Al\u00fcminyum ala\u015f\u0131mlar\u0131n\u0131n eritilmesinin \u00f6zellikleri<\/p>\n
\u00c7o\u011fu al\u00fcminyum ala\u015f\u0131m\u0131n\u0131n eritilmesi zor de\u011fildir. Magnezyum, \u00e7inko ve bazen bak\u0131r hari\u00e7 olmak \u00fczere ala\u015f\u0131m bile\u015fenleri, ligat\u00fcrler \u015feklinde eklenir.
\nKural olarak, pota f\u0131r\u0131nlar\u0131nda k\u00fc\u00e7\u00fck miktarlarda d\u00f6k\u00fcm ala\u015f\u0131mlar\u0131n\u0131n eritilmesinde koruyucu ak\u0131 kullan\u0131lmaz. Zorunlu i\u015flem, metalik olmayan kal\u0131nt\u0131lar\u0131n ve \u00e7\u00f6z\u00fcnm\u00fc\u015f hidrojenin ar\u0131nd\u0131r\u0131lmas\u0131d\u0131r. Eritilmesi en zor olanlar, al\u00fcminyum-magnezyum ve \u00e7ok bile\u015fenli \u0131s\u0131ya dayan\u0131kl\u0131 ala\u015f\u0131mlard\u0131r.<\/p>\n
D\u00f6vme ala\u015f\u0131mlar\u0131 eritilirken, f\u0131r\u0131n\u0131n c\u00fcruftan ar\u0131nd\u0131r\u0131lmas\u0131na ve \u00f6nceki eritme kal\u0131nt\u0131lar\u0131n\u0131n toplanmas\u0131na \u00f6zel \u00f6nem verilir.
\nFarkl\u0131 bir ala\u015f\u0131m kalitesine ge\u00e7ilirken, ge\u00e7i\u015f eritmelerine ek olarak, f\u0131r\u0131n ve kar\u0131\u015ft\u0131r\u0131c\u0131lar da eski ala\u015f\u0131m kal\u0131nt\u0131lar\u0131n\u0131 temizlemek amac\u0131yla y\u0131kan\u0131r.
\nY\u0131kama i\u00e7in kullan\u0131lacak metal miktar\u0131, f\u0131r\u0131n kapasitesinin en az d\u00f6rtte biri kadar olmal\u0131d\u0131r.
\nY\u0131kama s\u0131ras\u0131nda metalin s\u0131cakl\u0131\u011f\u0131, y\u0131kamadan \u00f6nce ala\u015f\u0131m\u0131n d\u00f6k\u00fcm s\u0131cakl\u0131\u011f\u0131n\u0131n 40-50 \u00b0C \u00fczerinde tutulur.
\nTemizleme i\u015flemini h\u0131zland\u0131rmak i\u00e7in, f\u0131r\u0131n i\u00e7indeki metal 8-10 dakika boyunca yo\u011fun bir \u015fekilde kar\u0131\u015ft\u0131r\u0131l\u0131r.<\/p>\n
Y\u0131kama i\u015flemi i\u00e7in al\u00fcminyum veya yeniden eritme y\u00f6ntemi kullan\u0131l\u0131r. F\u0131r\u0131ndan \u00e7\u0131kan metalin tamamen erimi\u015f oldu\u011fu durumlarda, sadece ak\u0131 maddeleriyle y\u0131kama i\u015flemiyle yetinilebilir. Erime ala\u015f\u0131mlar\u0131 suya dald\u0131r\u0131l\u0131r
\nHammadde y\u00fcklemesi \u015fu s\u0131rayla ger\u00e7ekle\u015ftirilir: al\u00fcminyum d\u00f6k\u00fcnt\u00fc, hacimli at\u0131k, yeniden eritme malzemesi, ligat\u00fcrler (saf metaller).
\n730 \u00b0C\u2019yi a\u015fmayan bir s\u0131cakl\u0131kta, kuru tala\u015f ve k\u00fc\u00e7\u00fck boyutlu hurdalar\u0131n s\u0131v\u0131 metale y\u00fcklenmesine izin verilir.
\nBak\u0131r, 740\u2013750 \u00b0\u0421 s\u0131cakl\u0131kta, silikon ise 700\u2013740 \u00b0\u0421 s\u0131cakl\u0131kta bir \u00e7an kullan\u0131larak eriyik i\u00e7ine eklenir.
\n\u00c7inko, magnezyumdan \u00f6nce eklenir; magnezyum ise genellikle metalin bo\u015falt\u0131lmas\u0131ndan \u00f6nce eklenir. D\u00f6k\u00fcm ala\u015f\u0131mlar\u0131 i\u00e7in izin verilen maksimum a\u015f\u0131r\u0131 \u0131s\u0131nma s\u0131cakl\u0131\u011f\u0131 800-830 \u00b0C, d\u00f6vme ala\u015f\u0131mlar\u0131 i\u00e7in ise 750-760 \u00b0C\u2019dir.
\nAl\u00fcminyum, havada eridi\u011finde oksitlenir. Ba\u015fl\u0131ca oksitleyici maddeler oksijen ve su buhar\u0131d\u0131r. Bu gazlar\u0131n s\u0131cakl\u0131\u011f\u0131 ve bas\u0131nc\u0131na ve etkile\u015fimin kinetik ko\u015fullar\u0131na ba\u011fl\u0131 olarak, al\u00fcminyumun oksitlenmesi sonucunda al\u00fcminyum oksit (Al\u2082O\u2083) ile Al\u2082O ve AlO olu\u015fur.
\nOlu\u015fma olas\u0131l\u0131\u011f\u0131, s\u0131cakl\u0131\u011f\u0131n artmas\u0131 ve sistemdeki oksijen k\u0131smi bas\u0131nc\u0131n\u0131n azalmas\u0131yla birlikte artar.
\nNormal erime ko\u015fullar\u0131nda, termodinamik a\u00e7\u0131dan kararl\u0131 faz, al\u00fcminyumda \u00e7\u00f6z\u00fcnmeyen ve onunla eriyebilir bile\u015fikler olu\u015fturmayan \u03b3-Al\u2082O\u2083 kat\u0131 al\u00fcminad\u0131r. 1200 \u00b0C\u2019ye \u0131s\u0131t\u0131ld\u0131\u011f\u0131nda, \u03b3-Al\u2082O\u2083, \u03b1-Al\u2082O\u2083\u2019e yeniden kristalle\u015fir. Oksidasyon ilerledik\u00e7e, s\u0131cakl\u0131k ve maruz kalma s\u00fcresine ba\u011fl\u0131 olarak kat\u0131 ve s\u0131v\u0131 al\u00fcminyumun y\u00fczeyinde 0,1\u201310 \u00b5m kal\u0131nl\u0131\u011f\u0131nda yo\u011fun ve dayan\u0131kl\u0131 bir oksit tabakas\u0131 olu\u015fur. Bu kal\u0131nl\u0131\u011fa ula\u015f\u0131ld\u0131\u011f\u0131nda, oksijenin tabaka i\u00e7inden dif\u00fczyonu keskin bir \u015fekilde yava\u015flad\u0131\u011f\u0131ndan oksidasyon pratik olarak durur.<\/p>\n
S\u0131v\u0131 al\u00fcminyum ala\u015f\u0131mlar\u0131n\u0131n oksidasyon s\u00fcreci olduk\u00e7a karma\u015f\u0131kt\u0131r ve bu konuda yeterince ara\u015ft\u0131rma yap\u0131lmam\u0131\u015ft\u0131r. Mevcut literat\u00fcr verileri, ala\u015f\u0131m bile\u015fenlerinin oksidasyon h\u0131z\u0131n\u0131n oksijen bas\u0131nc\u0131, oksitlerinin ayr\u0131\u015fma bas\u0131nc\u0131, ala\u015f\u0131mdaki bile\u015fenlerin konsantrasyonu, atomlar\u0131n oksijen atomlar\u0131na do\u011fru dif\u00fczyon h\u0131z\u0131, oksitlerin kendi aralar\u0131ndaki etkile\u015fimi vb. fakt\u00f6rlerin bir fonksiyonu oldu\u011funu g\u00f6stermektedir. Oksidasyon kineti\u011fi, oksit filmlerinin s\u00fcreklili\u011fi, yo\u011funlu\u011fu ve mukavemeti taraf\u0131ndan belirlenir. Ayn\u0131 konsantrasyonda, oksit olu\u015fumu izobarik-izotermal potansiyeldeki en b\u00fcy\u00fck d\u00fc\u015f\u00fc\u015fle ili\u015fkili olan en aktif elementler oksitlenir.<\/p>\n
\u00c7o\u011fu ala\u015f\u0131m elementi (bak\u0131r, silikon, manganez), VMem0 \/ mVMe \u2265 1 oran\u0131na sahip olduklar\u0131 i\u00e7in al\u00fcminyumun oksidasyonunu ve oksit tabakas\u0131n\u0131n koruyucu \u00f6zelliklerini \u00f6nemli \u00f6l\u00e7\u00fcde etkilemez. Bu elementlerin d\u00fc\u015f\u00fck konsantrasyonlarda bulundu\u011fu ikili al\u00fcminyum ala\u015f\u0131mlar \u00fczerindeki oksit tabakas\u0131, saf \u03b3-Al2O3\u2019ten olu\u015fur. Bu elementlerin i\u00e7eri\u011fi \u00f6nemli d\u00fczeyde oldu\u011funda, \u03b3-Al\u2082O\u2083 i\u00e7inde ala\u015f\u0131m elementlerinin oksitlerinden olu\u015fan kat\u0131 \u00e7\u00f6zeltiler ve buna kar\u015f\u0131l\u0131k gelen spineller olu\u015fur.
\nAlkali ve alkali toprak metaller (potasyum, sodyum, baryum, lityum, kalsiyum, stronsiyum, magnezyum) ile \u00e7inko (0,05-0,1%), al\u00fcminyumun oksidasyonunu b\u00fcy\u00fck \u00f6l\u00e7\u00fcde art\u0131r\u0131r. Bunun nedeni, bu elementlerin oksitlerinin gev\u015fek ve g\u00f6zenekli yap\u0131s\u0131d\u0131r. Bu durumda olu\u015fan \u00e7ift oksit tabakas\u0131, alkali ve alkali toprak metallerin oksitleriyle zenginle\u015ftirilir. \u00c7inkonun zararl\u0131 etkilerini n\u00f6tralize etmek i\u00e7in al\u00fcminyum eriyiklerine 0,1-1,15% Mg eklenir.
\nAl\u00fcminyumun magnezyum ile olu\u015fturdu\u011fu ala\u015f\u0131mlar, de\u011fi\u015fken bile\u015fimde bir oksit tabakas\u0131 olu\u015fturur. 0,005% (k\u00fctlece) gibi d\u00fc\u015f\u00fck bir magnezyum i\u00e7eri\u011finde, oksit tabakas\u0131 \u03b3-Al\u2082O\u2083 yap\u0131s\u0131na sahiptir ve \u03b3-Al\u2082O\u2083 i\u00e7inde MgO\u2019nun bir kat\u0131 \u00e7\u00f6zeltisidir; 0,01-1,0% Mg i\u00e7eri\u011finde, oksit tabakas\u0131 de\u011fi\u015fken bile\u015fimli spinel (MgO * Al\u2082O\u2083) ve magnezyum oksit kristallerinden olu\u015fur; 1,5% Mg'den fazla i\u00e7eri\u011finde ise oksit tabakas\u0131 neredeyse tamamen magnezyum oksitten olu\u015fur.
\nBerilyum ve lantan, al\u00fcminyum ala\u015f\u0131mlar\u0131n\u0131n oksidasyonunu yava\u015flat\u0131r. 0,01% berilyum veya lantan ilavesi, Al \u2014 Mg ala\u015f\u0131mlar\u0131n\u0131n oksidasyon h\u0131z\u0131n\u0131 al\u00fcminyum oksidasyon seviyesine indirger. Bu elementlerin koruyucu etkisi, berilyum ve lantan oksitleriyle olu\u015fan g\u00f6zeneklerin doldurulmas\u0131 yoluyla oksit tabakas\u0131n\u0131n s\u0131k\u0131la\u015fmas\u0131yla a\u00e7\u0131klanmaktad\u0131r.
\nFlor ve gaz halindeki flor\u00fcrler (SiF\u2084, BF\u2083, SF\u2086 vb.), al\u00fcminyum eriyiklerinin oksitlenme e\u011filimini b\u00fcy\u00fck \u00f6l\u00e7\u00fcde azalt\u0131r.<\/p>","protected":false},"excerpt":{"rendered":"
Features of smelting aluminum alloys The smelting of most aluminum alloys is not difficult. Alloying components, with the exception of magnesium, zinc, and sometimes copper, are introduced in the form of ligatures. As a rule, protective fluxes are not used in the smelting of small…<\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[],"yoast_head":"\n