Bas\u0131n\u00e7s\u0131z sinterlenmi\u015f silisyum karb\u00fcr, en umut verici sinterlenmi\u015f silisyum karb\u00fcr olarak kabul edilir ve bas\u0131n\u00e7s\u0131z sinterleme i\u015flemi ile karma\u015f\u0131k \u015fekiller ve b\u00fcy\u00fck boyutlarda silisyum karb\u00fcr seramikler haz\u0131rlanabilir. Sinterleme mekanizmas\u0131na ba\u011fl\u0131 olarak, bu t\u00fcr sinterlenmi\u015f silisyum karb\u00fcr ayr\u0131ca kat\u0131 faz sinterleme ve s\u0131v\u0131 faz sinterleme olarak ikiye ayr\u0131labilir. Eser miktarda SiO i\u00e7eren \u03b2-SiC, B ve C eklenerek atmosferik bas\u0131n\u00e7ta sinterlenebilir. Bu y\u00f6ntem, silisyum karb\u00fcr\u00fcn sinterleme kineti\u011fini \u00f6nemli \u00f6l\u00e7\u00fcde geli\u015ftirir. Uygun miktarda B ile katk\u0131lanan B, sinterleme s\u0131ras\u0131nda SiC tane s\u0131n\u0131rlar\u0131nda bulunur ve k\u0131smen SiC ile kat\u0131 bir \u00e7\u00f6zelti olu\u015fturur, b\u00f6ylece SiC'nin tane s\u0131n\u0131r\u0131 enerjisini azalt\u0131r. Orta miktarda serbest C katk\u0131s\u0131, kat\u0131 faz sinterleme i\u00e7in faydal\u0131d\u0131r \u00e7\u00fcnk\u00fc SiC y\u00fczeyi genellikle az miktarda SiO olu\u015fumuyla oksitlenir ve orta miktarda C ilavesi, SiC y\u00fczeyindeki SiO filminin azalt\u0131lmas\u0131na ve \u00e7\u0131kar\u0131lmas\u0131na yard\u0131mc\u0131 olur, b\u00f6ylece y\u00fczey enerjisini artt\u0131r\u0131r. Bununla birlikte, s\u0131v\u0131 faz sinterlemenin olumsuz bir etkisi olacakt\u0131r, \u00e7\u00fcnk\u00fc C gaz \u00fcretmek i\u00e7in oksit katk\u0131 maddeleri ile reaksiyona girecek, seramik sinterleme g\u00f6vdesinde \u00e7ok say\u0131da a\u00e7\u0131kl\u0131k olu\u015facak ve yo\u011funla\u015ft\u0131rma s\u00fcrecini etkileyecektir. Hammaddenin safl\u0131\u011f\u0131, inceli\u011fi ve faz bile\u015fimi silisyum karb\u00fcr\u00fcn sinterleme s\u00fcrecinde \u00e7ok \u00f6nemlidir.S.Proehazka, ultra ince \u03b2-SiC tozlar\u0131na (2%'den az oksijen i\u00e7eren) uygun miktarlarda B ve C'yi ayn\u0131 anda ekleyerek atmosferik bas\u0131n\u00e7 alt\u0131nda 2020 \u00b0 C'de 98%'den daha y\u00fcksek bir yo\u011funlu\u011fa sahip sinterlenmi\u015f silisyum karb\u00fcr\u00fc sinterledi. Bununla birlikte, SiC-B-C sistemi, y\u00fcksek sinterleme s\u0131cakl\u0131\u011f\u0131 ve d\u00fc\u015f\u00fck k\u0131r\u0131lma toklu\u011fu gerektiren kat\u0131 faz sinterleme kategorisine aittir, k\u0131r\u0131lma modu tipik bir kristaller aras\u0131 k\u0131r\u0131lma, iri taneler ve zay\u0131f homojenliktir. SiC \u00fczerine yap\u0131lan yabanc\u0131 ara\u015ft\u0131rmalar\u0131n odak noktas\u0131, SiC yo\u011funla\u015ft\u0131rmas\u0131n\u0131 sa\u011flamak i\u00e7in daha d\u00fc\u015f\u00fck bir s\u0131cakl\u0131kta s\u0131v\u0131 faz sinterlemesinde, yani belirli say\u0131da sinterleme katk\u0131 maddesinde yo\u011funla\u015fm\u0131\u015ft\u0131r. SiC'nin s\u0131v\u0131 faz sinterlemesi sadece kat\u0131 faz sinterlemeye g\u00f6re sinterleme s\u0131cakl\u0131\u011f\u0131n\u0131 d\u00fc\u015f\u00fcrmekle kalmaz, ayn\u0131 zamanda mikro yap\u0131y\u0131 da iyile\u015ftirir ve b\u00f6ylece sinterlenmi\u015f g\u00f6vdenin \u00f6zellikleri kat\u0131 faz sinterlenmi\u015f g\u00f6vdenin \u00f6zelliklerine k\u0131yasla iyile\u015ftirilir.
\nM. Omori ve arkada\u015flar\u0131, SiC'yi yo\u011fun bir \u015fekilde sinterlemek i\u00e7in AlO veya bor\u00fcrlerle kar\u0131\u015ft\u0131r\u0131lm\u0131\u015f nadir toprak oksitleri kullanm\u0131\u015ft\u0131r. Suzuki ise SiC'yi yakla\u015f\u0131k 2000\u00b0C'de katk\u0131 maddesi olarak sadece AlO ile sinterlemi\u015ftir. A. Mulla ve arkada\u015flar\u0131 0,5 \u03bcm \u03b2-SiC'yi (partik\u00fcllerin y\u00fczeyinde az miktarda SiO ile) katk\u0131 maddesi olarak AlO ve YO ile 1850-1950\u00b0C'de sinterlemi\u015f ve teorik yo\u011funlu\u011fun 95%'sinden daha y\u00fcksek bir SiC seramik ba\u011f\u0131l yo\u011funlu\u011fu elde etmi\u015flerdir ve taneler ortalama 1,5 \u03bcm boyutunda ince yap\u0131dad\u0131r.
\nSilisyum karb\u00fcr seramiklerin mikro yap\u0131s\u0131n\u0131n iri tanelere ve iyi k\u0131r\u0131lma toklu\u011funa sahip \u00e7ubuk benzeri bir yap\u0131ya sahip oldu\u011fu bulunmu\u015ftur. \u00c7ubuk benzeri taneler, silisyum karb\u00fcr seramiklerin mukavemetini azalt\u0131rken k\u0131r\u0131lma toklu\u011funu art\u0131r\u0131r. Sinterleme s\u0131cakl\u0131\u011f\u0131n\u0131 d\u00fc\u015f\u00fcr\u00fcrken daha iyi mukavemet ve tokluk elde etmek i\u00e7in, cam faz\u0131 bile\u015fimini farkl\u0131 katk\u0131 maddeleri ile ayarlayarak bu sinterlenmi\u015f silisyum karb\u00fcr\u00fcn \u00f6zelliklerini iyile\u015ftirmek i\u00e7in bir\u00e7ok giri\u015fimde bulunulmu\u015ftur. Sinterleme i\u015flemi s\u0131ras\u0131nda, tane s\u0131n\u0131r\u0131na s\u0131v\u0131 faz\u0131n girmesi ve benzersiz aray\u00fczey yap\u0131s\u0131, aray\u00fczey yap\u0131s\u0131n\u0131n zay\u0131flamas\u0131na ve malzemenin k\u0131r\u0131lmas\u0131n\u0131n tam bir kristal boyunca k\u0131r\u0131lma moduna d\u00f6n\u00fc\u015fmesine neden olmu\u015f, bu da malzemenin mukavemetinde ve toklu\u011funda \u00f6nemli bir art\u0131\u015fa neden olmu\u015ftur. Bununla birlikte, AlO katk\u0131s\u0131 kullan\u0131m\u0131n\u0131n d\u00fc\u015f\u00fck erime noktas\u0131na ve y\u00fcksek u\u00e7uculu\u011fa sahip cams\u0131 bir faz olu\u015fturdu\u011fu, bu faz\u0131n daha y\u00fcksek s\u0131cakl\u0131klarda g\u00fc\u00e7l\u00fc buharla\u015fmaya u\u011frayaca\u011f\u0131, malzemenin a\u011f\u0131rl\u0131k kayb\u0131na neden olaca\u011f\u0131 ve malzemenin yo\u011funla\u015fmas\u0131n\u0131 olumsuz etkileyece\u011fi g\u00f6z \u00f6n\u00fcnde bulundurularak, katk\u0131daki AlO k\u00fctle oran\u0131 uygun \u015fekilde art\u0131r\u0131lmal\u0131d\u0131r.<\/p>","protected":false},"excerpt":{"rendered":"
Pressureless sintered silicon carbide is considered to be the most promising sintered silicon carbide, and complex shapes and large sizes of silicon carbide ceramics can be prepared by the pressureless sintering process. Depending on the sintering mechanism, this kind of sintered silicon carbide can be further divided into solid-phase sintering and liquid-phase sintering. \u03b2-SiC containing […]<\/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-578","post","type-post","status-publish","format-standard","hentry","category-sic-knowledge"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/siliconcarbide.net\/tr\/wp-json\/wp\/v2\/posts\/578","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/siliconcarbide.net\/tr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/siliconcarbide.net\/tr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/siliconcarbide.net\/tr\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/siliconcarbide.net\/tr\/wp-json\/wp\/v2\/comments?post=578"}],"version-history":[{"count":1,"href":"https:\/\/siliconcarbide.net\/tr\/wp-json\/wp\/v2\/posts\/578\/revisions"}],"predecessor-version":[{"id":579,"href":"https:\/\/siliconcarbide.net\/tr\/wp-json\/wp\/v2\/posts\/578\/revisions\/579"}],"wp:attachment":[{"href":"https:\/\/siliconcarbide.net\/tr\/wp-json\/wp\/v2\/media?parent=578"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/siliconcarbide.net\/tr\/wp-json\/wp\/v2\/categories?post=578"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/siliconcarbide.net\/tr\/wp-json\/wp\/v2\/tags?post=578"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}