Effect of Cr2O3, Fe2O3 and TiO2 nucleants on the crystallization behaviour of SiO2-Al2O3-CaO-MgO(R2O) glass-ceramics

• Published in: Ceramics international Vol. 31; no. 1; pp. 75 - 80
• Main Authors: REZVANI, M, EFTEKHARI-YEKTA, B, SOLATI-HASHJIN, M, MARGHUSSIAN, V. K
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Science 2005
• Subjects: Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Methods of crystal growth; physics of crystal growth; Physics; Theory and models of crystal growth; physics of crystal growth, crystal morphology and orientation; Scanning electron microscopy; Additives; Crystallization; Differential thermal analysis; XRD; Experimental study; Titanium Oxides; Iron Oxides; Aluminium Oxides; Chromium Oxides; Quaternary systems; Diopside; Silicon Oxides; Calcium Oxides; Aluminosilicate glass; Glass ceramics; Magnesium Oxides; Nucleating agent
• ISSN: 0272-8842; 1873-3956
• DOI: 10.1016/j.ceramint.2004.03.037

The effects of Cr2O3, Fe2O3 and TiO2 on the crystallisation behaviour of glass compositions in the SiO2-Al2O3-CaO-MgO(R2O) system were studied by DTA, XRD and SEM. It was shown that the simultaneous addition of Cr2O3, Fe2O3 and TiO2 was more effective in inducing bulk crystallisation in these glasses. The Avrami constant, n, and activation energy for crystallisation of the most promising glass specimens were determined as 3.23 and 253.60 kJ/mol, respectively, suggesting a two-dimensional bulk crystallisation mechanism. The most suitable nucleation temperature was found to be 740 C. The main crystalline phase detected in the most promising specimens after a two-stage 3 h heat treatment at 740 C and at 885 C was an aluminium diopside. 19 refs.