AUTHOR=He Wenli , Yao Chengliang , Zhao Zihan , Rong Cunren , Zhang Yanjie , Li Bing , Wu Xiuping 

TITLE=Optimization of heat treatment program and effect of heat treatment on microstructure and flexural strength of micro-nano-Li2Si2O5 whisker-reinforced glass-ceramics

JOURNAL=Frontiers in Materials

VOLUME=9

YEAR=2023

URL=https://www.frontiersin.org/journals/materials/articles/10.3389/fmats.2022.1096276

DOI=10.3389/fmats.2022.1096276

ISSN=2296-8016

ABSTRACT=<p>Lithium disilicate (Li<sub>2</sub>Si<sub>2</sub>O<sub>5</sub>, referred as LD) glass ceramics with unique aesthetic properties are ideal dental restorative materials. However, their applications are limited due to the lower flexural strength than polycrystalline ceramics. Herein, micro-nano-LD whiskers were utilized to facilitate the formation of crystallization sites and further growth of crystals in SiO<sub>2</sub>-Li<sub>2</sub>O glasses during the heat treatment process. Meanwhile, an orthogonal experiment with four-factor three-level was designed, and the optimum heat treatment conditions for preparing LD glass-ceramics with excellent flexural strength were found. The order of influencing extent of heat treatment conditions is crystallization temperature &gt; crystallization time &gt; nucleation temperature &gt; nucleation time. In addition, the crystallization behavior, phase formation, microstructure and flexural strength of glass were measured at different heat treatment temperatures. Remarkably, the optimal LD glass-ceramics sample has a strong flexural strength at 342 MPa, in which plentiful crystal grains with uniform and dense distribution are observed. These results indicate that micro-nano-LD whisker-reinforced glass-ceramics obtained by optimized heat treatment program offer a potential candidate for dental applications.</p>