Effect of the ZrO2 concentration on the crystallization behavior and the mechanical properties of high-strength MgO–Al2O3–SiO2 glass–ceramics

• Published in: Journal of materials science 2017-02, Vol.52 (4), p.1955-1968
• Main Authors: Seidel, Sabrina, Dittmer, Marc, Wisniewski, Wolfgang, Höland, Wolfram, Rüssel, Christian
• Format: Article
• Language: English
• Subjects: Aluminum oxide; Characterization and Evaluation of Materials; Chemistry and Materials Science; Classical Mechanics; Compressive properties; Cordierite; Crystallization; Crystallography and Scattering Methods; Electron backscatter diffraction; Glass ceramics; High strength; Magnesium oxide; Materials Science; Mechanical properties; Original Paper; Polymer Sciences; Scanning electron microscopy; Silicon dioxide; Solid Mechanics; Solid solutions; Substrates; Surface layers; Thermal expansion; X-ray diffraction; Zirconium dioxide
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-016-0484-5

High-strength, colorless glass–ceramics in the MgO/Al 2 O 3 /SiO 2 system with high concentrations of ZrO 2 and a great potential for technical application, e.g., as high-performance hard disc substrates, are investigated. ZrO 2 concentrations from 6 to 9 mol% are added to a stoichiometric cordierite glass to investigate the influence of the concentration of the nucleating agent on the crystallization behavior and the mechanical properties. The phase formation and the microstructure of the glass–ceramics are studied using X-ray diffraction and scanning electron microscopy including electron backscatter diffraction. It is shown that the volume crystallization of ZrO 2 , a low-/high-quartz solid solution (low-/high-QSS), and spinel is accompanied by the surface crystallization of indialite. This phase offers a much smaller coefficient of thermal expansion than the other crystal phases, which may induce high compressive stresses in the surface layer of the glass–ceramics after cooling and seems to result in excellent mechanical properties of the material. Biaxial flexural strengths of up to 1 GPa were measured. Higher ZrO 2 concentrations reduce the surface crystallization of indialite and decrease the mean size of the crystals resulting in a higher translucency. The volume-crystallizing phases and the mechanical properties of the glass–ceramics do not seem to be significantly affected by the analyzed ZrO 2 concentrations.