z-logo
Premium
Low‐temperature preparation of high‐performance porous ceramics composed of anorthite platelets
Author(s) -
Han Lei,
Huang Liang,
Dong Longhao,
Zhang Haijun,
Pei Yuantao,
Li Faliang,
Jia Quanli,
Zhang Shaowei
Publication year - 2020
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.17265
Subject(s) - anorthite , porosity , materials science , ceramic , mineralogy , sintering , composite material , chemistry
Platelet‐like anorthite based porous ceramics with improved mechanical strength were fabricated via direct gelcasting and firing at 1223‐1473 K using CaCO 3 , Al(OH) 3 , and SiO 2 powders as the raw materials, along with H 3 BO 3 and melamine sintering/crosslinking agents. Based on density functional theory calculations, H 3 BO 3 promoted the formation of platelet‐like anorthite at a relatively low temperature via covering the {130} facet of anorthite and reducing the corresponding adsorption energy, which led to the preferential growth along the a ‐ and b ‐axes. The optimal amount of H 3 BO 3 for the anorthite platelet formation was 0.9 wt%. The porous anorthite sample with an original solid content of 22.0 wt%, after firing at 1373 K, contained 71.0% porosity and exhibited a compressive strength as high as 5.7 MPa, which were comparable or even superior to those of porous anorthite ceramics prepared previously at a much higher temperature (1573‐1723 K), indicating that the preparation strategy reported in this paper is feasible in fabricating high‐performance porous anorthite ceramics at a much milder condition. The thermal conductivity of the porous anorthite sample at 1073 K was as low as 0.266 W/(m·K), much lower than that (0.645 W/(m·K)) of the control sample, suggesting that the former could be potentially used for thermal insulation at high temperatures.

This content is not available in your region!

Continue researching here.

Having issues? You can contact us here