Sinterimi i karbhidit t\u00eb silikonit qeramik q\u00eb p\u00ebrmban element\u00ebt C dhe B4C si ndihm\u00ebs sinterimi \u00ebsht\u00eb sinterim n\u00eb faz\u00eb t\u00eb ngurt\u00eb, dhe procesi i sinterimit kontrollohet kryesisht nga mekanizmi i difuzionit, me nj\u00eb temperatur\u00eb optimale sinterimi prej 2150 \u00b0C. Procesi i sinterimit \u00ebsht\u00eb i thjesht\u00eb dhe i leht\u00eb p\u00ebr t'u kontrolluar. Shtoni sasin\u00eb e duhur t\u00eb aditiv\u00ebve t\u00eb sinterimit C + B4C; procesi i sinterimit t\u00eb karbhidit t\u00eb silikonit \u00ebsht\u00eb i thjesht\u00eb dhe i leht\u00eb p\u00ebr t'u kontrolluar. Krahasuar me bllokun, sinterimi i qeramik\u00ebs shkakton tkurrje volumetrike rreth 30\u201335%, duke mund\u00ebsuar arritjen e dend\u00ebsis\u00eb dhe vetive mekanike m\u00eb t\u00eb larta t\u00eb qeramik\u00ebs speciale t\u00eb karbhidit t\u00eb silikonit. Aktualisht, aditiv\u00ebt m\u00eb t\u00eb p\u00ebrdorur t\u00eb sinterimit jan\u00eb B4C + C, BN + C, BP (fosfid borri) + C, AI + C, AIN + C e k\u00ebshtu me radh\u00eb. Shtoni sasin\u00eb e duhur t\u00eb C + B4C n\u00eb procesin pa presion t\u00eb sinterimit t\u00eb SiC, procesi p\u00ebr k\u00ebt\u00eb lloj SiC t\u00eb sinteruar \u00ebsht\u00eb i thjesht\u00eb, i leht\u00eb p\u00ebr t'u kontrolluar, dend\u00ebsia e materialit \u00ebsht\u00eb m\u00eb e lart\u00eb, dend\u00ebsia maksimale \u00ebsht\u00eb 3.169\/cm3 (dend\u00ebsi relative 98.75%); vetit\u00eb mekanike jan\u00eb m\u00eb t\u00eb mira, forca maksimale kompresive \u00ebsht\u00eb 550MPa.
\n Materiali i pap\u00ebrpunuar i karbidi i silikonit preferohet t\u00eb jet\u00eb mikropud\u00ebr e vetme me vler\u00eb D50 prej 0,5\u20130,8 mikron\u00ebsh. Zakonisht jan\u00eb mikron\u00eb jeshil\u00eb karbidi silikoni t\u00eb trajtuar kimikisht me nj\u00eb sip\u00ebrfaqe specifike prej 20 m3\/g. P\u00ebrmbajtja e oksigjenit duhet t\u00eb jet\u00eb sa m\u00eb e ul\u00ebt; m\u00eb tej, sasia e B-s\u00eb s\u00eb shtuar duhet t\u00eb zgjidhet rreth 0.5% \u2013 1.5%, nd\u00ebrsa sasia e C-s\u00eb s\u00eb shtuar varet nga niveli i p\u00ebrmbajtjes s\u00eb oksigjenit n\u00eb pluhurin SiC. P\u00ebrb\u00ebrja kimike: SiC > 99%, F-C < 0.1, Si + SiO2 < 0.1, Fe2O3 < 0.08. Forma dhe madh\u00ebsia e grimcave: forma e grimc\u00ebs \u00ebsht\u00eb pothuajse sferike p\u00ebr t\u00eb arritur grumbullimin m\u00eb kompakt.
\n Shtimi i B4C dhe C i p\u00ebrket kategoris\u00eb s\u00eb sinterimit n\u00eb faz\u00eb t\u00eb ngurt\u00eb, i cili k\u00ebrkon temperatura m\u00eb t\u00eb larta sinterimi. Forca l\u00ebviz\u00ebse e sinterimit t\u00eb SiC \u00ebsht\u00eb: diferenca midis energjis\u00eb s\u00eb sip\u00ebrfaqes s\u00eb grimcave t\u00eb pluhurit (Eb) dhe sip\u00ebrfaqes s\u00eb luhatshme t\u00eb kokrrizave t\u00eb trupit polikristalor t\u00eb sinteruar (Es), gj\u00eb q\u00eb \u00e7on n\u00eb nj\u00eb ulje t\u00eb energjis\u00eb s\u00eb lir\u00eb t\u00eb sistemit. Dopimi me nj\u00eb sasi t\u00eb p\u00ebrshtatshme B4C gjat\u00eb sinterimit vendos B4C n\u00eb kufirin e grimcave t\u00eb SiC, duke formuar pjes\u00ebrisht nj\u00eb zgjidhje t\u00eb ngurt\u00eb me SiC, dhe k\u00ebshtu duke reduktuar kapacitetin e kufirit t\u00eb grimcave t\u00eb SiC. Dopimi me nj\u00eb sasi t\u00eb moderuar C t\u00eb lir\u00eb \u00ebsht\u00eb i dobish\u00ebm p\u00ebr sinterimin n\u00eb faz\u00eb t\u00eb ngurt\u00eb sepse sip\u00ebrfaqja e SiC zakonisht \u00ebsht\u00eb e oksiduar, duke rezultuar n\u00eb gjenerimin e nj\u00eb sasie t\u00eb vog\u00ebl SiO2, dhe shtimi i nj\u00eb sasie t\u00eb moderuar C ndihmon n\u00eb reduktimin e film\u00ebs SiO2 n\u00eb sip\u00ebrfaqen e SiC, duke rritur k\u00ebshtu energjin\u00eb e sip\u00ebrfaqes Eb.
\n Sistemi SiC kalon n\u00eb dekompozim dhe sublimim n\u00eb 1.013x105 Pa dhe n\u00eb nj\u00eb temperatur\u00eb m\u00eb t\u00eb lart\u00eb se 1880 \u00b0C. Sistemi SiC p\u00ebrmban faza gazi t\u00eb tilla si Si, Si2, Si3, C, C2, C3, C4, C5, SiC, Si2C, SiC2 e k\u00ebshtu me radh\u00eb, dhe ndryshimi i temperatur\u00ebs \u00ebsht\u00eb nxit\u00ebsi themelor i procesit t\u00eb sublimimit gjat\u00eb rritjes s\u00eb kristaleve SiC, dhe i gjith\u00eb procesi dominohet nga transporti i mas\u00ebs. K\u00ebto faza t\u00eb ndryshme gazi n\u00eb sistemin SiC bashkohen mbi kristal-n\u00ebn\u00ebn e SiC-s\u00eb p\u00ebrmes difuzionit, duke \u00e7uar n\u00eb rritjen e grimcave t\u00eb kristaleve t\u00eb SiC-s\u00eb. P\u00ebr mostrat e sistemit ndihm\u00ebs p\u00ebr sinterim C+B4C, temperatura e k\u00ebrkuar e sinterimit \u00ebsht\u00eb m\u00eb e lart\u00eb p\u00ebr shkak t\u00eb sinterimit kryesisht n\u00eb faz\u00eb t\u00eb ngurt\u00eb, dhe argoni kalon si atmosfer\u00eb mbrojt\u00ebse n\u00eb rreth 1300 \u00b0C, sepse argoni \u00ebsht\u00eb i favorsh\u00ebm p\u00ebr reduktimin e dekompozimit t\u00eb SiC n\u00eb temperatura t\u00eb larta mbi 1300 \u00b0C. Matja e cil\u00ebsis\u00eb s\u00eb trupit t\u00eb sinteruar t\u00eb SiC ka dy kushte t\u00eb nevojshme: porozitet t\u00eb ul\u00ebt, sa m\u00eb t\u00eb dendur; grimca sa m\u00eb t\u00eb vogla.<\/p>","protected":false},"excerpt":{"rendered":"
The sintering of silicon carbide ceramic containing C and B4C elements as sintering aids is solid-phase sintering, and the sintering process is mainly controlled by the diffusion mechanism, with an optimum sintering temperature of 2150\u00b0C. The sintering process is simple and easy to control. Add the appropriate content of C + B4C sintering additives […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0,"footnotes":""},"categories":[30],"tags":[],"class_list":["post-574","post","type-post","status-publish","format-standard","hentry","category-sic-knowledge"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/siliconcarbide.net\/sq\/wp-json\/wp\/v2\/posts\/574","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/siliconcarbide.net\/sq\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/siliconcarbide.net\/sq\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/siliconcarbide.net\/sq\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/siliconcarbide.net\/sq\/wp-json\/wp\/v2\/comments?post=574"}],"version-history":[{"count":3,"href":"https:\/\/siliconcarbide.net\/sq\/wp-json\/wp\/v2\/posts\/574\/revisions"}],"predecessor-version":[{"id":577,"href":"https:\/\/siliconcarbide.net\/sq\/wp-json\/wp\/v2\/posts\/574\/revisions\/577"}],"wp:attachment":[{"href":"https:\/\/siliconcarbide.net\/sq\/wp-json\/wp\/v2\/media?parent=574"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/siliconcarbide.net\/sq\/wp-json\/wp\/v2\/categories?post=574"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/siliconcarbide.net\/sq\/wp-json\/wp\/v2\/tags?post=574"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}