GLASS FORMATION AND PROPERTIES OF CORDIERITE COMPOSITIONS FROM TALC-BASED NATURAL RAW MATERIALS WITH BORON OXIDE ADDITION

Yıl 2010, Cilt: 11 Sayı: 2, 115 - 124, 05.10.2010

Esin Gunay Meryem Sarıgüzel

Öz

In this study, the glass forming behaviour of cordierite compositions in MAS (MgO-Al₂O₃-SiO₂) system with added B₂O₃ content up to 3% were studied by melting the natural raw materials such as; talc, kaolin, alumina and boric acid as the source of MgO, SiO₂, Al₂O₃ and B₂O₃ respectively. XRD analysis revealed the glass formation. Optical properties of the glasses were measured using UV-VIS spectrophotometer and structural changes were monitored by using FT-IR spectrometer. Physical properties such as density, colour, thermal expansion coefficients and hardness were measured according to the standard test methods. Glasses with a green colour were produced and this was attributed to the Fe content in the glass up to 0.5% coming from talc and kaolin. The addition of B₂O₃ to the glasses increased the glass transition temperatures (T_g) values and reduced the thermal expansion coefficient values of the glasses from 5.2226 to 5.0072 (ºCx10^-6), for MAS-T-0 and MAS-T-3, respectively.

 

Keywords: Green glass, Colour, Glass-formation, Natural raw materials, Optical properties.

Anahtar Kelimeler

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BOR OKSİT İLAVESİ İLE TALK-ESASLI DOĞAL HAMMADDELERDEN KORDİYERİT CAMI OLUŞUMU VE ÖZELLİKLERİ

Öz

Bu çalışmada, SiO2, MgO, Al2O3 ve B2O3 kaynağı olarak sırasıyla kaolin, talk, alumina ve borik asit gibi doğal malzemelerin eritilmesi ve %3’e kadar B2O3 ilavesi ile MAS (MgO-Al2O3-SiO) sistemindeki kordiyerit kompozisyonlarının cam oluşturma davranışı incelenmiştir. Camların optik özellikleri UV-VIS spektrofotometre ve yapısal analizler FT-IR ile belirlenmiştir. Yoğunluk, renk, termal genleşme katsayısı ve sertlik gibi fiziksel özellikler standart test metotlarına göre ölçülmüştür. Talk ve kaolendeki %0.5’e kadar olan Fe içeriği nedeniyle, yeşil renkli camlar elde edilmiş ve B2O3 ilavesi cam geçiş sıcaklığı (Tg) değerlerini yükseltmiştir ve MAS-T-0’dan MAS-T-3’e doğru termal genleşme katsayısını 5.2226’dan 5.0072ºCx10-6’ye düşürmüştür.

Anahtar Kelimeler

Yeşil cam, Renk, Cam oluşumu, Doğal hammaddeler, Optik özellikler

Kaynakça

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