Optimizing Alumina Content in Leucite-Based Dental Glass-Ceramics: Crystallization, Microstructure, and Mechanical Properties

Khosravi, Mina; Kalantar, Mahdi

doi:10.30501/acp.2026.562110.1188

Optimizing Alumina Content in Leucite-Based Dental Glass-Ceramics: Crystallization, Microstructure, and Mechanical Properties

Document Type : Original Research Article

Authors

Mina Khosravi ¹

Mahdi Kalantar ²

¹ MS Student, Department of Mining and Metallurgical Engineering, Yazd University, Yazd, Iran.

² Professor, Department of Mining and Metallurgical Engineering, Yazd University, Yazd, Iran.

10.30501/acp.2026.562110.1188

Abstract

Leucite-based glass ceramics have attracted considerable attention in dental applications due to their optical similarity to natural dental tissues and their favorable mechanical properties. In this study, the influence of alumina content on the microstructure and physical, chemical, and mechanical properties of leucite glass ceramics was investigated. Starting materials containing 18–26 wt.% aluminum hydroxide, along with silica, sodium carbonate, potassium carbonate, and lithium carbonate, were homogenized, melted, and quenched to form glass frits. Compacted glass frit samples were subsequently heat treated and sintered at different temperatures ranging from 700 to 1000 °C. Thermal behavior, phase composition, and microstructure were evaluated using DTA, XRD, and SEM techniques, respectively. Physical and mechanical properties were characterized by measuring relative density, Vickers hardness, and flexural strength. The results indicated that the optimal heat-treatment temperatures for samples containing 18 wt.% and 22–26 wt.% aluminum hydroxide were 950 °C and 1000 °C, respectively. Increasing alumina content led to higher molten glass viscosity, delayed crystallization, and reduced sinterability of the glass frits. Consequently, alumina contents exceeding the stoichiometric amount resulted in decreased microstructural homogeneity, relative density, and mechanical properties.

Keywords

Leucite Glass-Ceramic

Alumina

Crystallization

Heat Treatment

Mechanical Properties

Subjects

Glasses & Glass-ceramics

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