Beztlakov\u00e9 slinov\u00e1n\u00ed karbidu k\u0159em\u00edku je pova\u017eov\u00e1no za nejslibn\u011bj\u0161\u00ed slinov\u00e1n\u00ed karbidu k\u0159em\u00edku a beztlakov\u00fdm slinov\u00e1n\u00edm lze p\u0159ipravit slo\u017eit\u00e9 tvary a velk\u00e9 rozm\u011bry keramiky z karbidu k\u0159em\u00edku. V z\u00e1vislosti na mechanismu slinov\u00e1n\u00ed lze tento druh slinut\u00e9ho karbidu k\u0159em\u00edku d\u00e1le rozd\u011blit na slinov\u00e1n\u00ed v pevn\u00e9 f\u00e1zi a slinov\u00e1n\u00ed v kapaln\u00e9 f\u00e1zi. \u03b2-SiC obsahuj\u00edc\u00ed stopov\u00e9 mno\u017estv\u00ed SiO lze slinovat za atmosf\u00e9rick\u00e9ho tlaku p\u0159id\u00e1n\u00edm B a C. Tato metoda v\u00fdrazn\u011b zlep\u0161uje kinetiku slinov\u00e1n\u00ed karbidu k\u0159em\u00edku. Po p\u0159id\u00e1n\u00ed vhodn\u00e9ho mno\u017estv\u00ed B se B b\u011bhem sp\u00e9k\u00e1n\u00ed nach\u00e1z\u00ed na hranic\u00edch zrn SiC a \u010d\u00e1ste\u010dn\u011b tvo\u0159\u00ed s SiC pevn\u00fd roztok, \u010d\u00edm\u017e se sni\u017euje energie na hranic\u00edch zrn SiC. Dopov\u00e1n\u00ed m\u00edrn\u00e9ho mno\u017estv\u00ed voln\u00e9ho C je pro sp\u00e9k\u00e1n\u00ed v pevn\u00e9 f\u00e1zi v\u00fdhodn\u00e9, proto\u017ee povrch SiC je obvykle oxidov\u00e1n mal\u00fdm mno\u017estv\u00edm generovan\u00e9ho SiO a p\u0159\u00eddavek m\u00edrn\u00e9ho mno\u017estv\u00ed C napom\u00e1h\u00e1 tomu, \u017ee se film SiO na povrchu SiC redukuje a odstra\u0148uje, \u010d\u00edm\u017e se zvy\u0161uje povrchov\u00e1 energie. Sp\u00e9k\u00e1n\u00ed v kapaln\u00e9 f\u00e1zi v\u0161ak bude m\u00edt negativn\u00ed \u00fa\u010dinek, proto\u017ee C bude reagovat s oxidov\u00fdmi p\u0159\u00edsadami za vzniku plynu, vzniku velk\u00e9ho mno\u017estv\u00ed otvor\u016f v keramick\u00e9m sp\u00e9kac\u00edm t\u011blese, co\u017e ovlivn\u00ed proces zhu\u0161\u0165ov\u00e1n\u00ed. \u010cistota, jemnost a f\u00e1zov\u00e9 slo\u017een\u00ed suroviny jsou v procesu slinov\u00e1n\u00ed karbidu k\u0159em\u00edku velmi d\u016fle\u017eit\u00e9. s. Proehazka slinoval slinut\u00fd karbid k\u0159em\u00edku s hustotou vy\u0161\u0161\u00ed ne\u017e 98% p\u0159i 2020 \u00b0C za atmosf\u00e9rick\u00e9ho tlaku sou\u010dasn\u00fdm p\u0159id\u00e1n\u00edm vhodn\u00e9ho mno\u017estv\u00ed B a C k ultrajemn\u00fdm pr\u00e1\u0161k\u016fm \u03b2-SiC (obsahuj\u00edc\u00edm m\u00e9n\u011b ne\u017e 2% kysl\u00edku). Syst\u00e9m SiC-B-C v\u0161ak pat\u0159\u00ed do kategorie slinov\u00e1n\u00ed v pevn\u00e9 f\u00e1zi, kter\u00e9 vy\u017eaduje vysokou teplotu slinov\u00e1n\u00ed a n\u00edzkou lomovou hou\u017eevnatost, lomov\u00fd zp\u016fsob je typick\u00fd pr\u016fchoz\u00ed lom, hrub\u00e1 zrna a \u0161patn\u00e1 rovnom\u011brnost. Zahrani\u010dn\u00ed v\u00fdzkum SiC se soust\u0159e\u010fuje p\u0159edev\u0161\u00edm na sp\u00e9k\u00e1n\u00ed v kapaln\u00e9 f\u00e1zi, tj. ur\u010dit\u00fd po\u010det sp\u00e9kac\u00edch p\u0159\u00edsad, p\u0159i ni\u017e\u0161\u00ed teplot\u011b, aby se dos\u00e1hlo zhutn\u011bn\u00ed SiC. Sp\u00e9k\u00e1n\u00ed SiC v kapaln\u00e9 f\u00e1zi nejen sni\u017euje teplotu sp\u00e9k\u00e1n\u00ed oproti sp\u00e9k\u00e1n\u00ed v pevn\u00e9 f\u00e1zi, ale tak\u00e9 zlep\u0161uje mikrostrukturu, a t\u00edm se zlep\u0161uj\u00ed vlastnosti sp\u00e9kan\u00e9ho t\u011blesa ve srovn\u00e1n\u00ed s vlastnostmi t\u011blesa sp\u00e9kan\u00e9ho v pevn\u00e9 f\u00e1zi.
\nM. Omori a kol. pou\u017eili oxidy vz\u00e1cn\u00fdch zemin ve sm\u011bsi s AlO nebo boridy k hust\u00e9mu slinov\u00e1n\u00ed SiC. Suzuki naproti tomu sp\u00e9kal SiC pouze s AlO jako p\u0159\u00edsadou p\u0159i teplot\u011b p\u0159ibli\u017en\u011b 2000 \u00b0C. A. Mulla a kol. sp\u00e9kali 0,5 \u03bcm \u03b2-SiC (s mal\u00fdm mno\u017estv\u00edm SiO na povrchu \u010d\u00e1stic) s AlO a YO jako p\u0159\u00edsadami p\u0159i ,1850-1950 \u00b0C a z\u00edskali relativn\u00ed hustotu keramiky SiC, kter\u00e1 byla v\u011bt\u0161\u00ed ne\u017e 95% teoretick\u00e9 hustoty, a zrna byla jemn\u00e1, s pr\u016fm\u011brnou velikost\u00ed 1,5 \u03bcm.
\nBylo zji\u0161t\u011bno, \u017ee mikrostruktura keramiky z karbidu k\u0159em\u00edku m\u00e1 hrub\u00e1 zrna a ty\u010dinkovitou strukturu s dobrou lomovou hou\u017eevnatost\u00ed. Ty\u010dinkovit\u00e1 zrna zvy\u0161uj\u00ed lomovou hou\u017eevnatost a z\u00e1rove\u0148 sni\u017euj\u00ed pevnost keramiky z karbidu k\u0159em\u00edku. Za \u00fa\u010delem dosa\u017een\u00ed lep\u0161\u00ed pevnosti a hou\u017eevnatosti p\u0159i sou\u010dasn\u00e9m sn\u00ed\u017een\u00ed teploty slinov\u00e1n\u00ed bylo u\u010din\u011bno mnoho pokus\u016f o zlep\u0161en\u00ed vlastnost\u00ed tohoto slinut\u00e9ho karbidu k\u0159em\u00edku \u00fapravou slo\u017een\u00ed skeln\u00e9 f\u00e1ze pomoc\u00ed r\u016fzn\u00fdch p\u0159\u00edsad. B\u011bhem procesu sp\u00e9k\u00e1n\u00ed vedlo zaveden\u00ed kapaln\u00e9 f\u00e1ze na hranici zrn a jedine\u010dn\u00e9 mezif\u00e1zov\u00e9 struktury k oslaben\u00ed mezif\u00e1zov\u00e9 struktury a lom materi\u00e1lu se zm\u011bnil na \u00fapln\u00fd pod\u00e9ln\u00fd lomov\u00fd re\u017eim, co\u017e vedlo k v\u00fdrazn\u00e9mu zv\u00fd\u0161en\u00ed pevnosti a hou\u017eevnatosti materi\u00e1lu. Av\u0161ak vzhledem k tomu, \u017ee p\u0159i pou\u017eit\u00ed p\u0159\u00edsady AlO vznik\u00e1 sklovit\u00e1 f\u00e1ze s n\u00edzk\u00fdm bodem t\u00e1n\u00ed a vysokou t\u011bkavost\u00ed, kter\u00e1 p\u0159i vy\u0161\u0161\u00edch teplot\u00e1ch podl\u00e9h\u00e1 siln\u00e9mu odpa\u0159ov\u00e1n\u00ed, co\u017e zp\u016fsobuje \u00fabytek hmotnosti materi\u00e1lu a nep\u0159\u00edzniv\u011b ovliv\u0148uje hutn\u011bn\u00ed materi\u00e1lu, je t\u0159eba hmotnostn\u00ed pod\u00edl AlO v p\u0159\u00edsad\u011b vhodn\u011b zv\u00fd\u0161it.<\/p>","protected":false},"excerpt":{"rendered":"
Beztlaku slinut\u00fd karbid k\u0159em\u00edku je pova\u017eov\u00e1n za nejslibn\u011bj\u0161\u00ed typ slinut\u00e9ho karbidu k\u0159em\u00edku a pomoc\u00ed procesu beztlaku slinov\u00e1n\u00ed lze vyr\u00e1b\u011bt keramick\u00e9 d\u00edly z karbidu k\u0159em\u00edku slo\u017eit\u00fdch tvar\u016f a velk\u00fdch rozm\u011br\u016f. V z\u00e1vislosti na mechanismu slinov\u00e1n\u00ed lze tento druh slinut\u00e9ho karbidu k\u0159em\u00edku d\u00e1le rozd\u011blit na slinov\u00e1n\u00ed v pevn\u00e9 f\u00e1zi a slinov\u00e1n\u00ed v kapaln\u00e9 f\u00e1zi. \u03b2-SiC obsahuj\u00edc\u00ed\u2026 <\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"neve_meta_sidebar":"","neve_meta_container":"","neve_meta_enable_content_width":"","neve_meta_content_width":0,"neve_meta_title_alignment":"","neve_meta_author_avatar":"","neve_post_elements_order":"","neve_meta_disable_header":"","neve_meta_disable_footer":"","neve_meta_disable_title":"","ngg_post_thumbnail":0,"footnotes":""},"categories":[30],"tags":[],"class_list":["post-578","post","type-post","status-publish","format-standard","hentry","category-sic-knowledge"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/siliconcarbide.net\/cs\/wp-json\/wp\/v2\/posts\/578","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/siliconcarbide.net\/cs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/siliconcarbide.net\/cs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/siliconcarbide.net\/cs\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/siliconcarbide.net\/cs\/wp-json\/wp\/v2\/comments?post=578"}],"version-history":[{"count":1,"href":"https:\/\/siliconcarbide.net\/cs\/wp-json\/wp\/v2\/posts\/578\/revisions"}],"predecessor-version":[{"id":579,"href":"https:\/\/siliconcarbide.net\/cs\/wp-json\/wp\/v2\/posts\/578\/revisions\/579"}],"wp:attachment":[{"href":"https:\/\/siliconcarbide.net\/cs\/wp-json\/wp\/v2\/media?parent=578"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/siliconcarbide.net\/cs\/wp-json\/wp\/v2\/categories?post=578"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/siliconcarbide.net\/cs\/wp-json\/wp\/v2\/tags?post=578"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}