Time filter

Source Type

Deng X.,Wuhan University of Science and Technology | Deng X.,Luoyang Cen Lon Ceramics Co. | Wang J.,Wuhan University of Science and Technology | Du S.,Wuhan University of Science and Technology | And 3 more authors.
InterCeram: International Ceramic Review | Year: 2014

Porous ceramics have been extensively studied during the last two decades because of their application potentials in various fields including thermal insulators, radome materials, gas or molten metal filters, catalytic supports and biomedical substitutes for bone. This paper gives a brief review on the recent developments of preparation of porous ceramics by direct foaming method, it shows that the direct foaming method is a more effective way for preparation of high performance porous ceramics with high porosity, high mechanical strength and an even pore size distribution compared with conventional methods.


Deng X.G.,Wuhan University of Science and Technology | Deng X.G.,Luoyang Cen Lon Ceramics Co. | Wang J.K.,Wuhan University of Science and Technology | Zhang H.J.,Wuhan University of Science and Technology | And 4 more authors.
Advances in Applied Ceramics | Year: 2016

Porous mullite ceramics were prepared at 1300-1600°C for 2 h via a foam-gelcasting route using industrial-grade mullite powders as the main raw material, Isobam 104 as the dispersing and gelling agent, triethanolamine lauryl sulphate as the foaming agent and sodium carboxymethyl cellulose as the foam stabilising agent. The effects of firing temperature on the sintering behaviour of green samples as well as microstructures and properties of final porous mullite products were investigated. With increasing the temperature from 1300 to 1600°C, linear shrinkage and bulk density values of fired samples increased, whereas their porosity decreased. Mechanical strength and thermal conductivity values of fired samples decreased with increasing their porosities. Even at a porosity level as high as 79.4%, compressive and flexural strengths of fired samples (with average pore size of 314 μm) remained as high as 9.0 and 3.7 MPa, respectively, and their thermal conductivity (at 200°C) remained as low as 0.21 W (m-1 K-1). © 2016 Institute of Materials, Minerals and Mining.


Deng X.,Wuhan University of Science and Technology | Deng X.,Luoyang Cen Lon Ceramics Co. | Wang J.,Wuhan University of Science and Technology | Zhang H.,Wuhan University of Science and Technology | And 4 more authors.
Kuei Suan Jen Hsueh Pao/Journal of the Chinese Ceramic Society | Year: 2016

Mullite whiskers were synthesized at 1373-1873 K for 5 h by an in-situ solid-reaction method using Al2O3 and SiO2 as raw materials, and AlF3·3H2O as an additive. The effects of additive content and reacting temperature on the synthesis of mullite whiskers were investigated, and the growth mechanism of mullite whiskers was discussed. The results show that the length and aspect ratio of mullite whiskers with an optimal content of 4% (in mass fraction) AlF3·3H2O firstly increase, and then decrease with increasing the synthesized temperature from 1373 to 1873 K, and they have the greatest aspect ratio of 54 at 1 673 K. Mullite whiskers are formed based on the vapor-solid reaction mechanism. © 2016, Editorial Department of Journal of the Chinese Ceramic Society. All right reserved.


Deng X.,Wuhan University of Science and Technology | Deng X.,Luoyang Cen Lon Ceramics Co. | Wang J.,Wuhan University of Science and Technology | Zhang H.,Wuhan University of Science and Technology | And 2 more authors.
Key Engineering Materials | Year: 2016

Magnesium aluminate spinel (MgAl2O4) porous ceramics were in-situ synthesized by heating the mixture of Al2O3 and MgCO3 with MgCl2 salt at 1400∼1600 °C for 3 h, and then characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The morphology of as-prepared MgAl2O4 porous ceramics was dependent on the addition of MgCl2, and it indicated that the MgCl2 molten salt not only acted as a template for pore formation of the porous ceramics, but also provided a liquid environment for the synthesis of MgAl2O4. © 2016 Trans Tech Publications, Switzerland.


Deng X.,Wuhan University of Science and Technology | Deng X.,Luoyang Cen Lon Ceramics Co. | Wang J.,Wuhan University of Science and Technology | Liu J.,Wuhan University of Science and Technology | And 8 more authors.
Ceramics International | Year: 2015

Porous mullite ceramics were prepared via foam-gelcasting using industrial grade mullite powder as the main raw materials, Isobam-104 as the dispersing and gelling agent, sodium carboxymethyl cellulose as the foam stabilizing agent, and triethanolamine lauryl sulfate as the foaming agent. The effects of processing parameters such as type and amount of additive, solid loading level and gelling temperature on rheological properties and gelling behaviors of the slurries were investigated. The green samples after drying at 100 °C for 24 h were fired at 1600 °C for 2 h, and the microstructures and properties of the resultant porous ceramic samples were characterized. Based on the results, the effects of foaming agent on the porosity level, pore structure and size and mechanical properties of the as-prepared porous mullite ceramics were examined. Porosity levels and pore sizes of the as-prepared samples increased with increasing the foaming agent content up to 1.0%, above which both porosity levels and pore sizes did not change. The compressive strength and flexural strength of the as-prepared sample with porosity of 76% and average pore size of 313 μm remained as high as 15.3±0.3 MPa and 3.7±0.2 MPa, respectively, and permeability increased exponentially with increasing the porosity. © 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.


Deng X.,Wuhan University of Science and Technology | Deng X.,Luoyang Cen Lon Ceramics Co. | Wang J.,Wuhan University of Science and Technology | Huang Z.,Wuhan University of Science and Technology | And 3 more authors.
InterCeram: International Ceramic Review | Year: 2015

Porous ceramics have been extensively studied during the last two decades because of their potential application in the fields of thermal insulators, gas filters, catalytic supports, separation membranes, kiln furniture, and biomedical substitutes for bone and teeth. The properties of porous ceramics are highly dependent on their method of preparation. This mini-review summarizes recent developments in innovative fabrication of porous ceramics such as three-dimensional printing, molten salt synthesis, and the sacrificial template and replica methods. Finally, we conclude with our personal perspectives and recommendations for future research in porous ceramics.


Deng X.-G.,Wuhan University of Science and Technology | Deng X.-G.,Luoyang Cen Lon Ceramics Co. | Kong D.-C.,Wuhan University of Science and Technology | Wang J.-K.,Wuhan University of Science and Technology | And 4 more authors.
Rengong Jingti Xuebao/Journal of Synthetic Crystals | Year: 2015

ZrB2-ZrC-SiC composite powders were prepared by molten salt method using ZrSiO4, Na2B4O7, Mg, C as raw materials and MgCl2 as reaction media. The effects of reacting temperature and composition of raw materials on the phase composition and phase contents of ZrB2-ZrC-SiC composite powders were investigated. The results showed that the highest content of ZrB2-ZrC-SiC in prepared composite powders is about 78wt% under the optimum condition of MgCl2:raw materials=4:1(wt%), ZrSiO4:Na2B4O7:Mg:C=2:1:18.2:2(mol%), calcining temperature of 1150 ℃ and soaking time of 3 h. © 2015, Chinese Ceramic Society. All right reserved.

Loading Luoyang Cen Lon Ceramics Co. collaborators
Loading Luoyang Cen Lon Ceramics Co. collaborators