Effect of BaO on the structure and properties of bismuth-based low-melting glasses

ABSTRACT

The effect of BaO on the structure and properties of bismuth-based low-melting sealing glasses (Bi₂O₃–B₂O₃–ZnO–SiO₂–Al₂O₃–BaO) were investigated by FTIR, ²⁷Al NMR and DSC. The results showed that when BaO content was less than or equal to 3 wt-%, BaO provided (O^2–) free oxide ions, which made [AlO₆] transform into [AlO₄] and made [BO₃] transform into [BO₄]. The increase of [AlO₄] and [BO₄] enhanced the network structure and decreased the thermal expansion coefficient of glass-ceramic. But when BaO was more than 3 wt-%, a large amount of Ba²⁺ _, considered as an external body of network, entered the gap of glass network and weakened the existing bridge oxygen vibration in the glass structure and increased the thermal expansion coefficient. Besides, the crystallisation ability of glasses would be promoted by increasing the heat treatment temperature or the BaO content. The formation of BaAl₂Si₂O₈ crystal would improve the acidity resistance of the glass-ceramic to a certain extent.

KEYWORDS:

• Glass-ceramic
• low-melting glass
• sintering behaviour
• bismuth-based
• acidity resistance

Acknowledgements

This work was supported by the State Key Laboratory of Advanced Materials and Electronic Components (grant number FH2018sk201). The authors express their sincere gratitude to the ‘Material Research and Testing Center of Wuhan University of technology’.

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Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

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Funding

This work was supported by the State Key Laboratory of Advanced Materials and Electronic Components [grant number FH2018sk201].