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Influence of Particle Size on Nonisothermal Crystallization in a Lithium Disilicate Glass
Ist Teil von
Journal of the American Ceramic Society, 2015-03, Vol.98 (3), p.774-780
Ort / Verlag
Columbus: Blackwell Publishing Ltd
Erscheinungsjahr
2015
Quelle
Wiley-Blackwell Journals
Beschreibungen/Notizen
In this study, lithium disilicate (LS2) glass samples with different particle sizes ranging from less than 105 to 850 μm were prepared. These specimens were inserted in a Pt‐Rh DSC crucible and heated to 850°C at different rates (ϕ = 0.5–30 K/min) to identify their crystallization peaks. The activation energies for the overall crystallization (E) and the Avrami coefficient (n) were evaluated using different nonisothermal models. Specifically, n was evaluated using the Augis–Benett model and the Ozawa method, and E was evaluated using the Kissinger and Ligero methods. As expected, the coarse particles mainly crystallized in the volume, while surface crystallization was predominant in the samples with particle sizes of less than 350 μm. This result was confirmed through SEM analysis of the double stage heat‐treated samples. In contrast with previous studies, our results demonstrated that the activation energy decreased as the particle size increased. In addition, no clear correlation between the peak intensity (δTp) and the particle size was observed.