A Novel Alkali and Alkaline Earth Silicate Glass for Marine Applications
Burcu ErtuÄŸ *
Department of Metallurgical and Materials Engineering, Istanbul Technical University, Ayazaga, Istanbul, Turkey
*Author to whom correspondence should be addressed.
Abstract
Aims: To test the corrosion properties of a novel alkali and alkaline earth silicate glass.
Place and Duration of Study: Department of Metallurgical and Materials Engineering, between 1999-2001.
Methodology: We included a glass which contains 75% mole lithium disilicate (Li2O.2SiO2-LS2) and 25% mole barium disilicate (BaO.2SiO2-BS2) phases. 1 mole% of P2O5 was used as nucleating agent. The scanning electron microscope (JEOL JSM-330) was used to observe the glass microstructures. X-ray diffraction (XRD) was carried out on the samples using a diffractometer (Philips PW1820) employing Cu Kα. In the chemical durability tests, the corrosive environment was boiling solutions of 0.625N HCl and 5% wt. NaOH along with boiling water. Another reference composition was also used, which included equal moles of LS2 and BS2, for the corrosion tests.
Results: When A and B glass were compared, the basic and boiling water corrosion value of B glass in terms of weight loss, (3.12; 0.38) is higher than that of A glass (4.2; 0.70). Slight differences were observed in the corrosion properties in basic and boiling water environment when A and B glass were compared. However, the weight loss of A glass in acidic environment, was 3.55% wt whereas that of B glass was determined to be 0.4% wt.
Conclusion: The chemical durability of A and B glasses against acidic environment was comparable to that of soda-lime glass. It was concluded that this novel composition is a candidate for the substitution of soda-lime glass in marine applications.
Keywords: Alkali and alkaline earth, silicate, glass, phase separation, chemical durability.