Preparation and Characterization of Al2O3 High Density Ceramic Materials

2013 ◽  
Vol 457-458 ◽  
pp. 266-269
Author(s):  
Chun Yan Jia ◽  
Dong Hong Li ◽  
Yong He Liu
Keyword(s):  
Sintering Temperature ◽  
Ceramic Materials ◽  
Volume Density ◽  
Raw Material ◽  
High Alumina ◽  
Molding Pressure ◽  
Alumina Powder ◽  
Alumina Ceramics ◽  
Shrinkage Ratio ◽  
Isostatic Compaction

With sub-micron alumina powder as raw material, high alumina ceramics were prepared through isostatic compaction. The volume density and shrinkage ratio were investigated. The influence of sintering temperature and molding pressure were studied on volume density and shrinkage ratio of ceramic. The results indicated that sintering characteristic of alumina ceramics could be improved at the appropriate sintering temperature and molding pressure and its sintering temperature could be decreased by using sub-micron alumina powder as raw material. 95 ceramics were prepared using sub-micron alumina as raw material, when the sintering temperature was 1550°C, molding pressure was 12 t, and ceramic volume density could be achieved 3.71g /cm3.

Low-Temperature-Tunnel of High-Alumina Ceramics with Good Wear Resistance

2014 ◽  
Vol 941-944 ◽  
pp. 538-541
Author(s):  
Jun Chang Liu ◽  
Bo Lin Wu
Keyword(s):  
Wear Resistance ◽  
Low Temperature ◽  
Wear Rate ◽  
Sintering Temperature ◽  
Raw Material ◽  
High Alumina ◽  
Alumina Ceramics ◽  
Conventional Sintering ◽  
Low Wear ◽  
Industrial Alumina

As for the liquid-phase sintered (LPS) Al2O3 based on the CaO-MgO-Al2O3-SiO2 (CMAS) system, we found a strange phenomenon. It is commonly acknowledged that, the sintering temperature should be high corresponding with the increase of the content of Al2O3 in a special system. However, when the content of Al2O3 is limited within 95-98wt%, the conclusion is opposite. It means that there is a low-temperature sintering-tunnel. What’s more, as wear resistant materials, the wear rate of alumina ceramics reduces with the increasing of the content of Al2O3 among 95-98wt%. In this paper, taking industrial alumina as raw material, we obtain low-wear-rate high-alumina ceramics by conventional sintering in CMAS system. We explain and analyze the condition from the perspective of crystalline phase and microstructure by XRD and FESEM. The results show that the 98 porcelain is of better wear resistance and indicate excellent prospect in the fabrication of lower wear rate of high-alumina ceramics.

scholarly journals SYNTHESIS AND CHARACTERIZATION OF GREENER CERAMIC MATERIALS WITH LOWER THERMAL CONDUCTIVITY USING OLIVE MILL SOLID BYPRODUCT

2020 ◽  
Vol 1 ◽  
pp. 96-106 ◽  
Author(s):  
Xenofon Spiliotis ◽  
Vayos Karayannis ◽  
Stylianos Lamprakopoulos ◽  
Konstantinos Ntampegliotis ◽  
George Papapolymerou
Keyword(s):  
Thermal Conductivity ◽  
Solid Waste ◽  
Energy Savings ◽  
Sintering Temperature ◽  
Ceramic Body ◽  
Ceramic Materials ◽  
Raw Material ◽  
Gravimetric Analysis ◽  
Olive Mill Solid Waste ◽  
Olive Mill

In the current research, the valorization of olive mill solid waste as beneficial admixture into clay bodies for developing greener ceramic materials with lower thermal conductivity, thus with increased thermal insulation capacity towards energy savings, is investigated. Various clay/waste mixtures were prepared. The raw material mixtures were characterized and subjected to thermal gravimetric analysis, in order to optimize the mineral composition and maintain calcium and magnesium oxides content to a minimum. Test specimens were formed employing extrusion and then sintering procedure at different peak temperatures. Apparent density, water absorption capability, mechanical strength, porosity and thermal conductivity were determined on sintered specimens and examined in relation to the waste percentage and sintering temperature. The experimental results showed that ceramic production from clay/olive-mill solid waste mixtures is feasible. In fact, the mechanical properties are not significantly impacted with the incorporation of the waste in the ceramic body. However, the thermal conductivity decreases significantly, which can be of particular interest for thermal insulating materials development. Furthermore, the shape of the produced ceramics does not appear to change with the sintering temperature increase.

Preparation and Investigation on Properties of the MgTiO3-CaTiO3 Microwave Ceramic Materials

2014 ◽  
Vol 997 ◽  
pp. 419-423 ◽  
Author(s):  
Li Dong ◽  
Gui Xia Dong ◽  
Yuan Yuan Li ◽  
Xi Zhang
Keyword(s):  
Dielectric Constant ◽  
Sintering Temperature ◽  
Ceramic Materials ◽  
Volume Density ◽  
Second Phase ◽  
Pressureless Sintering ◽  
Solid Reaction ◽  
Reaction Method ◽  
Microwave Ceramic ◽  
Sintering Method

The MgTiO3 and CaTiO3 powders were synthesized by solid reaction method, and MgTiO3-CaTiO3 ceramic was prepared using pressureless sintering method. The experiment prepared MgTiO3-CaTiO3 ceramics with high compactness and stable permittivity by the way of changing the mole ratio of MgTiO3 and CaTiO3 to investigate the effect of CaTiO3 on the performances of MgTiO3-CaTiO3 ceramics. The results show that Mg2TiO4 formed as second phase during sintering. Volume density and dielectric constant of MgTiO3-CaTiO3 ceramics with 10%mol CaTiO3 reach maximum of 3.612g/cm3 and 17.8, respectively, under 1460°C sintering temperature. And for the MgTiO3-CaTiO3 ceramics with 5%mol CaTiO3 the maximum values which are 3.5g/cm3 and 16.6, respectively, appear under 1510°C sintering temperature.

Effects of Adding Form of Additives on the Structure and Properties of High-Purity Alumina Ceramics

2007 ◽  
Vol 336-338 ◽  
pp. 1130-1132
Author(s):  
Qiang Ren ◽  
Xiu Lan Wu ◽  
Xuan Meng He
Keyword(s):  
High Purity ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Normal Pressure ◽  
The Body ◽  
Raw Material ◽  
Sintering Process ◽  
Alumina Ceramics ◽  
Dry Pressing ◽  
Α Al2o3

High-purity alumina ceramics was prepared using high-purity α-Al2O3 powder as raw material, nitrates or oxides of magnesium, chromium and copper as additives by a wet ball milling with a later dry pressing forming and normal pressure sintering process. The influence of additives on the sintering temperature, microstructure and bending strength of the prepared alumina ceramics was studies. The results showed that the additive doped with nitrate can be dispersed uniformly in the body with molecule scale, and the oxides obtained by decomposing of nitrates have the higher reactivity. Thus, the nitrate additives have better capacity than oxide additives in reducing the sintering temperature and inhibiting the abnormal grain growth, and the alumina ceramics prepared by adding of nitrate additives have higher density and bending strength.

Effect of Sintering Temperature on the Densification Mechanism of Al2O3-Al Metal Ceramics via the Powder Metallurgy Method

2018 ◽  
Vol 279 ◽  
pp. 104-108 ◽  
Author(s):  
Jie Guang Song ◽  
Lin Chen ◽  
Yun Xiang ◽  
Yue Liu ◽  
Xin Shuang Guo ◽  
...  
Keyword(s):  
Mass Fraction ◽  
Sintering Temperature ◽  
Mixing Time ◽  
Performance Testing ◽  
High Strength ◽  
Ceramic Materials ◽  
Powder Metallurgy Method ◽  
High Plasticity ◽  
Alumina Ceramics ◽  
Densification Mechanism

Alumina ceramics with good mechanical and corrosion resistance are the ones of the most widely used engineering ceramics. The aluminum has high strength, high conductivity and high plasticity etc. so that aluminum ceramics are used in more and more industries. In this paper, the mass fraction of 25% Al2O3 powder and the mass fraction of 75% Al powder were mixed in the blender. Mixer speed is100r/min with mixing time of 3.5 h. Forming, sintering and a series of processes for preparing the alumina/aluminum metallic ceramic materials, through performance testing and analysis, found that the density of the sample firstly increased and then decreased with the increase of sintering temperature. A melting point is close to the sintering temperature and the density of the cermet can be made relatively high. When the sintering temperature is about 600°C and 700°C, the macro performance of sample is better. The cermet is sintered at 700°C and its microstructure is relatively better.

Special Ceramic Material Based On Basaltic-Andesite for Extreme Environments

2008 ◽  
Vol 59 ◽  
pp. 39-41 ◽  
Author(s):  
Etele Albert ◽  
Marcela Muntean ◽  
A. Ianculescu ◽  
Florin Miculescu ◽  
B. Albert
Keyword(s):  
Ceramic Material ◽  
Basaltic Andesite ◽  
Complex Structure ◽  
Thermo Gravimetric Analysis ◽  
Volcanic Rocks ◽  
Extreme Environments ◽  
Ceramic Materials ◽  
Raw Material ◽  
High Alumina ◽  
Gravimetric Analysis

A special ceramic material with specific performances for some extreme environments can be elaborated using basaltic-andesite as raw material. The volcanic rocks presents specific compositions, a complex structure and properties, so some of them, such as basaltic-andesite, may have multiple utilization. The elaborated basaltic-andesite compound ceramic material, in mixture with porcelain-clay and alumina was characterized with SEM (scanning electron microscopy), EDS (energy dispersive spectroscopy), X-ray diffraction and thermo-gravimetric analysis. Many of the properties of this sort of ceramic material surpass the electric insulator porcelain type KER 110 ceramic, and in some approximate the high alumina-content ceramic materials.

scholarly journals Synergistic Sintering of Lignite Fly Ash and Steelmaking Residues towards Sustainable Compacted Ceramics

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
V. G. Karayannis ◽  
A. K. Moutsatsou ◽  
A. N. Baklavaridis ◽  
E. L. Katsika ◽  
A. E. Domopoulou
Keyword(s):  
Fly Ash ◽  
Sintering Temperature ◽  
Value Added ◽  
Mineralogical Composition ◽  
Ceramic Materials ◽  
Raw Material ◽  
Processing Temperature ◽  
Lignite Fly Ash ◽  
Experimental Findings

The development of value-added ceramic materials deriving only from industrial by-products is particularly interesting from technological, economic, and environmental point of views. In this work, the synergistic sintering of ternary and binary mixtures of fly ash, steelmaking electric arc furnace dust, and ladle furnace slag for the synthesis of compacted ceramics is reported. The sintered specimens’ microstructure and mineralogical composition were characterized by SEM-EDS and XRD, respectively. Moreover, the shrinkage, apparent density, water absorption, and Vickers microhardness (HV) were investigated at different sintering temperatures and raw material compositions. The characterization of the sintered compacts revealed the successful consolidation of the ceramic microstructures. According to the experimental findings, the ceramics obtained from fly ash/steel dust mixtures exhibited enhanced properties compared to the other mixtures tested. Moreover, the processing temperature affected the final properties of the produced ceramics. Specifically, a 407% HV increase for EAFD and a 2221% increase for the FA-EAFD mixture were recorded, by increasing the sintering temperature from 1050 to 1150°C. Likewise, a 972% shrinkage increase for EAFD and a 577% shrinkage increase for the FA-EAFD mixture were recorded, by increasing the sintering temperature from 1050 to 1150°C. The research results aim at shedding more light on the development of sustainable sintered ceramics from secondary industrial resources towards circular economy.

Effect of Molding Processing on Properties of Al2O3-Al Cermet Prepared via Powder Metallurgy Method

2018 ◽  
Vol 281 ◽  
pp. 303-308
Author(s):  
Rui Hua Wang ◽  
Xiao Bo Bai ◽  
Xiao Dong Jiang ◽  
Deng Liang Yi ◽  
Fang Wang ◽  
...  
Keyword(s):  
Powder Metallurgy ◽  
Sintering Temperature ◽  
Ceramic Materials ◽  
Molding Pressure ◽  
Initial Increase ◽  
Powder Metallurgy Method ◽  
Molding Process ◽  
Cermet Material ◽  
Pressure Time ◽  
Sample Density

Cermet while maintaining the excellent properties of ceramic materials, but also have the advantages of a metal material, is an important new engineering materials. In this paper, Al-Al2O3 cermet is prepared using different molding process via the powder metallurgy method to study the properties of Al-Al2O3 cermet. The conclusions are shown the density of the initial and late increase is not obvious with the cermet body forming pressure increases, but the increase in density of 20-30MPa is more obvious. The density of the cermet material increases with prolonging holding pressure time is shown, the initial increase speed is faster, and the later growth rate becomes weaker. In the different molding pressure, the pressure is 40MPa and 15min, sintering temperature is 700°C and 1h, the sample density is 2.084g/cm3, the highest density, the best performance, aluminum and alumina distribution is the most uniform.

Densification Mechanism of Al2O3/Al Metallic Ceramics Prepared via Powder Metallurgy Method

2017 ◽  
Vol 726 ◽  
pp. 189-193
Author(s):  
Rui Hua Wang ◽  
Yao Qi Li ◽  
Si Yuan Yu ◽  
Xiu Qin Wang ◽  
Jie Guang Song ◽  
...  
Keyword(s):  
Raw Materials ◽  
Performance Testing ◽  
High Strength ◽  
Ceramic Materials ◽  
Raw Material ◽  
Alumina Powder ◽  
Powder Metallurgy Method ◽  
High Plasticity ◽  
Pressure Time ◽  
Process Pressure

Alumina ceramics with good mechanical and corrosion resistance, is one of the most widely used engineering ceramics. The aluminum has a high strength, high conductivity, high plasticity, etc. than aluminum ceramics used in more and more industries. In this paper, aluminum and alumina powder as raw material, mixing, forming, sintering and a series of processes for preparing the alumina/aluminum metallic ceramic materials, through performance testing and analysis can be found in the ratio of raw materials 50wt% Al, 50wt % Al2O3 relatively good moldability. After sintering, after measuring the density contrast is found better density in the pressing process pressure of 20MPa and holding pressure time for 20min. By comparing the sintering process, after the interface structure by scanning electron microscopy and found help improve density through the secondary sintering metallic ceramic materials.

Improvement of Thermal Shock Resistance Performance of High Alumina Ceramic Filter Support

2013 ◽  
Vol 750-752 ◽  
pp. 525-528
Author(s):  
Yue Chao Tian ◽  
Xi Liu ◽  
Hui Tang ◽  
Jing Long Bu ◽  
Dong Mei Zhao ◽  
...  
Keyword(s):  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Bending Strength ◽  
Raw Materials ◽  
Ceramic Materials ◽  
Raw Material ◽  
Ceramic Filter ◽  
High Alumina ◽  
Gas Cleaning ◽  
Shock Resistance

Mullite-corundum multiphase ceramic materials were prepared at 1400°C for 2h with bauxite chamotte and clay clinker as raw material (size<74 μm), molded at pressure of 50 MPa. Effect of raw materials composition on sintering and themal shock resistance of composite were researched by measurements of apparent porosity, bending strength，thermal shock resistance and thermal expansion rates, and analysed by XRD and SEM. The results showed that the best weigh percentage of raw materials with better sintering and themal shock resistance are bauxite chamotte 50 wt%, clay clinker 50wt% for mullite-corundum multiphase ceramic materials. The test results for high temperature gas cleaning dust removal technology development and the application of the composite ceramic material has important application value.

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