scholarly journals Effect of microsilica content on microstructure and properties of foamed ceramics with needle-like mullite

2019 ◽  
Vol 13 (2) ◽  
pp. 202-209 ◽  
Author(s):  
Wenying Zhou ◽  
Wen Yan ◽  
Nan Li ◽  
Yuanbing Li ◽  
Yajie Dai ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Raw Materials ◽  
Average Pore Size ◽  
High Porosity ◽  
Sintering Process ◽  
Average Pore ◽  
Linear Change ◽  
Direct Foaming Method ◽  
Industrial Alumina

In this study, five foamed ceramics with struts containing needle-like mullite were prepared by direct-foaming method using white clay, industrial alumina and microsilica powder as raw materials. The effects of microsilica content on the phase compositions, microstructures and properties of foamed ceramics were investigated. The results showed that the adding of microsilica decreased the average pore size and apparent porosity and increased the compressive strength and thermal conductivity of the foamed ceramics by affecting the properties of foamed slurry and reaction sintering process. The foamed ceramics with 10 wt.% microsilica content showed the best properties with high porosity of 75.8%, positive reheating linear change, compressive strength of 1.44MPa and low thermal conductivity of 0.219W/(m?K) (at 350?C).

scholarly journals Tailoring the strength and porosity of rapid-hardening magnesia phosphate paste via the pre-foaming method

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Li-Jie Liu ◽  
Jin-Hong Li ◽  
Xiang Wang ◽  
Ting-Ting Qian ◽  
Xiao-Hui Li
Keyword(s):  
Compressive Strength ◽  
Porous Structure ◽  
Bulk Density ◽  
Sodium Silicate ◽  
Average Pore Size ◽  
Hydration Product ◽  
Polypropylene Fibers ◽  
High Porosity ◽  
Average Pore ◽  
Maximum Compressive Strength

Abstract High-porosity magnesia phosphate paste (HPMPP) was prepared via the pre-foaming method. In the pre-foaming method, sintering treatment was not required. The bulk density and maximum compressive strength of the HPMPP prepared according to the ratio of water to solids (W/So) of 0.32 reached 464.00 ± 5.00 Kg/m3 and 0.30 ± 0.05 MPa, respectively. The compressive strength increased with the increases in the addition amounts of sodium silicate and polypropylene fibers. The bulk density of HPMPP increased with the increase in the addition of sodium silicate and decreased with the increase in the addition of polypropylene fibers. Besides, the porosity of the magnesia phosphate paste increased from 79.85% to 81.27% and from 80.31% to 83.75% after the addition of sodium silicate and polypropylene fibers respectively. The highest porosity (83.75%) of the prepared HPMPP was realized under the addition proportion (sodium silicate: polypropylene fibers: solids = 0.06:0.0025:1). The average pore size of the prepared HPMPP is about 180 μm and the pore distribution range is relatively narrow. The hydration product (struvite) is combined with MgO particle one by one and then coated on the surface of bubbles. With the decrease of the water content, after breaking bubbles, the porous structure can be achieved.

The Formation of Cobalt Chromium Molybdenum (CoCrMo) Foams Fabricated by Slurry Method

2016 ◽  
Vol 840 ◽  
pp. 197-201
Author(s):  
Sufizar Ahmad ◽  
M. Rosli ◽  
Nur Suliani Abdul Manaf ◽  
Murni Faridah Mahammad Rafter ◽  
Fazimah Mat Noor
Keyword(s):  
Sintering Temperature ◽  
Average Pore Size ◽  
Sem Analysis ◽  
High Porosity ◽  
Sintering Process ◽  
Cobalt Chromium ◽  
Average Pore ◽  
Slurry Method ◽  
Cobalt Chromium Molybdenum ◽  
Orthopedic Applications

Cobalt Chromium Molybdenum (CoCrMo) is a metal that are widely used in the biomedical field of orthopedic applications. CoCrMo foam was developed in the form of a porous structure where it has a high porosity on the surface with the different pore sizes and shapes. This research is intended to produce CoCrMo foam by using slurry method and to study the effect of composition and sintering temperature on the metal foams. The slurry of CoCrMo was prepared by mixing the binder materials of Methylcellulose (CMC), Polyethylene Glycol (PEG) and distilled water for an hour. Followed by mixing and stirring the CoCrMo powder for another 1 hour until it becomes slurries. Polyurethane (PU) foam was then impregnated into the slurry and dried for a day in the oven with 60 °C. Sintering process is carried out at temperature of 1000 °C, 1100 °C and 1200 °C using a tube furnace. Then sample of CoCrMo foam was going through a shrinkage measurement, microstructure analysis by using Scanning Electron Microscope (SEM), analysis of element by using Energy Diffraction X-ray (EDX) and also the density and porosity test by using Archimedes method. The sample with the composition of 65wt% was the best result in this experiment. While sintering temperature of 1200 °C produced the highest number of porosities. The shrinkage percentage is from 2.67% to 14.13%. The density obtained is in between 1.538 g/cm3 and 2.706 g/cm3 while the percentage of porosity is from 50.284% to 78.934%. The average pore size is in the range of 249.63μm to 445.38μm. The best sintering temperature and composition to produced high porosity were on 1200 °C and 65wt%.

Preparation and Research of Porous KGM/ Collagen II Composite Cartilage Scaffolds

2013 ◽  
Vol 774-776 ◽  
pp. 949-953
Author(s):  
Ming Hua Huang ◽  
Hui Dong ◽  
Di Ru Xu ◽  
Duan Cheng Wang ◽  
Yong Shun Cui ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Pore Size ◽  
Raw Materials ◽  
Average Pore Size ◽  
Crosslinking Agent ◽  
Three Dimensional ◽  
Average Pore ◽  
Blending Method ◽  
Collagen Ii

KGM and Collagen II were selected as the main raw materials and ammonia served as the crosslinking agent to prepare the porous KGM / COLII composite cartilage scaffolds by blending method and freeze-drying method. The porosity, average pore size, compressive strength and water absorption were measured on the basis of the related standard. The scaffolds were characterized by SEM and XRD. The results show that the optimal program of preparing composite cartilage scaffolds is KGM (2g), COLII (1g), freeze temperature (-20 ° C) and ammonia (0.1 ml). The optimal cartilage scaffolds are porous three-dimensional network structures which the porosity is more than 90%; the average pore size is about 200μm; the compressive strength is about 0.75Mpa and the water absorption reaches up to 892%.

Evaluation of 5% Na2O-Incorporated Calcium Metaphosphate as a Scaffold for Tissue-Engineered Bone Regeneration

2006 ◽  
Vol 309-311 ◽  
pp. 985-988 ◽  
Author(s):  
J.H. Yoon ◽  
J.T. Kim ◽  
Eui Kyun Park ◽  
Shin Yoon Kim ◽  
Chang Kuk You ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Bone Regeneration ◽  
Average Pore Size ◽  
Ectopic Bone Formation ◽  
Cellular Reaction ◽  
Average Pore ◽  
Cellular Attachment ◽  
Ectopic Bone ◽  
Osteogenic Effect

As a part of the effort to develop a suitable scaffold for tissue-engineered bone regeneration, we modified calcium metaphosphate (CMP) ceramic with Na20 and evaluated its efficiency as a scaffold. We incorporate 5% Na20 into pure CMP and prepare for an average pore size of 250 or 450 µm average pore sizes. The incorporation of 5% Na2O caused reduced compressive strength and there was no change in biodegradability. The in vitro cellular attachment and proliferation rate, however, were slightly improved. The 5% Na2O-incorporated macroporous CMP ceramic-cell constructs treated with Emdogain induced ectopic bone formation more effectively than those without Emdogain treatment. These results suggest that the incorporation of 5% Na2O into pure CMP is not effective for improving the physical characteristics of pure CMP but it is positive for improving the cellular reaction and osteogenic effect with the addition of Emdogain.

Performance Study of Fiber Reinforced New Lightweight Insulation Materials

2013 ◽  
Vol 662 ◽  
pp. 331-334
Author(s):  
Huan Qi Zhao ◽  
Guo Zhong Li
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Bending Strength ◽  
Raw Materials ◽  
The Self ◽  
Performance Study ◽  
Foaming Agent ◽  
Insulation Materials ◽  
Influencing Mechanism ◽  
Coefficient Of Thermal Conductivity

Cement-based lightweight insulation materials were made. Cement and fly ash are main raw materials. The self-developed composite excitation agent and foaming agent are used. The method of foaming is the physical foaming. The inflection of fiber dosage on the performance of lightweight insulation materials was researched. Its influencing mechanism was discussed. Experiments show that foaming lightweight insulation materials were made with 1.22MPa bending strength, 2.95MPa compressive strength and the 0.072W/mk coefficient of thermal conductivity when the fiber mixing content is 1.2%.

scholarly journals Minimizing Drying Shrinkage and Enhancing Impermeability of Foam Concrete Modified with Epoxy Resin

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Jianqing Gong ◽  
Ke Li
Keyword(s):  
Surface Energy ◽  
Pore Size ◽  
Epoxy Resin ◽  
Average Pore Size ◽  
Drying Shrinkage ◽  
Maximum Level ◽  
High Porosity ◽  
Foam Concrete ◽  
Average Pore ◽  
Internal Pore Structure

Relatively high drying shrinkage and permeability were two of the major challenges associated with foam concrete (FC), primarily due to its high porosity nature. This study was aimed at reducing the drying shrinkage and improving the impermeability of FC by blending and modifying it with epoxy resin (EP). Extensive laboratory testing yielded an optimum content of 4.0% EP, corresponding to a minimum drying shrinkage rate of 1.47 mm/m, which was 48% lower than that of the unmodified FC. At this optimum dosage of 4.0% EP, the permeability pressure was at a maximum level of 1.4 MPa, whereas the permeability coefficient was at its lowest value of 0.75 × 10−9  mm/h. Internal pore structure and EP distribution were characterized using the scanning electron microscopy and indicated that a microgrid structure of the FC was formed internally, featuring an increase in the number of pores, a reduction in the average pore size, and a uniform pore size distribution. Similarly, surface energy measurements using the tensiometry method yielded maximum surface energy values at 4.0% EP content, which could be used to explain the reduced drying shrinkage and the enhanced impermeability characteristics of the modified FC.

Study on the Preparation and Properties of Fiber Reinforced Foamed Cement Material

2013 ◽  
Vol 327 ◽  
pp. 40-43
Author(s):  
Xiao Long Li ◽  
Guo Zhong Li
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Raw Materials ◽  
Dry Density ◽  
Fiber Reinforced ◽  
Cement Material ◽  
Insulation Materials

The ordinary portland cement was used to prepare foamed cement insulation materials by physical foaming method. The influence of different process of fiber added to the foamed cement insulation materials on its performance was studied and the optimum mix ratio of raw materials was determined. The results showed that the glass fire could be evenly dispersed in the slurry by dry adding technology and got better enhanced effect. When the dosage of glass fire was 0.9%, the performance of the foamed cement material as follows: dry density of 318 kg/m3, 3d flexural strength of 0.61MPa, 3d compressive strength of 1.05MPa, thermal conductivity of 0.065W/(m·k). The reinforce mechanism of glass fire was explored.

Effect of Borax on Lightweight Material from Cullet and Fly Ash

2016 ◽  
Vol 690 ◽  
pp. 109-113 ◽  
Author(s):  
Sutthima Sriprasertsuk ◽  
Phatthiya Suwannason ◽  
Wanna T. Saengchantara
Keyword(s):  
Thermal Conductivity ◽  
Heat Treatment ◽  
Compressive Strength ◽  
Fly Ash ◽  
Sodium Silicate ◽  
Raw Materials ◽  
Raw Material ◽  
Test Results ◽  
Heat Process ◽  
Lightweight Material

This work investigated the recycling of fly ash waste and cullet as the raw materials for lightweight bodies produced by heat treatment and using sodium silicate as the binder. Borax was mixed with fly ash and cullet, and put into the block in dimension 10x10x2 cm3. The lightweight materials thus produced were then sintered at temperature of 800 °C. Density, compressive strength and thermal conductivity were determined. Borax showed a positive sintering effect on the porosity of lightweight material during the heat process. The compressive strength of lightweight material diminished with the reduction of density and thermal conductivity. Lightweight material manufactured with borax showed the lower density and thermal conductivity accompanied by the higher compressive strength. The test results indicated that using fly ash and cullet as the raw material with borax could obtain the lightweight material, thus enhancing the possibility of its reuse in a sustainable way.

Production of Thermal Insulation Composite Material Based on Polymers

2012 ◽  
Vol 535-537 ◽  
pp. 239-242
Author(s):  
Alena Kalužová ◽  
Jan Pěnčík ◽  
Libor Matějka ◽  
Libor Matějka ◽  
Tomáš Pospíšil ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Composite Material ◽  
Thermal Insulation ◽  
Raw Materials ◽  
Sustainable Construction ◽  
Glass Waste ◽  
Particle Composite ◽  
Coefficient Of Thermal Conductivity ◽  
Uniform Dispersion

Recycling of materials is an important point of sustainable construction. The aim is to find a compromise between energy saving, economy and ecology. The contribution discusses the production of thermal insulation composite material made of polymers. Uniform dispersion of grains of foamy glass waste (filler) in polymer filling from recycled thermoplastics induces formation of particle composite. The production supports usage of secondary raw materials. Decisive properties in choosing the materials to be applied include mainly the coefficient of thermal conductivity, density, compressive strength and water absorption.

Reuse of water treatment plant sludge and dam sediment in brick-making

2001 ◽  
Vol 44 (10) ◽  
pp. 273-277 ◽  
Author(s):  
C. Huang ◽  
J.R. Pan ◽  
K.-D. Sun ◽  
C.-T. Liaw
Keyword(s):  
Compressive Strength ◽  
Water Treatment ◽  
Water Absorption ◽  
Satisfactory Result ◽  
Raw Materials ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
National Standard ◽  
Sintering Process ◽  
Water Treatment Plant Sludge

In this study, an attempt was made to use water treatment plant (WTP) sludge and dam sediment as raw materials for brick-making through the sintering process. The sinter of dam sediment fired at 1,050°C had a less than 15% ratio water absorption, and its compressive strength and bulk density met the Chinese National Standard (CNS) for first level brick. The WTP sludge sinter made under the same operating condition exhibited higher water absorption, larger shrinkage, but poorer compressive strength. When fired at 1,100°C, the shrinkage of the WTP sludge sinter was as high as 45%, although its compressive strength and water absorption of WTP sludge brick still met the standard for the first level brick. To reuse WTP sludge in an economical way, mixtures of various proportions of WTP sludge to dam sediment are used as raw materials. A satisfactory result was achieved when the ratio of the WTP sludge was less than 20% of the mixture. Results of tests indicated that the sinter of dam sediments which are fired at a temperature of 1000~1100°C has reached the requirement for tile brick.

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