A szil\u00edciumkarbid (m\u00e1s n\u00e9ven karborundum) szil\u00edcium- \u00e9s sz\u00e9natomokb\u00f3l \u00e1ll\u00f3 szervetlen k\u00e9miai vegy\u00fclet, amely a term\u00e9szetben moissanitk\u00e9nt fordul el\u0151, \u00e9s 1893 \u00f3ta t\u00f6megesen gy\u00e1rtj\u00e1k csiszol\u00f3anyagk\u00e9nt.<\/p>\n
A SiC t\u00f6bb mint 70 krist\u00e1lyos form\u00e1ban l\u00e9tezik, k\u00e9t polimorfra osztva: alfa-szil\u00edciumkarbid (a-SiC) \u00e9s b\u00e9ta-szil\u00edciumkarbid (b-SiC). K\u00eds\u00e9rleti hib\u00e1n bel\u00fcl mindk\u00e9t forma egyidej\u0171leg olvad 10 GPa nyom\u00e1son.<\/p>\n
A szil\u00edciumkarbid rendk\u00edv\u00fcl kem\u00e9ny \u00e9s s\u0171r\u0171 anyag, amelynek sz\u00e1mos alkalmaz\u00e1si ter\u00fclete van. Olyan term\u00e9kekben tal\u00e1lhat\u00f3 meg, mint a csiszol\u00f3pap\u00edr, csiszol\u00f3korongok, v\u00e1g\u00f3szersz\u00e1mok, aut\u00f3ipari alkatr\u00e9szek \u00e9s aut\u00f3ipari t\u0171z\u00e1ll\u00f3 anyagok; emellett kem\u00e9nys\u00e9ge \u00e9s alacsony h\u0151t\u00e1gul\u00e1si r\u00e1t\u00e1ja miatt t\u0171z\u00e1ll\u00f3 anyagk\u00e9nt szolg\u00e1l kemenc\u00e9kben, kemenc\u00e9kben \u00e9s t\u0171z\u00e1ll\u00f3 b\u00e9l\u00e9sekben, valamint t\u00fck\u00f6ranyagk\u00e9nt csillag\u00e1szati t\u00e1vcs\u00f6vekben.<\/p>\n
Edward Goodrich Acheson 1891-ben \u00e1ll\u00edtott el\u0151 el\u0151sz\u00f6r t\u00f6megesen szil\u00edciumkarbidot, amikor egy elektromos kemenc\u00e9ben agyag \u00e9s por\u00edtott koksz (sz\u00e9n) kever\u00e9k\u00e9t hev\u00edtette, \u00e9s \"karborundum\" n\u00e9ven ismert k\u00e9k-fekete anyagot \u00e1ll\u00edtott el\u0151.<\/p>\n
A szil\u00edcium-karbid 5-8 GPa k\u00f6z\u00f6tti nyom\u00e1son t\u00f6rt\u00e9n\u0151 olvad\u00e1s\u00e1nak vizsg\u00e1lata kimutatta, hogy a szil\u00edcium-karbid minden vizsg\u00e1lt nyom\u00e1son kongruens m\u00f3don olvad, \u00e9s olvad\u00e1si g\u00f6rb\u00e9j\u00e9nek negat\u00edv meredeks\u00e9ge -44 + 4 K\/GPa, ami bizony\u00edtja, hogy a s\u0171r\u0171s\u00e9gfunkcion\u00e1l-elm\u00e9let pontosan megj\u00f3solta.<\/p>\n
A szil\u00edciumkarbid (SiC) egy nem oxidos ker\u00e1miaanyag, amely kiv\u00e9teles tulajdons\u00e1gokkal rendelkezik, \u00e9s ez\u00e9rt sz\u00e1mos magas h\u0151m\u00e9rs\u00e9klet\u0171 alkalmaz\u00e1sban hasznos. A SiC kem\u00e9ny \u00e9s rendk\u00edv\u00fcl er\u0151s, polikrist\u00e1lyos test\u00e9nek szil\u00e1rds\u00e1ga ak\u00e1r 27 GPa is lehet; emellett kiv\u00e1l\u00f3 k\u00fasz\u00e1s\u00e1ll\u00f3s\u00e1gi tulajdons\u00e1gokkal \u00e9s alacsony h\u0151t\u00e1gul\u00e1si sebess\u00e9ggel rendelkezik.<\/p>\n
A ker\u00e1mia ker\u00e1mia (CeO2) v\u00edzben nem old\u00f3dik, de old\u00f3dik az olvadt l\u00fag- \u00e9s vasoldatokban, \u00edgy a legkem\u00e9nyebb a fejlett szerkezeti ker\u00e1mi\u00e1k k\u00f6z\u00fcl, ellen\u00e1ll a kop\u00e1snak, a korr\u00f3zi\u00f3nak, az \u00fct\u0151d\u00e9snek \u00e9s a nagy nyom\u00e1son t\u00f6rt\u00e9n\u0151 h\u0151t\u00e1gul\u00e1snak; \u00edgy t\u00f6k\u00e9letesen alkalmas magas h\u0151m\u00e9rs\u00e9klet\u0171 alkalmaz\u00e1sokban, p\u00e9ld\u00e1ul atomreaktorok alkatr\u00e9szeiben val\u00f3 felhaszn\u00e1l\u00e1sra.<\/p>\n
A szil\u00edciumkarbid, k\u00f6zismertebb nev\u00e9n a-SiC, gyakran megtal\u00e1lhat\u00f3 az elektromos j\u00e1rm\u0171vek f\u00e9kjeiben \u00e9s tengelykapcsol\u00f3iban, valamint goly\u00f3\u00e1ll\u00f3 mell\u00e9nyekben, \u00e9s heterog\u00e9n kataliz\u00e1torok hordoz\u00f3anyagak\u00e9nt is haszn\u00e1lj\u00e1k. Ennek az anyagnak az ipari mennyis\u00e9g\u0171 el\u0151\u00e1ll\u00edt\u00e1s\u00e1hoz m\u00e9g mindig elektromos kemenc\u00e9kben finomra \u0151r\u00f6lt koksszal reduk\u00e1lt tiszta kovahomokot haszn\u00e1lnak; a szil\u00edcium-karbid ipari m\u00e9ret\u0171 el\u0151\u00e1ll\u00edt\u00e1sa tov\u00e1bbra is n\u00e9pszer\u0171 v\u00e1laszt\u00e1s a teljes\u00edtm\u00e9nyelektronik\u00e1ban haszn\u00e1lt nagyfesz\u00fclts\u00e9g\u0171 alkalmaz\u00e1sokhoz.<\/p>\n
A szil\u00edciumkarbid, m\u00e1s n\u00e9ven szil\u00edcium-dioxid, egy kem\u00e9ny k\u00e9miai vegy\u00fclet, amely szil\u00edciumb\u00f3l \u00e9s sz\u00e9nb\u0151l \u00e1ll, \u00e9s a term\u00e9szetben moissanit \u00e1sv\u00e1nyk\u00e9nt fordul el\u0151, de 1893 \u00f3ta t\u00f6megesen gy\u00e1rtj\u00e1k por \u00e9s krist\u00e1ly form\u00e1j\u00e1ban, csiszol\u00f3anyagk\u00e9nt \u00e9s goly\u00f3\u00e1ll\u00f3 mell\u00e9ny ker\u00e1mialapk\u00e9nt val\u00f3 felhaszn\u00e1l\u00e1sra. A nagy, egykrist\u00e1lyos szemcs\u00e9k szinterez\u00e9ssel \u00f6sszekapcsolhat\u00f3k, hogy rendk\u00edv\u00fcl kem\u00e9ny szerkezeti ker\u00e1mi\u00e1kat \u00e1ll\u00edtsanak el\u0151; emellett gyakran haszn\u00e1lj\u00e1k szintetikus moissanit dr\u00e1gak\u00f6vek, \u00fagynevezett szintetikus moissanit dr\u00e1gak\u00f6vek k\u00e9sz\u00edt\u00e9s\u00e9re. A szil\u00edcium-karbid f\u00e9lvezet\u0151k\u00e9nt is m\u0171k\u00f6dik; nitrog\u00e9nnel vagy foszforral t\u00f6rt\u00e9n\u0151 adal\u00e9kol\u00e1ssal n-t\u00edpus\u00fa anyagg\u00e1 tehet\u0151; hasonl\u00f3k\u00e9ppen a berillium, a b\u00f3r vagy az alum\u00ednium megv\u00e1ltoztathatja p-t\u00edpus\u00fa anyagg\u00e1 att\u00f3l f\u00fcgg\u0151en, hogy milyen tulajdons\u00e1gai lesznek adal\u00e9kol\u00e1ssal adal\u00e9kol\u00e1ssal n-t\u00edpus\u00fa f\u00e9lvezet\u0151 anyagg\u00e1 v\u00e1ltoztatja.<\/p>\n
A szil\u00edcium-karbidnak t\u00e1g s\u00e1vh\u00e9zaga \u00e9s nagy elektromos t\u00e9rbeli \u00e1tboml\u00e1si szil\u00e1rds\u00e1ga van, ami alkalmass\u00e1 teszi a rendk\u00edv\u00fcl magas h\u0151m\u00e9rs\u00e9kleten vagy fesz\u00fclts\u00e9gen m\u0171k\u00f6d\u0151 elektronikai eszk\u00f6z\u00f6kh\u00f6z. Tov\u00e1bb\u00e1 a termikus sokknak ellen\u00e1ll\u00f3 jellege miatt sz\u00e9les k\u00f6rben alkalmazz\u00e1k. A szil\u00edciumkarbid k\u00fcl\u00f6nb\u00f6z\u0151 (kocka, rombuszos vagy hatsz\u00f6glet\u0171) egys\u00e9gcell\u00e1kban l\u00e9tezik. Ha agyaggal s\u0171r\u00edtik, akkor g\u00e1tolhatj\u00e1k a ny\u00e1k n\u00f6veked\u00e9s\u00e9t, mik\u00f6zben megakad\u00e1lyozz\u00e1k a SiO2 k\u00e9pz\u0151d\u00e9s\u00e9t, amely egy\u00e9bk\u00e9nt cs\u00f6kkenten\u00e9 a rugalmass\u00e1gi modulust. K\u00fcl\u00f6nb\u00f6z\u0151 tanulm\u00e1nyok vizsg\u00e1lt\u00e1k az olvad\u00e1si viselked\u00e9s\u00e9t nagy nyom\u00e1s alatt ab initio molekuladinamikai szimul\u00e1ci\u00f3kkal, amelyek s\u0171r\u0171s\u00e9gfunkcion\u00e1l-elm\u00e9leti szimul\u00e1ci\u00f3kon alapulnak.<\/p>\n
A szil\u00edciumkarbid egy rendk\u00edv\u00fcl kem\u00e9ny \u00e9s merev ker\u00e1miaanyag, amelyet magas h\u0151m\u00e9rs\u00e9klett\u0171r\u0151 k\u00e9pess\u00e9ge, alacsony h\u0151t\u00e1gul\u00e1si egy\u00fctthat\u00f3ja \u00e9s k\u00e9miai reakci\u00f3kkal szembeni ellen\u00e1ll\u00e1sa jellemez. K\u00fcl\u00f6nb\u00f6z\u0151 m\u00e9retekben \u00e9s form\u00e1kban kaphat\u00f3, t\u00f6bbek k\u00f6z\u00f6tt szemcs\u00e9s form\u00e1ban a v\u00e1s\u00e1rl\u00e1shoz, valamint ostyak\u00e9nt, amelyb\u0151l nagy t\u00e1vcs\u00f6vek t\u00fckrei k\u00e9sz\u00edthet\u0151k. A szil\u00edciumkarbid gy\u00e1rt\u00e1si m\u00f3dszerei a k\u00f6zvetlen sz\u00e9nszint\u00e9zist\u0151l a k\u00e9miai g\u0151zf\u00e1zis\u00fa lev\u00e1laszt\u00e1sig terjednek.<\/p>\n
A Debye-h\u0151m\u00e9rs\u00e9klet nyom\u00e1sf\u00fcgg\u00e9s\u00e9nek vizsg\u00e1lata ZB \u00e9s RS SiC-ben 3100+40 K-t\u00f3l 5-8 GPa-ig terjed\u0151 h\u0151m\u00e9rs\u00e9kleten, 3100+40 K-t\u00f3l 5-8 GPa-ig terjed\u0151 h\u0151m\u00e9rs\u00e9kleten, olt\u00e1si k\u00eds\u00e9rletek \u00e9s in situ m\u00e9r\u00e9sek seg\u00edts\u00e9g\u00e9vel t\u00f6rt\u00e9nt, olt\u00e1si k\u00eds\u00e9rletek \u00e9s in situ m\u00e9r\u00e9sek seg\u00edts\u00e9g\u00e9vel. Az eredm\u00e9nyek azt mutatj\u00e1k, hogy k\u00f6rnyezeti nyom\u00e1son mindk\u00e9t Lame-\u00e1lland\u00f3 (l, m) pozit\u00edv, m n\u00f6vekv\u0151 elt\u00e9r\u00e9s\u00e9vel, ami a t\u00f6lt\u00e9s\u00e1tviteli k\u00f6lcs\u00f6nhat\u00e1sokat mag\u00e1ban foglal\u00f3 nem centr\u00e1lis soktest\u0171 er\u0151k er\u0151ss\u00e9g\u00e9nek n\u00f6veked\u00e9s\u00e9re utal magasabb nyom\u00e1son, ami a SiC \u00f6sszenyomhat\u00f3s\u00e1g\u00e1nak mechanikai merevs\u00e9g\u00e9t eredm\u00e9nyezi.<\/p>","protected":false},"excerpt":{"rendered":"
Silicon carbide (also referred to as carborundum) is an inorganic chemical compound composed of silicon and carbon atoms, naturally found […]<\/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":[5],"tags":[],"class_list":["post-66","post","type-post","status-publish","format-standard","hentry","category-product-related"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/siliconcarbideceramic.net\/hu\/wp-json\/wp\/v2\/posts\/66","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/siliconcarbideceramic.net\/hu\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/siliconcarbideceramic.net\/hu\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/hu\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/hu\/wp-json\/wp\/v2\/comments?post=66"}],"version-history":[{"count":1,"href":"https:\/\/siliconcarbideceramic.net\/hu\/wp-json\/wp\/v2\/posts\/66\/revisions"}],"predecessor-version":[{"id":67,"href":"https:\/\/siliconcarbideceramic.net\/hu\/wp-json\/wp\/v2\/posts\/66\/revisions\/67"}],"wp:attachment":[{"href":"https:\/\/siliconcarbideceramic.net\/hu\/wp-json\/wp\/v2\/media?parent=66"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/hu\/wp-json\/wp\/v2\/categories?post=66"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/hu\/wp-json\/wp\/v2\/tags?post=66"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}