Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7898196 | Journal of the European Ceramic Society | 2018 | 7 Pages |
Abstract
In this work, h-BN based composites containing amorphous silica and ytterbium silicate glass phases were successfully fabricated by in situ hot pressing process. The powder mixtures of h-BN, Yb2O3, SiO2 and sintering additive (Al2O3) were hot pressed at 1880â¯Â°C for 1â¯h under 30â¯MPa in Ar atmosphere. In the composites, β-Yb2Si2O7 phase produced from the reaction between Yb2O3 and SiO2 disappears completely and transforms to Yb-Si-Al-O glass when the amount of Al2O3 is â¥1.5â¯wt.%. The Vickers hardness, flexural strength, and compressive strength reached the maximum values of 2.38â¯Â±â¯0.08â¯GPa, 337â¯Â±â¯22â¯MPa and 950â¯Â±â¯34â¯MPa, respectively, as 1.5â¯wt.% Al2O3 was added. The strengthening effects were attributed to the fine spherical microstructure of Yb-Si-Al-O glass particles, strong [AlO4] coordination state, and residual compressive stress in glass phases.
Related Topics
Physical Sciences and Engineering
Materials Science
Ceramics and Composites
Authors
Juanjuan Chen, Jixin Chen, Xi Zhang, Minmin Hu, Meishuan Li,