{"id":82,"date":"2024-05-30T07:55:29","date_gmt":"2024-05-29T23:55:29","guid":{"rendered":"https:\/\/aluminaceramics.net\/?p=82"},"modified":"2024-07-15T20:22:29","modified_gmt":"2024-07-15T12:22:29","slug":"alumina-formulu","status":"publish","type":"post","link":"https:\/\/aluminaceramics.net\/tr\/alumina-formula\/","title":{"rendered":"Al\u00fcmina Form\u00fcl\u00fc"},"content":{"rendered":"

Al\u00fcmina olarak da adland\u0131r\u0131lan al\u00fcminyum oksit (Al2O3), m\u00fckemmel kimyasal dirence ve orta d\u00fczeyde gerilme ve e\u011filme mukavemetine sahip bir elektrik yal\u0131tkan\u0131d\u0131r; ancak e\u011filme toklu\u011fu d\u00fc\u015f\u00fckt\u00fcr.<\/p>\n

Al\u00fcmina, bollu\u011fu, d\u00fc\u015f\u00fck maliyeti ve di\u011fer oksitlere g\u00f6re \u00fcst\u00fcn mekanik \u00f6zellikleri nedeniyle oksit seramikler s\u00f6z konusu oldu\u011funda ba\u015fvurulan malzemedir.<\/p>\n

Kimyasal Form\u00fcl<\/h2>\n

Al\u00fcminyum oksit (daha yayg\u0131n olarak al\u00fcmina veya alundum olarak adland\u0131r\u0131l\u0131r), Al2O3 form\u00fcl\u00fcne sahip, y\u00fcksek erime noktas\u0131na ve g\u00fc\u00e7l\u00fc sertli\u011fe, beyaz renge, suda \u00e7\u00f6z\u00fcnmezli\u011fe ve amfoterik \u00f6zelliklere - hem asidik hem de alkalin reaksiyona girme - sahip inorganik bir kimyasal bile\u015fiktir ve onu en pop\u00fcler end\u00fcstriyel seramiklerden biri yapar. Al\u00fcmina do\u011fal olarak korindon, yakut ve safir olarak ortaya \u00e7\u0131kmas\u0131n\u0131n yan\u0131 s\u0131ra boksitte ana al\u00fcminyum cevheri olarak bulunurken, \u00fcretim y\u00f6ntemleri aras\u0131nda bir al\u00fcminat \u00e7\u00f6zeltisinin kimyasal olarak dehidrasyonu veya bir al\u00fcminat \u00e7\u00f6zeltisinin kimyasal dehidrasyonu yer almaktad\u0131r.<\/p>\n

Al\u00fcmina, \u0131s\u0131 ve elektrik yal\u0131t\u0131m\u0131 \u00f6zelliklerinin yan\u0131 s\u0131ra \u00fcretim s\u00fcre\u00e7leri s\u0131ras\u0131nda kullan\u0131lan kimyasallar\u0131n neden oldu\u011fu korozyona kar\u015f\u0131 direnci nedeniyle f\u0131r\u0131nlar, ocaklar ve yakma f\u0131r\u0131nlar\u0131 gibi y\u00fcksek s\u0131cakl\u0131ktaki cihazlar\u0131n kaplanmas\u0131nda yayg\u0131n olarak kullan\u0131lmaktad\u0131r. Al\u00fcmina, m\u00fckemmel \u0131s\u0131 ve elektrik yal\u0131t\u0131m\u0131 \u00f6zelliklerinin yan\u0131 s\u0131ra korozyona kar\u015f\u0131 koruma sa\u011flar; bu da onu ideal malzeme se\u00e7imi haline getirir.<\/p>\n

Al\u00fcmina en sert m\u00fchendislik malzemelerinden biridir, sertlikte elmasa rakiptir ve a\u015f\u0131nma direnci a\u00e7\u0131s\u0131ndan silikon karb\u00fcrden sonra ikinci s\u0131radad\u0131r. Ayr\u0131ca, al\u00fcmina m\u00fckemmel bir yal\u0131tkan g\u00f6revi g\u00f6r\u00fcr ve \u0131s\u0131 transferinin verimli ve \u00f6ng\u00f6r\u00fclebilir bir \u015fekilde ger\u00e7ekle\u015fmesini sa\u011flayan d\u00fc\u015f\u00fck bir genle\u015fme katsay\u0131s\u0131na sahiptir.<\/p>\n

Al\u00fcminan\u0131n en kararl\u0131 polimorfu olan korundum, en kararl\u0131 formlar\u0131ndan biridir. Oksijen iyonlar\u0131n\u0131n c eksenine paralel katmanlar\u0131 i\u015fgal etti\u011fi, al\u00fcminyumun ise oktahedral aral\u0131klar\u0131n \u00fc\u00e7te ikisini doldurdu\u011fu trigonal Bravais kafes yap\u0131s\u0131na sahiptir. Korundumun oksijen iyonlar\u0131: al\u00fcminyum iyonlar\u0131 oran\u0131 1:2:1'dir.<\/p>\n

Kristalin al\u00fcmina, d\u00fc\u015f\u00fck \u00f6zg\u00fcl a\u011f\u0131rl\u0131\u011fa ve sertli\u011fe sahip ekonomik bir malzemedir ve tipik olarak 0,3 ila 0,8 mm aras\u0131nda partik\u00fcl boyutlar\u0131na sahip toz halinde bulunur. Kristalin al\u00fcmina tozunun iki formu vard\u0131r; A tipi alt\u0131gen kristaller i\u00e7erir ve 4.0 yo\u011funlu\u011fa sahiptir, B tipi ise 3.0 yo\u011funlukta k\u00fcbik kristallere sahiptir; her ikisi de A tipi daha h\u0131zl\u0131 kesme ile iyi a\u015f\u0131nma direnci sergiler.<\/p>\n

94% safl\u0131kta al\u00fcmina \u00fcretilebilir, ancak \u00e7o\u011fu ticari uygulama tipik olarak 85%-100% aras\u0131nda safl\u0131klar gerektirir. Daha d\u00fc\u015f\u00fck safl\u0131ktaki kaliteler genellikle refrakter uygulamalarda kullan\u0131l\u0131rken, daha y\u00fcksek safl\u0131ktaki kaliteler zirkonya sertle\u015ftirilmi\u015f al\u00fcmina (ZTA) seramiklerinde veya sert ve yo\u011fun ZTA kaliteleri gibi monolitik seramiklerde bulunabilir.<\/p>\n

Fiziksel \u00d6zellikler<\/h2>\n

Genellikle al\u00fcmina olarak adland\u0131r\u0131lan al\u00fcminyum oksit (Al2O3), metaller ve ala\u015f\u0131mlar gibi y\u00fck alt\u0131nda akmayan iyonik-kovalent bir kat\u0131d\u0131r. Al\u00fcminan\u0131n d\u00fc\u015f\u00fck elektrik iletkenli\u011fi ve termal kararl\u0131l\u0131\u011f\u0131 onu m\u00fckemmel bir yal\u0131tkan, kimyasal sald\u0131r\u0131lara kar\u015f\u0131 m\u00fckemmel diren\u00e7 ve a\u015f\u0131r\u0131 sertlik (Mohs \u00f6l\u00e7e\u011finde 9) haline getirir. Y\u00fcksek erime noktas\u0131 nedeniyle d\u00f6k\u00fcm\u00fc m\u00fcmk\u00fcn de\u011fildir, ancak g\u00fcc\u00fc, dayan\u0131kl\u0131l\u0131\u011f\u0131 ve korozyon direnci onu f\u0131r\u0131nlar ve ocaklar gibi zorlu i\u015fleme ortamlar\u0131nda kullan\u0131m i\u00e7in uygun hale getirir.<\/p>\n

Al\u00fcminadan olu\u015fan seramik astarlar, metal nozullar\u0131 ve m\u0131zraklar\u0131 korumak i\u00e7in y\u00fcksek f\u0131r\u0131n astarlar\u0131, \u00e7elik f\u0131r\u0131nlar\u0131 ve d\u00f6ner f\u0131r\u0131nlar i\u00e7in refrakter astarlar ve ayr\u0131ca d\u00f6k\u00fclebilir refrakter tu\u011fla d\u00f6k\u00fcm kum d\u00f6k\u00fcm i\u015flemleri olarak yayg\u0131n \u015fekilde kullan\u0131lmaktad\u0131r. Al\u00fcmina, b\u00fck\u00fclme veya \u00e7atlama olmaks\u0131z\u0131n \u00e7ok y\u00fcksek s\u0131cakl\u0131klara dayanmas\u0131n\u0131 sa\u011flayan d\u00fc\u015f\u00fck bir genle\u015fme katsay\u0131s\u0131na sahiptir; ayr\u0131ca, bak\u0131r tel uygulamalar\u0131 a\u015f\u0131nd\u0131r\u0131c\u0131 ortamlar gibi zorlu elektrik uygulamalar\u0131nda bir elektrik teli yal\u0131t\u0131m uygulamas\u0131 yal\u0131tkan\u0131 olarak ba\u015far\u0131s\u0131n\u0131n kan\u0131tlad\u0131\u011f\u0131 gibi asit sald\u0131r\u0131s\u0131na kar\u015f\u0131 diren\u00e7lidir.<\/p>\n

Al\u00fcminan\u0131n y\u00fcksek erime noktas\u0131 onu cam \u00fcretimi i\u00e7in ideal bir refrakter malzeme haline getirmektedir; bir\u00e7ok pencere ve kap cam\u0131nda sadece eser miktarda Al2O3 bulunmaktad\u0131r. Bu camlar s\u0131r olarak kullan\u0131lsayd\u0131, bile\u015fimlerinde yeterli refrakter element bulunmamas\u0131 nedeniyle akar ve \u00e7atlarlard\u0131.<\/p>\n

Bununla birlikte, bir cam re\u00e7etesine az miktarda al\u00fcmina eklenmesi, gerilme mukavemetini, y\u00fczey gerilimini, parlakl\u0131\u011f\u0131, \u00e7al\u0131\u015fma aral\u0131\u011f\u0131 uzunlu\u011funu, devitrifikasyon direncini ve toklu\u011fu art\u0131r\u0131rken daha d\u00fc\u015f\u00fck bir s\u0131cakl\u0131kta erimesini sa\u011flar. Ayr\u0131ca, sadece bir tutam eklemek e\u011filme ve gerilme mukavemetlerini art\u0131r\u0131r ve k\u0131r\u0131lgan k\u0131r\u0131lma davran\u0131\u015f\u0131n\u0131 \u00f6nemli \u00f6l\u00e7\u00fcde azalt\u0131r.<\/p>\n

Al\u00fcminan\u0131n refrakter \u00f6zellikleri, onu di\u015f implantlar\u0131 ve di\u011fer biyomedikal uygulamalar i\u00e7in kullan\u0131lan t\u0131bbi al\u00fcmina olarak kullan\u0131m i\u00e7in m\u00fckemmel bir aday haline getirmektedir. Medikal al\u00fcmina, geni\u015f safl\u0131k aral\u0131klar\u0131nda hassas a\u011fa yak\u0131n \u015fekiller \u00fcreten \u00e7e\u015fitli konsolidasyon ve sinterleme teknikleri kullan\u0131larak \u00fcretilir. Orta d\u00fczeydeki gerilme\/e\u011filme mukavemeti, implant uygulamalar\u0131 i\u00e7in polikristalin al\u00fcmina implantlar\u0131n gerektirdi\u011finin alt\u0131nda kalsa da, \u00fcst\u00fcn mekanik performans\u0131 bu malzemeyi t\u0131bbi uygulamalar i\u00e7in dikkate de\u011fer k\u0131lmaktad\u0131r.<\/p>\n

Termal \u00d6zellikler<\/h2>\n

Al\u00fcmina, g\u00fc\u00e7l\u00fc atomlar aras\u0131 ba\u011f\u0131 sayesinde di\u011fer metallerden veya ala\u015f\u0131mlardan ayr\u0131l\u0131r ve y\u00fcksek mukavemet ve sertlik, hem d\u00fc\u015f\u00fck hem de y\u00fcksek s\u0131cakl\u0131klarda m\u00fckemmel dielektrik \u00f6zellikler, hem oda hem de y\u00fcksek s\u0131cakl\u0131klarda kimyasal sald\u0131r\u0131lara ve korozyona kar\u015f\u0131 m\u00fckemmel diren\u00e7, y\u00fcksek s\u0131cakl\u0131klarda \u00fcst\u00fcn termal \u00f6zellikler ve verimli bir \u0131s\u0131 emici \u00e7\u00f6z\u00fcm sa\u011flama dahil olmak \u00fczere ba\u015fka yerlerde g\u00f6r\u00fclmeyen benzersiz \u00f6zellikler verir.<\/p>\n

Al\u00fcmina gran\u00fcl, toz ve bulama\u00e7lar dahil olmak \u00fczere \u00e7e\u015fitli formlarda gelir ve \u00e7e\u015fitli \u015fekillerde olu\u015fturulabilir. Orta derecede gerilme mukavemeti ve e\u011filme b\u00fck\u00fclme mukavemetine sahip olan Al\u00fcmina, termal iletkenli\u011fi ve erime noktas\u0131n\u0131n nispeten d\u00fc\u015f\u00fck olmas\u0131 nedeniyle bir\u00e7ok polikristal seramik malzemeden farkl\u0131d\u0131r - bu da b\u00fcy\u00fck par\u00e7alar\u0131n d\u00f6k\u00fcm\u00fcn\u00fcn imkans\u0131z oldu\u011fu anlam\u0131na gelir.<\/p>\n

Alfa faz al\u00fcmina (Al2O3), al\u00fcminan\u0131n yap\u0131sal uygulamalar\u0131 i\u00e7in en s\u0131k kullan\u0131lan malzemedir. Bu polikristalin form, t\u00fcm oktahedral aral\u0131klar\u0131n \u00fc\u00e7te ikisini dolduran alt\u0131gen olarak yak\u0131n paketlenmi\u015f oksijen iyonlar\u0131na sahiptir. Al\u00fcmina ayr\u0131ca k\u00fcbik g ve e fazlar\u0131nda, monoklinik k faz\u0131nda ve ortorombik d faz\u0131nda metastabilite g\u00f6sterir ve bunlar\u0131n hepsi y\u00fcksek s\u0131cakl\u0131klarda kararl\u0131 hekzagonal alfa faz\u0131na geri d\u00f6ner.<\/p>\n

Saf al\u00fcminan\u0131n bir\u00e7ok end\u00fcstriyel kullan\u0131m\u0131 vard\u0131r ve tipik olarak NaAlO form\u00fcll\u00fc sodyum al\u00fcminat formunda tedarik edilir. Bu malzeme, sodyum al\u00fcminat \u00fcretmek i\u00e7in boksitin y\u00fcksek s\u0131cakl\u0131klarda kavrulmas\u0131yla \u00fcretilir ve daha sonra ileri i\u015flemler i\u00e7in bir bulama\u00e7 \u00fcretmek \u00fczere suyla kar\u0131\u015ft\u0131r\u0131lmadan \u00f6nce ince toz haline getirilir.<\/p>\n

Modern al\u00fcmina \u00fcr\u00fcnleri tipik olarak 85%-100% safl\u0131k seviyeleri aras\u0131ndad\u0131r, bu da onu bujiler ve mikro\u00e7ip substratlar\u0131n\u0131n yan\u0131 s\u0131ra kal\u0131n film kaplama gibi y\u00fcksek performansl\u0131 seramik uygulamalar\u0131 i\u00e7in uygun hale getirir.<\/p>\n

Saf al\u00fcmina, porselen elektrik yal\u0131t\u0131m\u0131ndan oda s\u0131cakl\u0131klar\u0131nda en az iki, y\u00fcksek s\u0131cakl\u0131klarda ise d\u00f6rt kat daha iyi performans g\u00f6sterir ve bozulmaya neden olan alkali sald\u0131r\u0131lar\u0131na kar\u015f\u0131 \u00f6nemli \u00f6l\u00e7\u00fcde daha az savunmas\u0131zd\u0131r.<\/p>\n

Mekanik \u00d6zellikler<\/h2>\n

Al\u00fcminan\u0131n mekanik \u00f6zellikleri aras\u0131nda mukavemeti veya gerilme-stres tolerans\u0131 yer al\u0131r. Bu \u00f6zellik, al\u00fcmina seramikleri \u015foklara kar\u015f\u0131 olduk\u00e7a diren\u00e7li hale getirir, yo\u011fun bas\u0131n\u00e7 alt\u0131nda bile \u015fekillerini ve boyutlar\u0131n\u0131 korur. Ayr\u0131ca al\u00fcmina, a\u011f\u0131r y\u00fckleri hasar g\u00f6rmeden desteklemek i\u00e7in y\u00fcksek bas\u0131n\u00e7 dayan\u0131m\u0131na sahipken, \u00e7ekme ve e\u011filme dayan\u0131mlar\u0131 yap\u0131sal bile\u015fenlerin ve par\u00e7alar\u0131n sa\u011flam ve i\u015flevsel kalmas\u0131n\u0131 sa\u011flar.<\/p>\n

Al\u00fcmina, dayan\u0131kl\u0131l\u0131\u011f\u0131 ve kimyasal sald\u0131r\u0131lara kar\u015f\u0131 direnci gibi m\u00fckemmel mekanik \u00f6zelliklere sahiptir, bu da onu enerji santralleri ve fabrikalar dahil olmak \u00fczere end\u00fcstriyel ve ticari uygulamalar i\u00e7in uygun hale getirir. G\u00fcn\u00fcm\u00fczde mevcut en dayan\u0131kl\u0131 m\u00fchendislik seramiklerinden biri olan al\u00fcmina, a\u015f\u0131r\u0131 s\u0131cakl\u0131klara ve a\u015f\u0131nma ve y\u0131pranmaya dayanabilir, bu da onu elektrik izolat\u00f6rleri, gaz lazer t\u00fcpleri, conta halkalar\u0131 ve laboratuvar ekipmanlar\u0131 gibi \u00fcr\u00fcnlerin \u00fcretimi i\u00e7in m\u00fckemmel bir malzeme se\u00e7imi haline getirir.<\/p>\n

Al\u00fcminan\u0131n sald\u0131r\u0131lara kar\u015f\u0131 direnci, onu ayn\u0131 zamanda koruyucu z\u0131rh \u00fcretiminde aranan bir malzeme haline getirerek askeri ara\u00e7 ve personel \u00fcreticileri aras\u0131nda tercih edilen se\u00e7eneklerden biri yapmaktad\u0131r. Al\u00fcminan\u0131n sertli\u011fi ve biyoinertli\u011fi burada \u00f6zellikle yararl\u0131d\u0131r; bu da onu kal\u00e7a protezi yataklar\u0131, biyonik implantlar, doku takviyesi, doku iskelesi uygulamalar\u0131 ve kal\u00e7a protezi yataklar\u0131 gibi t\u0131bbi kullan\u0131m uygulamalar\u0131 olu\u015fturmak i\u00e7in uygun hale getirir. Ayr\u0131ca, dayan\u0131kl\u0131l\u0131\u011f\u0131 da al\u00fcminay\u0131 balistik z\u0131rh \u00fcretiminde m\u00fckemmel bir se\u00e7im haline getirmektedir.<\/p>\n

Al\u00fcmina seramikler d\u00fc\u015f\u00fck akut ve kronik toksisiteye sahiptir ve k\u0131sa maruz kalma s\u00fcrelerinde sadece k\u00fc\u00e7\u00fck cilt tahri\u015fine yol a\u00e7arak t\u0131bbi ekipman ve sa\u011fl\u0131k uygulamalar\u0131nda kullan\u0131m i\u00e7in ideal bir malzeme haline gelir. \u00c7e\u015fitli kimyasallarla reaktif olmamalar\u0131, al\u00fcmina seramikleri tungsten karb\u00fcr gibi cerrahi alet ikameleri olarak giderek daha yayg\u0131n hale getirmektedir; ancak t\u0131bbi al\u00fcminada optimum tokluk gereksinimleri i\u00e7in \u00f6ncelikle sinterleme i\u015flemi s\u0131ras\u0131nda s\u0131k\u0131 bir d\u00fczenlemeden ge\u00e7mesi gerekir.<\/p>\n

\"Al\u00fcmina<\/p>","protected":false},"excerpt":{"rendered":"

Aluminum oxide (Al2O3), also referred to as alumina, is an electrical insulator with excellent chemical resistance and moderate tensile 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":"default","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":"default","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","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":[6],"tags":[],"class_list":["post-82","post","type-post","status-publish","format-standard","hentry","category-alumina-knowledge"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/aluminaceramics.net\/tr\/wp-json\/wp\/v2\/posts\/82","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/aluminaceramics.net\/tr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/aluminaceramics.net\/tr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/aluminaceramics.net\/tr\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/aluminaceramics.net\/tr\/wp-json\/wp\/v2\/comments?post=82"}],"version-history":[{"count":3,"href":"https:\/\/aluminaceramics.net\/tr\/wp-json\/wp\/v2\/posts\/82\/revisions"}],"predecessor-version":[{"id":206,"href":"https:\/\/aluminaceramics.net\/tr\/wp-json\/wp\/v2\/posts\/82\/revisions\/206"}],"wp:attachment":[{"href":"https:\/\/aluminaceramics.net\/tr\/wp-json\/wp\/v2\/media?parent=82"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/aluminaceramics.net\/tr\/wp-json\/wp\/v2\/categories?post=82"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/aluminaceramics.net\/tr\/wp-json\/wp\/v2\/tags?post=82"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}