Karbid krem\u00edka m\u00e1 v\u010faka svojim vynikaj\u00facim vlastnostiam \u0161irok\u00e9 uplatnenie v priemysle. Patr\u00ed medzi ne jeho odolnos\u0165 vo\u010di kor\u00f3zii, oxid\u00e1cii a tepeln\u00fdm vplyvom.<\/p>\n
Reakt\u00edvne viazan\u00fd SiC sa vyr\u00e1ba procesom spekania infiltr\u00e1ciou tekut\u00e9ho krem\u00edka do por\u00e9znych zelen\u00fdch telies karbidu krem\u00edka a jeho inf\u00faziou pod tlakom. V\u00fdsledn\u00fd materi\u00e1l m\u00e1 n\u00edzku lomov\u00fa h\u00fa\u017eevnatos\u0165.<\/p>\n
Keramika z karbidu krem\u00edka je zn\u00e1ma svoj\u00edm extr\u00e9mne tvrd\u00fdm povrchom, ktor\u00fd poskytuje vynikaj\u00face vlastnosti odolnosti vo\u010di oderu, kor\u00f3zii a teplu. Okrem toho tento materi\u00e1l vykazuje vynikaj\u00face vlastnosti odolnosti vo\u010di oxid\u00e1cii spolu so siln\u00fdmi \u00farov\u0148ami pevnosti pri vysok\u00fdch teplot\u00e1ch, vlastnos\u0165ami chemickej stability, ako aj mechanickej tvrdosti.<\/p>\n
Silik\u00f3nov\u00e9 tesnenia, ktor\u00e9 s\u00fa k dispoz\u00edcii v r\u00f4znych \u0161tandardn\u00fdch ve\u013ekostiach a geometri\u00e1ch pre aplik\u00e1cie v procesn\u00fdch zariadeniach, pon\u00fakaj\u00fa vynikaj\u00facu odolnos\u0165 proti oderu so zn\u00ed\u017een\u00fdm tren\u00edm o sp\u00e1jacie komponenty v tesneniach \u010derpadiel.<\/p>\n
Odolnos\u0165 spekan\u00e9ho karbidu krem\u00edka vo\u010di er\u00f3zii a opotrebovaniu mo\u017eno \u010falej zv\u00fd\u0161i\u0165 pou\u017eit\u00edm karbidov b\u00f3ru alebo volfr\u00e1mu, pri\u010dom tieto \u0161peci\u00e1lne triedy pon\u00fakaj\u00fa lep\u0161iu mechaniku materi\u00e1lu pri zv\u00fd\u0161en\u00fdch teplot\u00e1ch napriek mierne vy\u0161\u0161\u00edm surovin\u00e1m a v\u00fdrobn\u00fdm n\u00e1kladom.<\/p>\n
Reak\u010dn\u00e9 sp\u00e1janie alebo beztlakov\u00e9 spekanie SiC keramiky vytv\u00e1ra r\u00f4zne mikro\u0161trukt\u00fary, pri\u010dom zvolen\u00fd sp\u00f4sob tvarovania ur\u010duje ich kone\u010dn\u00fd v\u00fdsledok. Reak\u010dne sp\u00e1jan\u00fd karbid krem\u00edka pon\u00faka ni\u017e\u0161ie teploty spracovania, vynikaj\u00face tvarov\u00e9 schopnosti a ni\u017e\u0161ie n\u00e1klady ako beztlakov\u00e9 spekanie SiC; jeho pevnos\u0165 pri vysok\u00fdch teplot\u00e1ch a pevnos\u0165 v ohybe je v\u0161ak ni\u017e\u0161ia v porovnan\u00ed s pevnos\u0165ou, ktor\u00fa produkuje beztlakov\u00e9 spekanie SiC; preto je reak\u010dne sp\u00e1jan\u00fd karbid krem\u00edka vhodnej\u0161\u00ed pre aplik\u00e1cie, ktor\u00e9 nevy\u017eaduj\u00fa od keramick\u00e9ho materi\u00e1lu maxim\u00e1lny v\u00fdkon.<\/p>\n
Keramika z karbidu krem\u00edka sa m\u00f4\u017ee pochv\u00e1li\u0165 jednou z najvy\u0161\u0161\u00edch hodn\u00f4t odolnosti proti kor\u00f3zii spomedzi v\u0161etk\u00fdch keram\u00edk a v\u010faka svojej pozoruhodnej tvrdosti, pevnosti, tepelnej vodivosti a odolnosti proti opotrebovaniu odol\u00e1va aj n\u00e1ro\u010dn\u00fdm chemick\u00fdm podmienkam. Okrem toho karbid krem\u00edka pon\u00faka vynikaj\u00facu odolnos\u0165 vo\u010di oxid\u00e1cii, ako aj vlastnosti odolnosti vo\u010di opotrebovaniu.<\/p>\n
Spekan\u00fd karbid krem\u00edka (SSiC) sa vyr\u00e1ba lisovan\u00edm a spekan\u00edm (zahrievan\u00edm) jemnozrnn\u00e9ho pr\u00e1\u0161ku SiC s neoxidov\u00fdmi spekan\u00fdmi pomocn\u00fdmi l\u00e1tkami do pastovitej zmesi, ktor\u00e1 sa potom m\u00f4\u017ee zhutni\u0165 alebo vytvarova\u0165 pod\u013ea potreby pou\u017eitia alebo vytla\u010di\u0165 cez lisovacie formy do r\u00farok zo spekan\u00e9ho karbidu krem\u00edka.<\/p>\n
Reakt\u00edvne spekanie zah\u0155\u0148a mie\u0161anie viacprvkov\u00fdch eutektick\u00fdch oxidov (napr\u00edklad Y2O3-Al2O3) pri n\u00edzkej eutektickej teplote s cie\u013eom vytvori\u0165 kvapaln\u00fa f\u00e1zu pre pohyb \u010dast\u00edc SiC, dif\u00faziu a prenos hmoty po\u010das zhut\u0148ovania do spekan\u00fdch keramick\u00fdch v\u00fdrobkov s presn\u00fdmi rozmermi; m\u00e1 v\u0161ak nev\u00fdhody, ako je drah\u00e1 spotreba surov\u00edn a n\u00e1klady na energiu, ako aj kor\u00f3zne spr\u00e1vanie po\u010das zhut\u0148ovania, ktor\u00e9 sa mus\u00ed starostlivo riadi\u0165, aby sa dosiahli najlep\u0161ie vlastnosti keramiky SiC.<\/p>\n
Karbid krem\u00edka odol\u00e1va vysok\u00fdm teplot\u00e1m, \u010do z neho rob\u00ed vynikaj\u00faci materi\u00e1l na pou\u017eitie v zariadeniach na chemick\u00e9 spracovanie, ako s\u00fa pece. Okrem toho je odoln\u00fd vo\u010di chemickej kor\u00f3zii, tak\u017ee vydr\u017e\u00ed teploty a\u017e do 1 900 \u00b0C a z\u00e1rove\u0148 sa m\u00f4\u017ee pochv\u00e1li\u0165 skvel\u00fdmi vlastnos\u0165ami mechanickej tvrdosti.<\/p>\n
Reak\u010dne viazan\u00e1 SiC keramika sa vyr\u00e1ba z por\u00e9znych uhl\u00edkov\u00fdch surov\u00edn v kombin\u00e1cii s roztaven\u00fdm krem\u00edkom a formuje sa met\u00f3dami, ako je such\u00e9 lisovanie, odlievanie a vytl\u00e1\u010danie. \u010casto sa pou\u017e\u00edvaj\u00fa v kompozitn\u00fdch pancierov\u00fdch syst\u00e9moch proti balistick\u00fdm hrozb\u00e1m.<\/p>\n
Beztlakovo spekan\u00fd karbid krem\u00edka (PSiC) je modern\u00fd materi\u00e1l s v\u00fdnimo\u010dn\u00fdmi vlastnos\u0165ami z h\u013eadiska pevnosti, tvrdosti a tepelnej vodivosti, ako aj odolnosti vo\u010di kor\u00f3zii, oxid\u00e1cii a oh\u00fdbaniu - ide\u00e1lny pre komponenty, ako s\u00fa d\u00fdzy, tesnenia a opotrebovate\u013en\u00e9 kr\u00fa\u017eky.<\/p>\n
Na zv\u00fd\u0161enie \u00fa\u010dinnosti spekania PSiC mo\u017eno vytvori\u0165 kvapaln\u00fa f\u00e1zu pridan\u00edm jedn\u00e9ho alebo viacer\u00fdch viacprvkov\u00fdch eutektick\u00fdch oxidov, ako napr\u00edklad Y2O3-Al2O3, ktor\u00e9 maj\u00fa n\u00edzke eutektick\u00e9 body a podporuj\u00fa pohyb, dif\u00faziu a preskupenie \u010dast\u00edc SiC, \u010do vedie k zhutneniu produktu. V\u00fdsledkom je, \u017ee vyroben\u00e1 SiC keramika m\u00e1 vynikaj\u00face vlastnosti pevnosti v ohybe a teplotnej odolnosti.<\/p>\n
Spekan\u00fd karbid krem\u00edka sa m\u00f4\u017ee pochv\u00e1li\u0165 vysokou pevnos\u0165ou, ktor\u00e1 zost\u00e1va relat\u00edvne kon\u0161tantn\u00e1 pri vysok\u00fdch teplot\u00e1ch, \u010do z neho rob\u00ed vynikaj\u00facu vo\u013ebu materi\u00e1lu pre mnoh\u00e9 aplik\u00e1cie. Okrem toho je v\u010faka svojej odolnosti vo\u010di chemickej kor\u00f3zii vhodn\u00fd do mnoh\u00fdch priemyseln\u00fdch prostred\u00ed.<\/p>\n
Na druhej strane, karbid krem\u00edka viazan\u00fd reakciou (RBSiC) sa vytv\u00e1ra infiltr\u00e1ciou roztaven\u00e9ho krem\u00edka do por\u00e9znych uhl\u00edkov\u00fdch alebo grafitov\u00fdch predliskov a vytvoren\u00edm por\u00e9znych oblast\u00ed medzi ich \u0161trukt\u00farami. RBSiC m\u00e1 ni\u017e\u0161iu pevnos\u0165 a tvrdos\u0165 ako SSiC, ale pon\u00faka vy\u0161\u0161iu odolnos\u0165 vo\u010di chemick\u00fdm a tepeln\u00fdm \u0161okom.<\/p>\n
Spekanie umo\u017e\u0148uje vyr\u00e1ba\u0165 keramick\u00e9 v\u00fdrobky s presn\u00fdmi rozmermi a hustotou, ale m\u00e1 aj svoje nev\u00fdhody: vysok\u00e9 teploty spekania m\u00f4\u017eu sp\u00f4sobi\u0165, \u017ee sa po\u010das zhut\u0148ovania zmr\u0161\u0165uj\u00fa; okrem toho m\u00f4\u017ee tento proces sp\u00f4sobi\u0165 trhliny v materi\u00e1li, ktor\u00e9 ved\u00fa k nerovnomern\u00e9mu chemick\u00e9mu zlo\u017eeniu alebo hustote, \u010do by mohlo ma\u0165 vplyv na v\u00fdkon pri vystaven\u00ed oxida\u010dn\u00e9mu alebo koroz\u00edvnemu prostrediu. V\u00e4\u010d\u0161ina v\u00fdskumn\u00edkov preto vol\u00ed spekanie v kvapalnej f\u00e1ze, ktor\u00e9 je z\u00e1rove\u0148 \u0161etrnej\u0161ie k \u017eivotn\u00e9mu prostrediu.<\/p>\n
Karbid krem\u00edka je jedn\u00fdm z najtvrd\u0161\u00edch materi\u00e1lov na Zemi a jedn\u00fdm z najpevnej\u0161\u00edch. V\u010faka tejto kombin\u00e1cii je odoln\u00fd vo\u010di kor\u00f3zii, oderu a tepeln\u00fdm \u0161okom a z\u00e1rove\u0148 pon\u00faka dobr\u00fa odolnos\u0165 proti opotrebovaniu a n\u00edzke klzn\u00e9 trenie pri pou\u017eit\u00ed s mnoh\u00fdmi r\u00f4znymi spojovac\u00edmi materi\u00e1lmi.<\/p>\n
Spekan\u00e1 SiC keramika dosahuje svoju vysok\u00fa pevnos\u0165 tvorbou siln\u00fdch spekan\u00fdch v\u00e4zieb medzi \u010dasticami SiC. Beztlakov\u00e9 spekanie alebo izostatick\u00e9 lisovanie karbidu krem\u00edka za tepla vytv\u00e1ra v\u00fdrobky prakticky bez p\u00f3rov, \u010do \u010falej zlep\u0161uje mechanick\u00e9 vlastnosti keramick\u00fdch v\u00fdrobkov.<\/p>\n
Reak\u010dne viazan\u00fd karbid krem\u00edka (RSIC) m\u00e1 v porovnan\u00ed s HPSIC alebo HIPSIC otvorenej\u0161iu p\u00f3rovitos\u0165 a hrub\u0161iu \u0161trukt\u00faru z\u0155n, \u010do zni\u017euje jeho pevnos\u0165 v ohybe a rob\u00ed ho menej vhodn\u00fdm pre vysokoteplotn\u00e9 aplik\u00e1cie.<\/p>\n
Priamo spekan\u00fd karbid krem\u00edka m\u00e1 jemnej\u0161ie zrn\u00e1 ako RSIC, a preto je odolnej\u0161\u00ed vo\u010di oxid\u00e1cii, tak\u017ee je drah\u0161\u00ed ako jeho n\u00e1protivok, ale poskytuje vynikaj\u00face vlastnosti odolnosti vo\u010di oderu, teplu a vysok\u00fdm teplot\u00e1m, v\u010faka ktor\u00fdm je ide\u00e1lny pre tesnenia \u010derpadiel alebo in\u00e9 n\u00e1ro\u010dn\u00e9 vysokoteplotn\u00e9 aplik\u00e1cie. Priamo spekan\u00fd karbid krem\u00edka sa be\u017ene \u0161pecifikuje pre aplik\u00e1cie tesnen\u00ed \u010derpadiel, ktor\u00e9 si vy\u017eaduj\u00fa vynikaj\u00facu pevnos\u0165 pri vysok\u00fdch teplot\u00e1ch, ako aj vynikaj\u00face pevnostn\u00e9 vlastnosti pri vysok\u00fdch teplot\u00e1ch.<\/p>","protected":false},"excerpt":{"rendered":"
Silicon carbide has an array of applications in industry due to its excellent properties. These include its resistance against corrosion, oxidation and thermal impact. React-bonded SiC is produced through the sintering process by infiltrating liquid silicon into porous green bodies of silicon carbide and infusing it under pressure. The final material has low fracture toughness. […]<\/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-91","post","type-post","status-publish","format-standard","hentry","category-knowledge"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/ceramicatijolart.com\/sk\/wp-json\/wp\/v2\/posts\/91","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ceramicatijolart.com\/sk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ceramicatijolart.com\/sk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ceramicatijolart.com\/sk\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ceramicatijolart.com\/sk\/wp-json\/wp\/v2\/comments?post=91"}],"version-history":[{"count":1,"href":"https:\/\/ceramicatijolart.com\/sk\/wp-json\/wp\/v2\/posts\/91\/revisions"}],"predecessor-version":[{"id":92,"href":"https:\/\/ceramicatijolart.com\/sk\/wp-json\/wp\/v2\/posts\/91\/revisions\/92"}],"wp:attachment":[{"href":"https:\/\/ceramicatijolart.com\/sk\/wp-json\/wp\/v2\/media?parent=91"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ceramicatijolart.com\/sk\/wp-json\/wp\/v2\/categories?post=91"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ceramicatijolart.com\/sk\/wp-json\/wp\/v2\/tags?post=91"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}