Maganin graphitization yawanci yana buƙatar yanayin zafi mai yawa daga 2300 zuwa 3000℃, babban ƙa'idarsa ita ce canza ƙwayoyin carbon daga tsari mara kyau zuwa tsarin lu'ulu'u na graphite da aka tsara ta hanyar maganin zafi mai zafi. Ga cikakken bayani:
I. Yanayin Zafin Jiki don Maganin Graphitization na Al'ada
A. Bukatun Zafin Jiki na Asali
Grafitization na al'ada yana buƙatar ƙara yawan zafin jiki zuwa kewayon 2300 zuwa 3000℃, inda:
- 2500℃ alama ce ta babban juyi, inda tazara tsakanin atom na carbon ke raguwa sosai, kuma matakin graphitization yana ƙaruwa da sauri;
- Bayan 3000℃, canje-canje suna ƙara zama a hankali, kuma lu'ulu'u na graphite yana kusantar kamala, kodayake ƙarin yawan zafin jiki yana ƙaruwa, wanda ke rage ci gaban aiki.
B. Tasirin Bambancin Abubuwa akan Zafin Jiki
- Carbons masu sauƙin yin graphitize (misali, man fetur coke): Shiga matakin graphitization a 1700℃, tare da ƙaruwa mai mahimmanci a matakin graphitization a 2500℃;
- Yana da wahalar yin amfani da carbons (misali, anthracite): Yana buƙatar yanayin zafi mafi girma (yana kusa da 3000℃) don cimma irin wannan sauyi.
II. Tsarin da Zafin Jiki Mai Tsayi ke Haɓaka Tsarin Atom na Carbon
A. Mataki na 1 (1000–1800℃): Fitar da Iska mai Sauƙi da Tsarin Girma Biyu
- Sarkokin Aliphatic, CH, da C=O bonds suna karyewa, suna fitar da hydrogen, oxygen, nitrogen, sulfur, da sauran abubuwa a cikin nau'in monomers ko ƙwayoyin halitta masu sauƙi (misali, CH₄, CO₂);
- Layers na atom na carbon suna faɗaɗa a cikin jirgin sama mai girma biyu, tare da tsayin microcrystalline yana ƙaruwa daga 1 nm zuwa 10 nm, yayin da tarin layukan da ke tsakanin su ya kasance ba a canza shi ba;
- Tsarin endothermic (halayen sinadarai) da kuma exothermic (tsarin jiki, kamar sakin makamashin da ke tsakanin fuskoki daga ɓacewar iyaka ta microcrystalline) suna faruwa a lokaci guda.
B. Mataki na 2 (1800–2400℃): Tsarin Girma Uku da Gyaran Iyakar Hatsi
- Ƙara yawan girgizar zafin jiki na ƙwayoyin carbon yana sa su canza zuwa tsari mai girma uku, wanda ƙa'idar ƙarancin makamashi kyauta ke jagoranta;
- Rushewa da iyakokin hatsi a kan jiragen lu'ulu'u suna ɓacewa a hankali, wanda aka tabbatar ta hanyar bayyanar layuka masu kaifi (hko) da (001) a cikin siginar diffraction X-ray, yana tabbatar da samuwar shirye-shiryen da aka tsara masu girma uku;
- Wasu ƙazanta suna samar da carbide (misali, silicon carbide), waɗanda ke ruɓewa zuwa tururin ƙarfe da graphite a yanayin zafi mai girma.
C. Mataki na 3 (Sama da 2400℃): Girman Hatsi da Sake Sanyawa
- Girman hatsi yana ƙaruwa tare da axis na a zuwa matsakaicin 10-150 nm kuma tare da axis na c zuwa kimanin yadudduka 60 (kimanin 20 nm);
- Kwayoyin carbon suna yin gyaran layin ta hanyar ƙaura ta ciki ko ta tsakanin ƙwayoyin halitta, yayin da ƙimar ƙafewar abubuwan carbon ke ƙaruwa sosai yayin da zafin jiki ke ƙaruwa;
- Musayar kayan aiki tana faruwa tsakanin matakan ƙarfi da iskar gas, wanda ke haifar da samuwar tsarin lu'ulu'u mai tsari sosai.
III. Inganta Zafin Jiki ta Hanyar Tsarukan Musamman
A. Tsarin Zane-zanen Catalytic
Ƙara abubuwan kara kuzari kamar ƙarfe ko ferrosilicon na iya rage zafin graphitization sosai zuwa kewayon 1500-2200℃. Misali:
- Ferrosilicon catalyst (25% abun ciki na silicon) na iya rage zafin jiki daga 2500-3000℃ zuwa 1500℃;
- BN mai kara kuzari zai iya rage zafin jiki zuwa ƙasa da 2200℃ yayin da yake inganta yanayin zaruruwan carbon.
B. Zafin Zafi Mai Tsanani
Ana amfani da shi don aikace-aikacen tsarki kamar matakin nukiliya da graphite na matakin sararin samaniya, wannan tsari yana amfani da dumama matsakaici-mita ko dumama arc na plasma (misali, zafin jiki na tsakiya na plasma argon yana kaiwa 15,000℃) don cimma yanayin zafi sama da 3200℃ akan samfuran;
- Matsayin graphitization ya wuce 0.99, tare da ƙarancin ƙazanta sosai (ƙarin toka < 0.01%).
IV. Tasirin Zafin Jiki akan Tasirin Graphitization
A. Juriya da kuma yanayin zafi
Ga kowace ƙaruwar digirin graphitization da ta kai 0.1, juriya tana raguwa da kashi 30%, kuma juriyar zafi tana ƙaruwa da kashi 25%. Misali, bayan an yi magani a 3000℃, juriyar graphite na iya raguwa zuwa 1/4–1/5 na ƙimar farko.
B. Kayayyakin Inji
Zafin jiki mai yawa yana rage tazara tsakanin layukan graphite zuwa ƙimar da ta dace (0.3354 nm), wanda hakan ke ƙara ƙarfin juriyar girgizar zafi da kwanciyar hankali na sinadarai (tare da raguwar yawan faɗaɗawa tsakanin layukan 50%–80%), yayin da kuma ke ba da man shafawa da juriyar lalacewa.
C. Inganta Tsarkaka
A zafin 3000℃, haɗin sinadarai a cikin kashi 99.9% na mahaɗan halitta yana lalacewa, yana ba da damar fitar da ƙazanta a cikin nau'in gas kuma yana haifar da tsarkin samfurin na 99.9% ko sama da haka.
Lokacin Saƙo: Satumba-11-2025