Preparation of Porous ZrO2-Al2O3 Composite Ceramic with High Strength and Good Corrosion-Resistance

2011 ◽  
Vol 197-198 ◽  
pp. 1545-1548 ◽  
Author(s):  
Qi Bing Chang ◽  
Xing Qin Liu ◽  
Xia Wang ◽  
Yong Qing Wang ◽  
Jian Er Zhou
Keyword(s):  
Corrosion Resistance ◽  
Bending Strength ◽  
Sintering Temperature ◽  
High Strength ◽  
Composite Ceramic ◽  
Ceramic Membranes ◽  
Porous Ceramics ◽  
Sintering Aid ◽  
Filtration Membrane ◽  
Before And After

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.

Sintering of High-Strength Dense Al2O3 Using Rod-Like Submicron Al2O3 as Sintering Aid

2010 ◽  
Vol 105-106 ◽  
pp. 20-22
Author(s):  
Yong Qing Wang ◽  
Qi Bing Chang ◽  
Jian Er Zhou
Keyword(s):  
Bending Strength ◽  
Sintering Temperature ◽  
Slenderness Ratio ◽  
High Strength ◽  
Aluminium Isopropoxide ◽  
Sem Images ◽  
Sintering Aid ◽  
Al2o3 Powder ◽  
Crystalline Fracture ◽  
Sintering Shrinkage

Rod-like submicron Al2O3 powder was prepared by the controllable hydrolyzation of aluminium isopropoxide in streams atmosphere. XRD data show the rod-like Al2O3 has a γ- Al2O3 structure. TEM images display the length of the submicron Al2O3 is in the range of 100-300 nm and the slenderness ratio is above 10. The rod-like Al2O3 powder was added into the submicron Al2O3 (D50 = 0.5 μm, purity > 99.99%) to increase the bending strength of the sintered body and to decrease the sintering temperature. SEM images display that the Al2O3 sintered at 1450 °C with rod-like Al2O3 added has a higher density than the virgin Al2O3 and the Al2O3 grains have the trans-crystalline fracture. The bending strength of the sintered Al2O3 with 5 wt% rod-like Al2O3 added is 205 MPa, which increases 241%. A sharp shrinkage in 1300-1400 °C appeared in the sintering shrinkage curves characterized by DIL show the rod-like Al2O3 also acts as the sintering aid.

Study on Preparation of Ceramic Material and its Properties

2014 ◽  
Vol 686 ◽  
pp. 57-60
Author(s):  
Ya Li Liu
Keyword(s):  
Fly Ash ◽  
Red Mud ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Raw Materials ◽  
Porous Ceramic ◽  
High Strength ◽  
Porous Ceramics ◽  
Raw Material ◽  
High Porosity

This paper introduces the classification, properties and application of porous ceramic materials, reviewed preparation of porous ceramics. Taking fly ash and red mud as the main raw material to generate porous ceramics, the paper study the influence of different proportions of raw materials, sintering temperature, porosity of porous ceramic sample rate, bending strength, and microstructure. The results show that, fly ash and red mud proportioning and sintering temperature are the main factors that influence the structure and properties of samples. The 4# sample is a kind of high porosity and high strength quality of porous ceramics.

Preparation and Characterization of Al2O3-Kaolin Composite Porous Ceramic Used as Ceramic Membrane Support

2013 ◽  
Vol 544 ◽  
pp. 56-59 ◽  
Author(s):  
Qi Bing Chang ◽  
Ke Yang ◽  
Xia Wang ◽  
Ke Kai Cheng ◽  
Yong Qing Wang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Bending Strength ◽  
Ceramic Membrane ◽  
Sintering Temperature ◽  
Porous Ceramic ◽  
Sintering Aid ◽  
Ceramic Samples ◽  
Ceramic Support ◽  
The Common

The high sintering temperature of Al2O3 is the main reason of the high cost of the common ceramic membrane supports. To decrease the sintering temperature, kaolin and talc were chosen as sintering aid because the reaction between kaolin, talc and Al2O3 generates cordierite. The Al2O3-cordierite porous ceramic samples were sintered in the range of 1450~1510°C. The microstructure and the bending strength of the samples were characterized. The results show that the content of kaolin is no more than 8%, the bending strength of the porous ceramic sintered at 1460°C and 1510°C are 77MPa and 153MPa, respectively. The further increases of the kaolin content result in the decrease of the bending strength and the porosity. The needle-like cordierite locates in the neck of Al2O3 grains. The reaction between kaolin and Al2O3 contributes to increasing the sintering velocity. The ceramic support using cordierite as sintering aid has the acid/alkali corrosion resistance in some degree.

scholarly journals Enhanced Performance of Fly Ash-Based Supports for Low-Cost Ceramic Membranes with the Addition of Bauxite

Membranes ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 711
Author(s):  
Wan Fan ◽  
Dong Zou ◽  
Jingrui Xu ◽  
Xianfu Chen ◽  
Minghui Qiu ◽  
...  
Keyword(s):  
Fly Ash ◽  
High Performance ◽  
Bending Strength ◽  
Ceramic Membrane ◽  
Sintering Temperature ◽  
Low Cost ◽  
Pure Water ◽  
Ceramic Membranes ◽  
Mullite Phase ◽  
Optimum Balance

Support is a necessary foundation for ceramic membranes to achieve high performance. Finding the optimum balance between high performance and low cost is still a significant challenge in the fabrication of ceramic supports. In this study, low-cost fly ash-based ceramic supports with enhanced performance were prepared by the addition of bauxite. The pore structure, mechanical strength, and shrinkage of fly ash/bauxite supports could be tuned by optimizing the bauxite content and sintering temperature. When the sintering temperature and bauxite content were controlled at 1300 °C and 40 wt%, respectively, the obtained membrane supports exhibited a high pure water permeance of approximately 5.36 m3·m−2·h−1·bar−1 and a high bending strength of approximately 69.6 MPa. At the same time, the optimized ceramic supports presented a typical mullite phase and excellent resistance to acid and alkali. This work provides a potential route for the preparation of ceramic membrane supports with characteristics of low cost and high performance.

Effect of Sintering Temperature on Properties of YAG Porous Ceramics via Atmospheric Sintering Method

2018 ◽  
Vol 281 ◽  
pp. 224-229 ◽  
Author(s):  
Fang Wang ◽  
Ming Han Xu ◽  
Ai Xia Chen ◽  
Long Tao Liu ◽  
Zhi Hui Li ◽  
...  
Keyword(s):  
Sintering Temperature ◽  
Raw Materials ◽  
Porous Ceramics ◽  
Soluble Starch ◽  
Product Performance ◽  
Effect Of Temperature ◽  
Sintering Process ◽  
Molding Process ◽  
Sintering Aid ◽  
Sintering Method

YAG materials have a number of unique properties, the application is very extensive, the burn is due to the temperature is too high or the residence time at high temperatures is caused. The undercurrent is the sintering temperature is too low or the holding time is not enough, resulting in product performance is too low or too small shrinkage. In this paper, the effect of sintering temperature on properties of YAG porous ceramics was investigated. The results showed that the firing temperature of the ingredients will be different and cause the same sintering process and sintering additives content of different samples burned. The increase in the content of SiO2 in the furnish with the sintering aid tends to occur. the effect of temperature on the mechanical properties of the samples after sintering was significant, so the raw materials include 60wt%YAG, 10wt% CaO, 10wt% SiO2 and 20wt% soluble starch, the molding process in 20MPa pressure 10min, the sintering at 1500°C for 2h, the sample porosity is 42.2%, the compressive strength is 5.8MPa, the outside shape is keep intact and the better pore microstructure is shown.

Preparation and Characterization of Reaction Sintering B4C/SiC Composite Ceramic

2014 ◽  
Vol 602-603 ◽  
pp. 536-539
Author(s):  
Hai Bin Sun ◽  
Yu Jun Zhang ◽  
Qi Song Li
Keyword(s):  
Fracture Toughness ◽  
High Performance ◽  
Bending Strength ◽  
Carbon Sources ◽  
High Hardness ◽  
High Strength ◽  
Composite Ceramic ◽  
High Fracture Toughness ◽  
Reaction Sintering ◽  
High Fracture

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.

scholarly journals Electrical properties and microstructure fractal analysis of magnesium-modified aluminium-silicate ceramics

2011 ◽  
Vol 43 (2) ◽  
pp. 193-204 ◽  
Author(s):  
J. Purenovic ◽  
V.V. Mitic ◽  
Lj. Kocic ◽  
V.B. Pavlovic ◽  
V. Paunovic ◽  
...  
Keyword(s):  
Fractal Analysis ◽  
Sintering Temperature ◽  
Electrical Characterization ◽  
Porous Ceramics ◽  
Before And After ◽  
High Degree ◽  
Highly Porous ◽  
Aluminium Silicate

The addition of Mg2(NO)3 and some active additives, composed of Al salts, to the mixtures of kaolinite and bentonite can provide clay compositions which, after sintering at high temperatures, produce very porous ceramics with microcrystalline and amorphous regions and highly developed metalized surfaces (mainly with magnesium surplus). Characterization of sintered samples was done before and after treatment in ?synthetic water?, i.e. in aqueous solution of arsenic-salt. Microstructure investigations have revealed non-uniform and highly porous structure with broad distribution of grain size, specifically shaped grains and high degree of agglomeration. Electrical characterization was estimated by determining dielectric constant and electrical resistivity in function of active additives amount and sintering temperature. Fractal analysis has included determination of grain contour fractal dimension.

Low-Temperature Sintering of Porous Silicon Carbide Ceramics with H3PO4 as an Additive

2018 ◽  
Vol 281 ◽  
pp. 311-315 ◽  
Author(s):  
Tian Gu ◽  
Fei Chen ◽  
Hai Long Yuan ◽  
Qiang Shen ◽  
Lian Meng Zhang
Keyword(s):  
Phosphoric Acid ◽  
Bending Strength ◽  
Sintering Temperature ◽  
High Strength ◽  
High Porosity ◽  
Low Temperature Sintering ◽  
Sic Ceramic ◽  
Carbide Ceramics ◽  
Porous Sic ◽  
Silicon Carbide Ceramics

In this paper, the raw SiC powder is oxidized at high temperature (1000 °C for 4h), and a layer of SiO2oxide film is formed on the surface of SiC particles. By adding phosphoric acid, phosphoric acid reacts with SiO2at lower temperatures to form phosphate. Phosphate decomposition produces gas to create pores. At 1200 °C, the phosphate is completely decomposed into SiO2, and a large amount of gas is produced to prepare porous SiC ceramic with high porosity and high strength. The effects of H3PO4content on the phase composition, microstructure, porosity and mechanical properties of the prepared porous SiC ceramic were investigated. With the increase of H3PO4content, the porosity increased and the bending strength decreased. The results suggest that at the sintering temperature of 1200 °C, the porosity of the samples can reach 58.3%~71.2%, while the bending strength of them can reach 8.72~31.09 MPa.

Sintering Properties of Fused Silica/Nano-Zirconia Composite Ceramic

2013 ◽  
Vol 750-752 ◽  
pp. 81-84
Author(s):  
Yong Wu He ◽  
Jing Long Bu ◽  
Rui Sheng Wang ◽  
Dong Mei Zhao ◽  
Jun Xing Chen ◽  
...  
Keyword(s):  
Bulk Density ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Composite Ceramic ◽  
High Energy ◽  
Fused Silica ◽  
Raw Material ◽  
Composite Powders ◽  
Wet Chemical Synthesis ◽  
Sintering Properties

Zirconyl chloride was used as zirconium source and fused silica particles were used as main raw material. First of all, the composite powders were prepared by wet chemical synthesis using ammonia as the precipitator and polyethylene glycol as the dispersant. Then, fused silica nanozirconia composite ceramic containing nanometer particle zirconia with different contents (5%, 15%, 25% and 35%) were fabricated in reduction atmosphere at 1300°C, 1350°C and 1400°C for 1 h. The bulk density and bending strength were measured, microstructure was observed by SEM. The result indicated bulk density and bending strength of composite ceramic increase and microstructure becomes denser with content of zirconia increasing. Bulk density of composite ceramic increases and bending strength which reaches maximum at 1350°C firstly increases then decreases with the increase of sintering temperature. Both high sintering temperature and nanozirconia possessing high energy interface can improve the composite ceramic sintering.

Superplastically Foaming Method for Reliable Porous Ceramics

2012 ◽  
Vol 735 ◽  
pp. 109-112 ◽  
Author(s):  
Akira Kishimoto ◽  
Takahiro Nakagawa ◽  
Takashi Teranishi ◽  
Hidetaka Hayashi
Keyword(s):  
Corrosion Resistance ◽  
Thermal Insulation ◽  
Superplastic Deformation ◽  
Sintering Temperature ◽  
Porous Ceramics ◽  
Ceramic Foam ◽  
Evolved Gas ◽  
High Temperature Structural Material ◽  
Strength And Durability ◽  
Full Densification

Porous ceramics incorporates pores to improve several properties including thermal insulation, maintaining inherent ceramic properties such as corrosion resistance and large mechanical strength. Conventional porous ceramics is usually fabricated through an insufficient sintering, leading to degraded strength and durability. Contrary to this, we have innovated superplastically foaming method to make ceramic foam only in the solid state. In this method, the previously inserted foam agent evaporates after the full densification of matrix at around the sintering temperature. Closed pores expand utilizing the superplastic deformation driven by the evolved gas pressure. Based on this concept we fabricated 8mol% yttria stabirized zirconia based porous ceramics and examined the properties concerning the high temperature structural material with thermal insulation.

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