm\u017e vznikaj\u00ed zrna zelen\u00e9 nebo \u010dern\u00e9 barvy v z\u00e1vislosti na stupni \u010distoty.<\/p>\n
SiC je zn\u00e1m\u00fd svou vynikaj\u00edc\u00ed tepelnou vodivost\u00ed a odolnost\u00ed proti korozi. D\u00edky n\u00edzk\u00e9mu koeficientu tepeln\u00e9 rozta\u017enosti, vysok\u00e9mu pom\u011bru pevnosti a tvrdosti, chemick\u00e9 stabilit\u011b a snadn\u00e9 obrobitelnosti slou\u017e\u00ed jako prvot\u0159\u00eddn\u00ed surovina v mnoha pr\u016fmyslov\u00fdch aplikac\u00edch, jako jsou vysoce kvalitn\u00ed \u017e\u00e1ruvzdorn\u00e9 materi\u00e1ly\/abraziva\/keramika [16].<\/p>\n
Karbid k\u0159em\u00edku (SiC) je technick\u00fd keramick\u00fd materi\u00e1l s jedine\u010dn\u00fdmi vlastnostmi, mezi n\u011b\u017e pat\u0159\u00ed chemick\u00e1 inertnost p\u0159i v\u0161ech teplot\u00e1ch, odolnost v\u016f\u010di tepeln\u00fdm \u0161ok\u016fm a vysok\u00e1 slinutelnost. SiC se pou\u017e\u00edv\u00e1 v r\u016fzn\u00fdch aplikac\u00edch technick\u00e9 keramiky, v\u010detn\u011b v\u00fdroby n\u00e1bytku pec\u00ed a za\u0159\u00edzen\u00ed pro manipulaci s kapalinami, jako\u017e i lo\u017eisek a d\u00edl\u016f podl\u00e9haj\u00edc\u00edch opot\u0159eben\u00ed. Mezi dal\u0161\u00ed vyu\u017eit\u00ed SiC pat\u0159\u00ed filtry pevn\u00fdch \u010d\u00e1stic a balistick\u00e1 ochrana. Spole\u010dnost Washington Mills nab\u00edz\u00ed drtic\u00ed, mlec\u00ed a t\u0159\u00eddic\u00ed za\u0159\u00edzen\u00ed schopn\u00e9 vyr\u00e1b\u011bt suroviny, kter\u00e9 spl\u0148uj\u00ed normy ANSI, FEPA a JIS.<\/p>\n
Velikost zrn SiC pr\u00e1\u0161k\u016f se m\u016f\u017ee li\u0161it v z\u00e1vislosti na jejich v\u00fdchoz\u00edm stavu a zdroji uhl\u00edku. Obl\u00edben\u00fdm postupem p\u0159\u00edpravy synt\u00e9zy SiC je termick\u00e1 redukce uhl\u00edkem; ta spo\u010d\u00edv\u00e1 v reakci sm\u011bsi obsahuj\u00edc\u00ed jeden mol SiO2 men\u0161\u00ed ne\u017e 200 mech s 1,5-3 moly zdroje uhl\u00edku; lou\u017een\u00ed kyselinou, zah\u0159\u00edv\u00e1n\u00ed a reakce vznikl\u00e9ho roztoku vylou\u010d\u00ed vznik skeln\u00e9ho uhl\u00edku.<\/p>\n
Pr\u00e1\u0161ky SiC vyroben\u00e9 pomoc\u00ed kvantitativn\u00ed anal\u00fdzy XRD jsou d\u00e1le analyzov\u00e1ny pomoc\u00ed tvaru \u010d\u00e1stic, granulometrick\u00e9ho slo\u017een\u00ed a anal\u00fdzy specifick\u00e9ho povrchu. Mezi d\u016fle\u017eit\u00e9 charakteristiky pat\u0159\u00ed tvar \u010d\u00e1stic, granulometrick\u00e9 slo\u017een\u00ed a specifick\u00fd povrch. \u010c\u00e1stice SiC obvykle vykazuj\u00ed ploch\u00e9, t\u0159\u00ed\u0161tiv\u00e9 struktury s defektn\u00edmi substrukturami charakterizovan\u00fdmi disloka\u010dn\u00edmi m\u0159\u00ed\u017ekami na jejich okraj\u00edch - co\u017e je ne\u017e\u00e1douc\u00ed vlastnost, kter\u00e1 by mohla m\u00edt negativn\u00ed dopad na procesy sp\u00e9k\u00e1n\u00ed.<\/p>\n
Karbid k\u0159em\u00edku m\u00e1 mnoho jedine\u010dn\u00fdch vlastnost\u00ed, kter\u00e9 mu umo\u017e\u0148uj\u00ed uplatn\u011bn\u00ed v r\u016fzn\u00fdch pr\u016fmyslov\u00fdch oblastech. Zejm\u00e9na je extr\u00e9mn\u011b tvrd\u00fd, jeho tvrdost dosahuje hodnoty 9 podle Mohse, nav\u00edc je tento materi\u00e1l chemicky inertn\u00ed a nab\u00edz\u00ed velkou odolnost proti ot\u011bru, tepelnou odolnost a\u017e do vysok\u00fdch teplot a m\u00e1 dobrou pevnost v tahu a n\u00edzk\u00fd koeficient tepeln\u00e9 rozta\u017enosti - to v\u0161e dohromady umo\u017e\u0148uje karbid k\u0159em\u00edku pou\u017e\u00edvat v mnoha pr\u016fmyslov\u00fdch odv\u011btv\u00edch.<\/p>\n
V\u00fdrobn\u00ed procesy karbidu k\u0159em\u00edku maj\u00ed obrovsk\u00fd vliv na jeho vlastnosti a pou\u017eit\u00ed. Edward Goodrich Acheson vyvinul Acheson\u016fv proces, kter\u00fd spo\u010d\u00edv\u00e1 v zah\u0159\u00edv\u00e1n\u00ed sm\u011bsi k\u0159emenn\u00e9ho p\u00edsku, ropn\u00e9ho koksu a d\u0159evn\u00ed \u0161t\u011bpky na extr\u00e9mn\u011b vysokou teplotu za \u00fa\u010delem vyvol\u00e1n\u00ed chemick\u00fdch reakc\u00ed, p\u0159i nich\u017e vznikaj\u00ed krystaly karbidu k\u0159em\u00edku - tyto krystaly lze pot\u00e9 rozdrtit na pr\u00e1\u0161ek nebo odl\u00edt do ingot\u016f ur\u010den\u00fdch k prodeji.<\/p>\n
Tento brusn\u00fd pr\u00e1\u0161ek se b\u011b\u017en\u011b pou\u017e\u00edv\u00e1 v leteck\u00e9m a automobilov\u00e9m pr\u016fmyslu k honov\u00e1n\u00ed a lapov\u00e1n\u00ed d\u00edl\u016f, aby se dos\u00e1hlo p\u0159esn\u00fdch rozm\u011br\u016f a hladk\u00e9ho povrchu, a tak\u00e9 v keramice, p\u0159i v\u00fdrob\u011b skla a oceli a jin\u00fdch kov\u016f. Spole\u010dnost Alter Technology vytvo\u0159ila z tohoto materi\u00e1lu r\u00e1diov\u00fd obvod, kter\u00fd odol\u00e1v\u00e1 extr\u00e9mn\u00edm podm\u00ednk\u00e1m ve vesm\u00edru.<\/p>\n
Karbid k\u0159em\u00edku je vynikaj\u00edc\u00ed neoxidov\u00fd materi\u00e1l s r\u016fzn\u00fdmi mo\u017enostmi pou\u017eit\u00ed d\u00edky sv\u00e9 tvrdosti (Mohsova tvrdost > 9), chemick\u00e9 inertnosti, n\u00edzk\u00e9mu koeficientu tepeln\u00e9 rozta\u017enosti a odolnosti v\u016f\u010di teplu i n\u00e1razu. Karbid k\u0159em\u00edku nach\u00e1z\u00ed d\u00edky sv\u00fdm tepeln\u011b vodiv\u00fdm vlastnostem vyu\u017eit\u00ed jako ot\u011bruvzdorn\u00e9 sou\u010d\u00e1sti v abrazivech nebo ot\u011bruvzdorn\u00e9 sou\u010d\u00e1sti v \u017e\u00e1ruvzdorn\u00e9 keramice a tak\u00e9 v polovodi\u010dov\u00fdch a elektrotechnick\u00fdch aplikac\u00edch.<\/p>\n
P\u0159i v\u00fdrob\u011b SiC v\u00fdrobci nejprve p\u0159i vysok\u00fdch teplot\u00e1ch kombinuj\u00ed amorfn\u00ed oxid k\u0159emi\u010dit\u00fd s uhl\u00edkem, obvykle s uheln\u00fdm koksem, a pot\u00e9 jej jemn\u011b rozemelou a sm\u00edchaj\u00ed s mal\u00fdm mno\u017estv\u00edm bauxitu, \u010d\u00edm\u017e vznikne p\u0159edlisek. Pot\u00e9 doch\u00e1z\u00ed k dopov\u00e1n\u00ed bu\u010f dus\u00edkem (SiC typu n), nebo b\u00f3rem, hlin\u00edkem a heliem (SiC typu p), v z\u00e1vislosti na po\u017eadovan\u00e9m pou\u017eit\u00ed.<\/p>\n
V\u00fdrobci pak tuto p\u0159edformu pou\u017e\u00edvaj\u00ed k v\u00fdrob\u011b kubick\u00e9ho karbidu k\u0159em\u00edku bu\u010f spojov\u00e1n\u00edm reakc\u00ed, nebo chemick\u00fdm napa\u0159ov\u00e1n\u00edm. Nej\u010dast\u011bji se pou\u017e\u00edv\u00e1 spojov\u00e1n\u00ed reakc\u00ed, kter\u00e9 zahrnuje zah\u0159\u00e1t\u00ed na teplotu 1410 \u00b0C a dopov\u00e1n\u00ed dus\u00edkem nebo b\u00f3rem pro v\u00fdrobu SiC n-typu. Chemick\u00e9 napa\u0159ov\u00e1n\u00ed vy\u017eaduje podstatn\u011b v\u00edce energie a za\u0159\u00edzen\u00ed pro sv\u016fj proces; spojov\u00e1n\u00ed reakc\u00ed vy\u017eaduje mnohem m\u00e9n\u011b.<\/p>\n
Vodiv\u00fd polovodi\u010dov\u00fd pr\u00e1\u0161ek SiC je navr\u017een tak, aby spl\u0148oval jedine\u010dn\u00e9 r\u016fstov\u00e9 pot\u0159eby r\u016fzn\u00fdch metod p\u011bstov\u00e1n\u00ed vodiv\u00fdch monokrystal\u016f karbidu k\u0159em\u00edku t\u0159et\u00ed generace typu n. Tento typ pr\u00e1\u0161ku m\u00e1 optim\u00e1ln\u00ed distribuci velikosti \u010d\u00e1stic s mal\u00fdm po\u010dtem dutin a nab\u00edz\u00ed \u00farove\u0148 \u010distoty produktu p\u0159esahuj\u00edc\u00ed 6N.<\/p>","protected":false},"excerpt":{"rendered":"
Jak vyrobit pr\u00e1\u0161ek karbidu k\u0159em\u00edku Karbid k\u0159em\u00edku, \u010dast\u011bji ozna\u010dovan\u00fd jako karborundum, je tvrd\u00fd jako diamant a vysoce odoln\u00fd proti opot\u0159eben\u00ed. Krom\u011b toho je d\u00edky sv\u00fdm keramick\u00fdm vlastnostem vhodn\u00fd do prost\u0159ed\u00ed s vysokou teplotou a nap\u011bt\u00edm. V\u00fdsledkem v\u00fdroby metodou Lely je pr\u00e1\u0161ek, kter\u00fd lze brousit do moissanitov\u00fdch drahokam\u016f pro pou\u017eit\u00ed jako drahokamy, zat\u00edmco ... \u010c\u00edst d\u00e1l<\/a><\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":["post-19","post","type-post","status-publish","format-standard","hentry","category-knowledge"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/siliconcarbidepowders.com\/cs\/wp-json\/wp\/v2\/posts\/19","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/siliconcarbidepowders.com\/cs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/siliconcarbidepowders.com\/cs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/siliconcarbidepowders.com\/cs\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/siliconcarbidepowders.com\/cs\/wp-json\/wp\/v2\/comments?post=19"}],"version-history":[{"count":1,"href":"https:\/\/siliconcarbidepowders.com\/cs\/wp-json\/wp\/v2\/posts\/19\/revisions"}],"predecessor-version":[{"id":20,"href":"https:\/\/siliconcarbidepowders.com\/cs\/wp-json\/wp\/v2\/posts\/19\/revisions\/20"}],"wp:attachment":[{"href":"https:\/\/siliconcarbidepowders.com\/cs\/wp-json\/wp\/v2\/media?parent=19"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/siliconcarbidepowders.com\/cs\/wp-json\/wp\/v2\/categories?post=19"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/siliconcarbidepowders.com\/cs\/wp-json\/wp\/v2\/tags?post=19"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}