Sil\u012bcija karb\u012bds (SiC) ir neorganisks keramikas materi\u0101ls, ko pla\u0161i izmanto meh\u0101niski un termiski sare\u017e\u0123\u012btos lietojumos un kas ciet\u012bbas zi\u0146\u0101 atpaliek tikai no bora karb\u012bda un dimanta.<\/p>\n
Karborundu pirmo reizi atkl\u0101ja amerik\u0101\u0146u izgudrot\u0101js Edvards G. A\u010dons, 1891. gad\u0101 m\u0113\u0123inot ra\u017eot m\u0101ksl\u012bgos dimantus, un kop\u0161 t\u0101 laika tas ir k\u013cuvis par neaizst\u0101jamu griez\u0113jinstrumentu un ugunsiztur\u012bgo oder\u0113jumu sast\u0101vda\u013cu.<\/p>\n
Sil\u012bcija karb\u012bdam piem\u012bt iespaid\u012bgas fizik\u0101l\u0101s \u012bpa\u0161\u012bbas, tom\u0113r tas bie\u017ei tiek nepareizi saprasts un interpret\u0113ts. Bie\u017ei vien ciet\u012bbu jauc ar iztur\u012bbu; paties\u012bb\u0101 t\u0101 dr\u012bz\u0101k attiecas uz materi\u0101lu iztur\u012bbu pret deform\u0101ciju, nevis stingr\u012bbu vai st\u012bvumu.<\/p>\n
Materi\u0101lu ciet\u012bbu nosaka to mikrotr\u016bdam\u012bba jeb maza m\u0113roga b\u012bdes modulis visos virzienos, nevis ciet\u012bba jeb Junga modulis, kas atkar\u012bgs no da\u017e\u0101diem faktoriem, tostarp \u0123eometrijas un \u0137\u012bmisk\u0101 sast\u0101va; piem\u0113ram, sil\u012bcija karb\u012bds ir daudz ciet\u0101ks nek\u0101 dimants, bet maz\u0101k ciets nek\u0101, piem\u0113ram, osmijs vai volframs.<\/p>\n
Ciet\u0101ki materi\u0101li m\u0113dz b\u016bt iztur\u012bg\u0101ki pret boj\u0101jumiem, ta\u010du maz\u0101k elast\u012bgi vai elast\u012bgi nek\u0101 m\u012bkst\u0101ki materi\u0101li - t\u0101d\u0113\u013c reiz\u0113m ciet\u012bba un ciet\u012bba tiek lietotas savstarp\u0113ji aizvietojami.<\/p>\n
Sil\u012bcija karb\u012bds ir visciet\u0101kais no visiem krist\u0101liskajiem savienojumiem, lai gan nav tik ciets k\u0101 dimants. Sil\u012bcija karb\u012bdu r\u016bpnieciski ra\u017eo k\u0101 abraz\u012bvu un citos metalur\u0123ijas un ugunsiztur\u012bgos izstr\u0101d\u0101jumos, k\u0101 ar\u012b keramikas ra\u017eo\u0161an\u0101, un to var atrast ar\u012b k\u0101 sint\u0113tisko moisan\u012bta rotaslietu alternat\u012bvu dabiskajiem d\u0101rgakme\u0146iem.<\/p>\n
Sil\u012bcija karb\u012bdu saturo\u0161iem kompoz\u012btmateri\u0101liem ciet\u012bba palielin\u0101s proporcion\u0101li SiC masas procentam, jo tie ir iestr\u0101d\u0101ti matric\u0101 un ir iztur\u012bg\u0101ki pret boj\u0101jumiem un b\u012bdes sp\u0113kiem.<\/p>\n
Sil\u012bcija karb\u012bdam piem\u012bt augsta siltumvad\u012btsp\u0113ja, kas noz\u012bm\u0113, ka tas viegli p\u0101rvada siltumu. Tas notiek, pateicoties molekulu vibr\u0101cijai un saskarei starp molekul\u0101m materi\u0101l\u0101; temperat\u016bras gradientiem vis\u0101 materi\u0101la biezum\u0101, t\u0101pat k\u0101 t\u0101 sast\u0101vda\u013cu bl\u012bvumam un krist\u0101liskajai strukt\u016brai, ir b\u016btiska noz\u012bme \u0161aj\u0101 p\u0101rnes\u0113.<\/p>\n
Siltumvad\u012btsp\u0113ja ir b\u016btiska \u012bpa\u0161\u012bba, lai ra\u017eotu modernu keramiku, piem\u0113ram, t\u0101du, ko izmanto automobi\u013cu bremz\u0113s un saj\u016bgos, kas \u013cauj \u0161iem materi\u0101liem darboties augst\u0101k\u0101 temperat\u016br\u0101, nezaud\u0113jot to meh\u0101nisk\u0101s \u012bpa\u0161\u012bbas. Keramiku pla\u0161i izmanto ar\u012b k\u0101 lo\u017eu necaurlaid\u012bgu vestu materi\u0101lu, jo t\u0101s iztur\u012bba sp\u0113j iztur\u0113t \u0101rk\u0101rt\u012bgi lielu sp\u0113ku, nesal\u016bstot.<\/p>\n
SiC augst\u0101 elektrovad\u012btsp\u0113ja \u013cauj pusvad\u012bt\u0101jiem, kas izgatavoti no SiC, darboties daudz augst\u0101k\u0101s frekvenc\u0113s un temperat\u016br\u0101s nek\u0101 sil\u012bcija tranzistori un diodes, t\u0101d\u0113j\u0101di samazinot ener\u0123ijas zudumus un vienlaikus palielinot uzticam\u012bbu.<\/p>\n
Sil\u012bcija karb\u012bda \u0137\u012bmiskais sast\u0101vs padara to ar\u012b par \u013coti stabilu materi\u0101lu, kas ir iztur\u012bgs pret koroziju, padarot to par vienu no iztur\u012bg\u0101kaj\u0101m r\u016bpnieciskaj\u0101m un metalur\u0123iskaj\u0101m keramik\u0101m, kas pieejamas m\u016bsdien\u0101s. Tas var lepoties ar lielisku iztur\u012bbu pret t\u0101d\u0101m \u0137\u012bmisk\u0101m viel\u0101m k\u0101 s\u0101lssk\u0101be, s\u0113rsk\u0101be un fluor\u016bde\u0146ra\u017esk\u0101be, k\u0101 ar\u012b pret koncentr\u0113t\u0101m b\u0101z\u0113m, piem\u0113ram, n\u0101trija hidroks\u012bdu. Turkl\u0101t sil\u012bcija karb\u012bdu var pat kaus\u0113t augst\u0101 temperat\u016br\u0101, lai veidotu stipras saites ar stiklu vai citiem trausliem materi\u0101liem, piem\u0113ram, keramiku.<\/p>\n
SiC elektrovad\u012btsp\u0113ja padara to par nenov\u0113rt\u0113jamu materi\u0101lu ener\u0123ijas lietojumos, jo \u012bpa\u0161i tajos, kuros izmanto lielu str\u0101vas daudzumu. Pateicoties t\u0101 iespaid\u012bgaj\u0101m elektrovad\u012btsp\u0113jas \u012bpa\u0161\u012bb\u0101m, SiC ir k\u013cuvis par dz\u012bvotsp\u0113j\u012bgu alternat\u012bvu sil\u012bcija pusvad\u012bt\u0101jiem t\u0101diem sare\u017e\u0123\u012btiem lietojumiem k\u0101 elektroautomobi\u013cu energoelektronika un instrumenti uz Marsa vai Veneras zond\u0113m (Mantooth, Zetterling & Rusu).<\/p>\n
SiC augsto elektrovad\u012btsp\u0113ju var izskaidrot ar t\u0101 pla\u0161o joslas spraugu. Plaisa starp valences un vad\u012btsp\u0113jas josl\u0101m nosaka, vai materi\u0101ls ir vai nu vad\u012bt\u0101js, vai izolators; ar pla\u0161u plaisu elektroni var br\u012bvi p\u0101rvietoties no valences joslas uz vad\u012btsp\u0113jas joslu, savuk\u0101rt izolatoram \u0161\u012bs plaisas \u0161\u0137\u0113rso\u0161anai ir nepiecie\u0161ams p\u0101r\u0101k liels ener\u0123ijas daudzums.<\/p>\n
\u0136\u012bmisk\u0101 tvaiku infiltr\u0101cija (CVI) vai polim\u0113ru impregn\u0113\u0161ana-pirol\u012bze (PIP) n tipa SiC matric\u0101 paaugstin\u0101t\u0101 temperat\u016br\u0101 palielina elektrisko vad\u012btsp\u0113ju par div\u0101m l\u012bdz trim k\u0101rt\u0101m, jo veidojas krist\u0101li ar zem\u0101k\u0101m joslu atstarp\u0113m nek\u0101 t\u012brs sil\u012bcija karb\u012bds. \u0160o palielin\u0101jumu var saist\u012bt ar jaunu SiC krist\u0101lu veido\u0161anos ar liel\u0101ku elektrisko vad\u012btsp\u0113ju.<\/p>\n
Si-SiC materi\u0101la elektrovad\u012btsp\u0113ja ir no 105 l\u012bdz 107 Ohm*cm, jo t\u0101 zemais termisk\u0101s izple\u0161an\u0101s koeficients un elektrovad\u012btsp\u0113ja ir 105-107 Ohm*cm uz cm kvadr\u0101tmetru, t\u0101p\u0113c tas ir piem\u0113rots lietojumiem, kur nepiecie\u0161ama liela str\u0101va, temperat\u016bra, iztur\u012bba pret eroziju un aizsardz\u012bba pret koroziju. \u0160o \u012bpa\u0161\u012bbu kombin\u0101cija padara Si-SiC par ide\u0101lu kandid\u0101tu.<\/p>\n
Sil\u012bcija karb\u012bds sast\u0101v no oglek\u013ca un sil\u012bcija atomiem, kas sak\u0101rtoti \u010detrpus\u012bg\u0101s strukt\u016br\u0101s, kuras savieno stipras saites, kas veido t\u0101 krist\u0101lisko strukt\u016bru. \u0160\u012bs stipr\u0101s saites pie\u0161\u0137ir sil\u012bcija karb\u012bdam \u0101rk\u0101rt\u012bgi cietu un iztur\u012bgu virsmu, kas ir ar\u012b \u0137\u012bmiski iztur\u012bga; t\u0101 iztur\u012bba aizsarg\u0101 to ar\u012b pret sk\u0101bes iedarb\u012bbu, k\u0101 ar\u012b termisko triecienu l\u012bdz pat 1600 gr\u0101du temperat\u016br\u0101. Turkl\u0101t t\u0101 lielisk\u0101 iztur\u012bba pret trieciena boj\u0101jumiem padara to piem\u0113rotu lietojumiem, kur b\u016btisks faktors ir fiziskais nodilums, piem\u0113ram, smidzin\u0101\u0161anas sprausl\u0101m, str\u016bklas sprausl\u0101m vai ciklonu sast\u0101vda\u013c\u0101m.<\/p>\n
Keramikas nanoda\u013ci\u0146as ir viens no viegl\u0101kajiem, iztur\u012bg\u0101kajiem un ciet\u0101kajiem pieejamajiem keramikas materi\u0101liem. Tam piem\u012bt izcilas elektrisk\u0101s \u012bpa\u0161\u012bbas, teicama siltumvad\u012btsp\u0113ja un zems termisk\u0101s izple\u0161an\u0101s koeficients; turkl\u0101t tas k\u0101 pusvad\u012bt\u0101ju materi\u0101ls ir iztur\u012bgs pret augst\u0101m temperat\u016br\u0101m.<\/p>\n
Sil\u012bcija karb\u012bds ir pusvad\u012bt\u0101js ar pla\u0161u joslas spraugu, t\u0101p\u0113c tas ir piem\u0113rots energoelektronikai. T\u0101 pretest\u012bba spriegumam ir 10 reizes liel\u0101ka nek\u0101 parastajam sil\u012bcijam, un tas ir p\u0101r\u0101ks par gallija nitr\u012bdu sist\u0113m\u0101s, kas darbojas pie lieliem \u0101trumiem vai temperat\u016br\u0101m.<\/p>\n
Sint\u0113tisko dimantu ra\u017eo galvenok\u0101rt izmanto\u0161anai par abraz\u012bvu; tom\u0113r sint\u0113tisko dimantu var izmantot ar\u012b citos veidos, piem\u0113ram, lapid\u0101rij\u0101. Sint\u0113tisko dimantu t\u0101 ilgm\u016b\u017e\u012bbas un notur\u012bbas pret abraz\u012bvu d\u0113\u013c m\u016bsdienu lapid\u0101ri bie\u017ei izmanto k\u0101 sast\u0101vda\u013cu, jo tas ir iztur\u012bgs pret nodilumu un nodilumiztur\u012bbu. Turkl\u0101t sint\u0113tisko dimantu var izmantot ar\u012b k\u0101 abraz\u012bvu sl\u012bp\u0113\u0161anas instrumentos, automobi\u013cu deta\u013c\u0101s un ugunsiztur\u012bgos materi\u0101los, k\u0101 ar\u012b tas ir ciets, iztur\u012bgs un noder\u012bgs kombin\u0101cij\u0101 ar t\u0101diem materi\u0101liem k\u0101 t\u0113rauds un volframa karb\u012bds, lai uzlabotu rezult\u0101tus apstr\u0101des procesos, kombin\u0113jot to ar citiem cietiem un iztur\u012bgiem materi\u0101liem, piem\u0113ram, t\u0113raudu un volframa karb\u012bdu.<\/p>","protected":false},"excerpt":{"rendered":"
Silicon carbide (SiC) is an inorganic ceramic material widely used in mechanically and thermally demanding applications, second only to boron carbide and diamond in terms of hardness. Carborundum was first discovered by American inventor Edward G. Acheson while trying to produce artificial diamonds in 1891 and has become an indispensable component in cutting tools and […]<\/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-308","post","type-post","status-publish","format-standard","hentry","category-knowledge"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/ceramicatijolart.com\/lv\/wp-json\/wp\/v2\/posts\/308","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ceramicatijolart.com\/lv\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ceramicatijolart.com\/lv\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ceramicatijolart.com\/lv\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ceramicatijolart.com\/lv\/wp-json\/wp\/v2\/comments?post=308"}],"version-history":[{"count":1,"href":"https:\/\/ceramicatijolart.com\/lv\/wp-json\/wp\/v2\/posts\/308\/revisions"}],"predecessor-version":[{"id":309,"href":"https:\/\/ceramicatijolart.com\/lv\/wp-json\/wp\/v2\/posts\/308\/revisions\/309"}],"wp:attachment":[{"href":"https:\/\/ceramicatijolart.com\/lv\/wp-json\/wp\/v2\/media?parent=308"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ceramicatijolart.com\/lv\/wp-json\/wp\/v2\/categories?post=308"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ceramicatijolart.com\/lv\/wp-json\/wp\/v2\/tags?post=308"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}