Carbura de siliciu legat\u0103 prin reac\u021bie (RBSC) este un material ceramic extrem de dur \u0219i puternic, cu rezisten\u021b\u0103 mecanic\u0103 superioar\u0103, rezisten\u021b\u0103 la impact, stabilitate chimic\u0103 \u0219i formabilitate, ceea ce \u00eel face potrivit pentru diverse aplica\u021bii.<\/p>\n
RB-SiC ofer\u0103 o duritate mai sc\u0103zut\u0103 \u00een compara\u021bie cu carbura de siliciu sinterizat\u0103, dar este mai u\u0219or \u0219i mai pu\u021bin costisitor de fabricat, av\u00e2nd \u00een acela\u0219i timp propriet\u0103\u021bi excelente de rezisten\u021b\u0103 la \u0219ocurile termice.<\/p>\n
Procesul RMI utilizeaz\u0103 particule de a-SiC \u00eencorporate \u00eentr-o preform\u0103 de carbon poros (G0), \u00eenainte de infiltrarea cu siliciu lichid pentru a ob\u021bine carbur\u0103 de siliciu legat\u0103 prin reac\u021bie. Cu toate acestea, din p\u0103cate, siliciul lichid poate cauza \u00eenfundarea porilor din cauza procesului de infiltrare \u0219i, prin urmare, \u00een acest studiu, carbonul multifazic a fost utilizat ca un antidot \u00eempotriva acestei probleme \u0219i pentru a \u00eembun\u0103t\u0103\u021bi propriet\u0103\u021bile mecanice ale RB-SiC.<\/p>\n
Carbonul multifazic a fost compus din negru de fum amorf fin \u0219i carbon micro-sferic grosier. Atunci c\u00e2nd este infiltrat cu siliciu lichid, carbonul micro-sferic este consumat, \u00een timp ce carbonul amorf poate sc\u0103pa din pori pentru a preveni reac\u021biile de umplere a porilor care \u00eei \u00eenfund\u0103 - astfel, atunci c\u00e2nd a fost observat pe probele P10F90, P20F80 \u0219i P30F70, v\u00e2rful caracteristic nu a fost prezent, suger\u00e2nd c\u0103 carbonul multifazic a contribuit la evitarea acestei probleme \u0219i la \u00eembun\u0103t\u0103\u021birea rezisten\u021bei la \u00eencovoiere pe m\u0103sur\u0103 ce temperatura de infiltrare \u0219i timpul de \u00eenmuiere au crescut.<\/p>\n
Carbura de siliciu RB este produs\u0103 prin infiltrarea siliciului topit \u00eentr-o preform\u0103 poroas\u0103 de carbon sau grafit, unde reac\u021bioneaz\u0103 cu carbonul pentru a forma SiC \u0219i creeaz\u0103 un material ceramic excep\u021bional rezistent la uzur\u0103, impact \u0219i substan\u021be chimice, care vine \u00een diferite forme \u0219i dimensiuni, de la forme simple de conuri \u0219i man\u0219oane la piese de inginerie mai mari pentru industria minier\u0103 sau de prelucrare.<\/p>\n
Compozi\u021bia unui precursor compozit, \u00een special raportul dintre PF \u0219i FA, influen\u021beaz\u0103 viteza de reac\u021bie dintre carbon \u0219i siliciul lichid \u00een timpul pirolizei la temperatur\u0103 ridicat\u0103. Carbonul multifazic \u00eembun\u0103t\u0103\u021be\u0219te penetrarea siliciului lichid prin porii preformelor poroase; sursele de carbon gradate ajut\u0103 la controlul con\u021binutului de b-SiC \u0219i de Si liber.<\/p>\n
Rezisten\u021ba la flexiune \u0219i modulul de elasticitate ale carburii de siliciu RB pot fi crescute substan\u021bial prin sortarea atent\u0103 a sursei de carbon, datorit\u0103 elimin\u0103rii suprafe\u021belor netede ale gr\u0103un\u021bilor negri \u0219i albi care provoac\u0103 fractura intergranular\u0103 \u00een timpul \u00eendoirii.<\/p>\n
Propriet\u0103\u021bile termice ale ceramicii din carbur\u0103 de siliciu legat\u0103 prin reac\u021bie depind de tipul \u0219i de propor\u021bia lipirii. Carbur\u0103 de siliciu legat\u0103 prin reac\u021bie (RBSC), infiltrat\u0103 cu particule de siliciu metalic, infiltrat\u0103 \u00een preforme de carbon sau grafit care nu se contract\u0103 \u00een timpul acestui proces; astfel, pot fi create piese cu dimensiuni foarte precise.<\/p>\n
Dup\u0103 infiltrarea cu RBSC, acesta este supus nitruirii la temperaturi ridicate. Aceasta transform\u0103 siliciul metalic \u00een nitrur\u0103 de SiC \u0219i umple toate spa\u021biile cu pori r\u0103mase cu material de re\u021bea de carbur\u0103 de siliciu. XRD arat\u0103 c\u0103 aceast\u0103 form\u0103 con\u021bine diamant, a-SiC, b-SiC, Si \u0219i SiO2, \u00een timp ce SEM arat\u0103 straturi de grafit, precum \u0219i carbon amorf.<\/p>\n
Datorit\u0103 stratului de grafit prezent, RBSC prezint\u0103 valori k mai mici dec\u00e2t SiC sinterizat, dep\u0103\u0219indu-le totu\u0219i pe cele ale NSIC. \u00cen plus, a dep\u0103\u0219it semnificativ ceramica pe baz\u0103 de SiO2 \u00een ceea ce prive\u0219te rezisten\u021ba la coroziune, rezisten\u021ba la temperaturi ridicate, rezisten\u021ba la \u0219ocuri termice \u0219i capacitatea de absorb\u021bie a \u0219ocurilor termice.<\/p>\n
Carbura de siliciu legat\u0103 prin reac\u021bie ofer\u0103 propriet\u0103\u021bi electrice excelente, cum ar fi rezisten\u021ba specific\u0103 sc\u0103zut\u0103 \u0219i conductivitatea termic\u0103 ridicat\u0103. Aceste atribute \u00eel fac o alegere excelent\u0103 de material pentru elementele de \u00eenc\u0103lzire electric\u0103. \u00cen plus, iner\u021bia sa chimic\u0103 \u0219i rezisten\u021ba la oxidare \u00eel fac potrivit pentru termocuplurile cuptoarelor, v\u00e2rfurile arz\u0103toarelor, c\u0103r\u0103mizile de control \u0219i muflele din cuptoare; rezisten\u021ba sa superioar\u0103 la \u0219ocurile termice \u00eel fac, de asemenea, potrivit ca mobilier \u00een cuptoare.<\/p>\n
SiC legat prin reac\u021bie poate fi creat prin procesul de amestecare a amestecurilor intime fin divizate de sic \u0219i carbon cu plastifiant, apoi modelarea \u0219i arderea plastifiantului \u00eenainte de infiltrarea acestuia cu siliciu lichid sau gazos. Aceast\u0103 reac\u021bie permite siliciului s\u0103 se lege de carbon pentru a produce mai mult carbur\u0103 de siliciu, care reac\u021bioneaz\u0103 apoi cu carbura de siliciu ini\u021bial\u0103 pentru a forma un compozit format din a-SiC, b-SiC \u0219i Si rezidual.<\/p>\n
La momentul infiltr\u0103rii, se afirm\u0103 c\u0103 granulele de a-SiC \u0219i b-SiC formate \u00een timpul reac\u021biei sunt dispersate uniform \u00een preforma poroas\u0103 f\u0103r\u0103 aglomer\u0103ri, probabil datorit\u0103 faptului c\u0103 canalele capilare nu sunt blocate de particulele de b-SiC nou formate.<\/p>","protected":false},"excerpt":{"rendered":"
Reaction bonded silicon carbide (RBSC) is an exceptionally hard and strong ceramic material with superior mechanical strength, impact resistance, chemical […]<\/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-36","post","type-post","status-publish","format-standard","hentry","category-product-related"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/siliconcarbideceramic.net\/ro\/wp-json\/wp\/v2\/posts\/36","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/siliconcarbideceramic.net\/ro\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/siliconcarbideceramic.net\/ro\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/ro\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/ro\/wp-json\/wp\/v2\/comments?post=36"}],"version-history":[{"count":1,"href":"https:\/\/siliconcarbideceramic.net\/ro\/wp-json\/wp\/v2\/posts\/36\/revisions"}],"predecessor-version":[{"id":37,"href":"https:\/\/siliconcarbideceramic.net\/ro\/wp-json\/wp\/v2\/posts\/36\/revisions\/37"}],"wp:attachment":[{"href":"https:\/\/siliconcarbideceramic.net\/ro\/wp-json\/wp\/v2\/media?parent=36"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/ro\/wp-json\/wp\/v2\/categories?post=36"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/ro\/wp-json\/wp\/v2\/tags?post=36"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}