Ultralight and high-strength bulk alumina/zirconia composite ceramic foams through direct foaming method

2019 ◽  
Vol 45 (1) ◽  
pp. 1464-1467 ◽  
Author(s):  
Wenlong Huo ◽  
Xiaoyan Zhang ◽  
Yugu Chen ◽  
Zunlan Hu ◽  
Dong Wang ◽  
...  
2020 ◽  
Author(s):  
Yu Zheng ◽  
Xudong Luo ◽  
Jiegang You ◽  
Zijun Peng ◽  
Shuhao Zhang

Abstract To satisfy the ever-increasing demands for high-performance ceramic foams that could be applied in catalysts loader, filtrations and adsorptions, it is critical to develop technologies for ceramic foams with open channel structure. In this work, we fabricated ceramic foams with three-dimensional porous structure specially with open channels by combining direct foaming method with adding pore-forming agent method. There are two levels of length scale present in this hierarchically porous structure, that is, foam structure with spherical pores evolved from bubbles, and open pores on the cell wall derived from silica hollow spheres with thin shell as the pore-former. Hierarchical ZrO 2 based foams with porosity of 86.5%-95.1% and compressive strength of 2.05-5.67 MPa, and Al 2 O 3 based foams with porosity of 86.2%-91.0% and compressive strength of 6.8-13.2 MPa were fabricated. The prepared ceramic foams characterized by this open channel structure are promising to perform outstandingly in the abovementioned fields due to their uniform pore size, low density as well as high mechanical strength.


Author(s):  
Linying Wang ◽  
Liqiong An ◽  
Jin Zhao ◽  
Shunzo Shimai ◽  
Xiaojian Mao ◽  
...  

AbstractPorous ceramics have been widely used in heat insulation, filtration, and as a catalyst carrier. Ceramics with high porosity and high strength are desired; however, this high porosity commonly results in low strength materials. In this study, porous alumina with high porosity and high strength was prepared by a popular direct foaming method based on particle-stabilized wet foam that used ammonium polyacrylate (PAA) and dodecyl trimethyl ammonium chloride (DTAC) as the dispersant and hydrophobic modifier, respectively. The effects of the dispersant and surfactant contents on the rheological properties of alumina slurries, stability of wet foams, and microstructure and mechanical properties of sintered ceramics were investigated. The microstructure of porous ceramics was regulated using wet foams to achieve high strength. For a given PAA content, the wet foams exhibited increasing stability with increasing DTAC content. The most stable wet foam was successfully obtained with 0.40 wt% PAA and 0.02 wt% DTAC. The corresponding porous alumina ceramics had a porosity of 82%, an average grain size of 0.7 µm, and a compressive strength of 39 MPa. However, for a given DTAC content, the wet foams had decreasing stability with increasing PAA content. A possible mechanism to explain these results is analyzed.


2019 ◽  
Vol 45 (2) ◽  
pp. 2124-2130 ◽  
Author(s):  
Zhongpei Du ◽  
Dongxu Yao ◽  
Yongfeng Xia ◽  
Kaihui Zuo ◽  
Jinwei Yin ◽  
...  

Magnesium ◽  
2005 ◽  
pp. 378-383 ◽  
Author(s):  
J. Zeschky ◽  
T. Höfner ◽  
J. Lo ◽  
M. Scheffler ◽  
P. Greil

2014 ◽  
Vol 602-603 ◽  
pp. 536-539
Author(s):  
Hai Bin Sun ◽  
Yu Jun Zhang ◽  
Qi Song Li

High hardness, high strength, high fracture toughness and low density are required for novel bulletproof materials. B4C/SiC composite ceramic is one of the most potential candidates. In this study, B4C/SiC composite ceramic was prepared by reaction sintering. The influence of B4C content, species and content of carbon, sintering temperature on the mechanical properties of B4C/SiC composite ceramic were studied. A high performance B4C/SiC composite ceramic was sintered at 1750°C for 30 min. Phenolic resin and carbon black were both chosen as carbon sources, whose favorable contents were 10wt%, 5wt%, respectively. The density of sintered bodies reduces with B4C content increases. To some extent, fracture toughness, bending strength improve initially and then deteriorate with the increase of B4C content whose optimal amount is 30wt%. The optimal fracture toughness and bending strength of the B4C/SiC composite ceramic are 5.07MPa·m1/2 and 487MPa, respectively. Meanwhile, the Viker-hardness of the sintered body is 30.2GPa, the density is as low as 2.82g/cm3.


2011 ◽  
Vol 197-198 ◽  
pp. 1545-1548 ◽  
Author(s):  
Qi Bing Chang ◽  
Xing Qin Liu ◽  
Xia Wang ◽  
Yong Qing Wang ◽  
Jian Er Zhou

In order to develop porous ceramics with high strength and corrosion resistance as the support for the preparation of asymmetric ceramic membranes, porous ZrO2-Al2O3 composite is designed and fabricated by adding Zr(OH)4.as sintering aid. The content of Zr(OH)4, the sintering temperature and the bending strength before and after corrosion of the composite are discussed. The results shows that 10wt% ZrO2-10wt% Zr(OH)4 -80wt%Al2O3 composite bar fabricated by cold press with the porosity of 32% can be fabricated in 1550°C for 4 h. The bending strength of the composite is 111.2MPa. After corrosion, the quality lose and the bending strength lose is no more than 1%. The tubular composite is suit for the preparation of micro-filtration membrane.


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