Fracture mode and compressive strength of ice-templated porous zirconia

Porous ceramics have separation/collection (open pore) and heat-shielding/sound-absorbing (closed pore) characteristics not found in conventional dense ceramics, increasing their industrial importance along with dense ceramics. Reticulated porous ceramics, a type of porous ceramic material, are characterized by a three-dimensional network structure having high porosity and permeability. Although there have been numerous studies of porous zirconia, which is already widely used, there are insufficient reports on reticulated porous zirconia, and it is still challenging to improve the compressive strength of reticulated porous ceramics thus far, especially considering that too few studies have been published on this topic. Therefore, we prepared reticulated porous zirconia specimens using the replica template method. In this study, the compressive strength outcomes of reticulated porous zirconia were analyzed by controlling the PPI value (25, 45, 60, and 80 PPI) of the sacrificial polymer template, the average zirconia particle size (as-received, coarse, intermediate, and fine), and the sintering temperature (1400, 1500, and 1600 °C). Consequently, we confirm that it is possible to prepare reticulated porous zirconia with a wide range of strengths (0.16~1.26 MPa) as needed with an average particle size and while properly controlling the sintering temperature.

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Fabrication and Characterization of Porous Zirconia/Alumina Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.488-489.515 ◽

2012 ◽

Vol 488-489 ◽

pp. 515-519

Author(s):

Gholamhossein Nozary ◽

Ghodratollah Roudini ◽

Ali Akbar Farashiani

Keyword(s):

Compressive Strength ◽

Ceramic Composites ◽

Effect Of Temperature ◽

Monoclinic Zirconia ◽

X Ray Diffraction ◽

Sem Images ◽

Porous Zirconia ◽

Alumina Composites ◽

Composite Samples

Porous ZrO2-Al2O3 ceramic composites containing 0, 30 and 50 wt% Al2O3 were prepared by solid state sintering in the temperature range of 1375˚-1650°C and effect of temperature and alumina percentage on compressive strength and microstructure of monoclinic zirconia was investigated by X-ray diffraction (XRD) and Scanning electron microscopy (SEM). XRD results on composite samples showed monoclinic ZrO2 and Al2O3 phases. SEM images showed uniform distribution of porosity in microstructure. Compressive strength of monoclinic zirconia improved from 33MPa to 134 MPa with adding of 50%wt alumina in sintering temperature of 1650°C.

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A Biaxial Fracture Criterion for Porous Brittle Materials

Journal of Basic Engineering ◽

10.1115/1.3605090 ◽

1968 ◽

Vol 90 (2) ◽

pp. 285-291 ◽

Cited By ~ 25

Author(s):

H. W. Babel ◽

G. Sines

Keyword(s):

Tensile Strength ◽

Compressive Strength ◽

Compressive Stress ◽

Brittle Materials ◽

Test Results ◽

Test Procedures ◽

Statistical Confidence ◽

Griffith Criterion ◽

Porous Zirconia ◽

Average Compressive Strength

The Griffith criterion for fracture of brittle materials is based on a model of a continuum in which infinitely sharp cracks are distributed with random orientations. This study extends the Griffith analysis to cracks of finite sharpness. While the Griffith criterion predicts a compressive strength of eight times the tensile strength, the extended criterion predicts a compressive strength of any value from three to eight times the tensile strength depending on the sharpness of the cracks. To test the validity of the extended criterion, tests were conducted on porous zirconia under ratios of compressive to tensile stress of 0, 3, and 5, and under compressive stress. A specimen was designed and test procedures developed so that the average bending stress was 1.99 percent. A test program was designed so that a statistical confidence limit could be assigned to the test results. The test results of the proposed criterion fell within a 99 percent confidence band, while all other criteria fell outside of the band for many combinations of tensile and compressive stress. The average compressive strength of the porous zirconia was approximately 7.1 times the tensile strength.

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Device Design of Hot-Air Curing and Study on the Properties of Hot-Air Cured Phosphate Sand

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.576.167 ◽

2014 ◽

Vol 576 ◽

pp. 167-170

Author(s):

Lu Xia ◽

Wei Long ◽

Jin Huang ◽

You Shou Zhang

Keyword(s):

Compressive Strength ◽

Fracture Surface ◽

Fracture Mode ◽

Assembly Line ◽

Design Principle ◽

High Humidity ◽

Device Design ◽

Adhesive Fracture ◽

Hot Air ◽

Sand Molding

A set of hot-air curing device for phosphate sand was designed, processed and assembled, samples were made by the device, and their properties were studied. Result shows that design principle of the device is correct, hot-air remains stable; Phosphate sand can be hardened by blowing hot-air, it is suitable to assembly line like clay sand molding line because of short blowing time, for φ30mm×30mm sample, suitable blowing time is 15s when blowing temperature is 200°C,its dry compressive strength is up to 2.1MPa; The sample is not suitable for storage, because storage strength is declined sharply with high humidity although it is improved slightly with falling humidity; Compare to no-bake phosphate sand and heat-cured phosphate sand, crack on fracture surface of hot-air cured phosphate sand is invisible nearly, but fracture mode is adhesive fracture mainly, so its dry compressive strength is lower slightly.

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The Effects of a Zirconia Addition on the Compressive Strength of Reticulated Porous Zirconia-Toughened Alumina

Applied Sciences ◽

10.3390/app11199326 ◽

2021 ◽

Vol 11 (19) ◽

pp. 9326

Author(s):

Chae-Young Lee ◽

Sujin Lee ◽

Jang-Hoon Ha ◽

Jongman Lee ◽

In-Hyuck Song ◽

...

Keyword(s):

Compressive Strength ◽

Average Particle Size ◽

Porous Ceramics ◽

Solid Loading ◽

Average Particle ◽

High Porosity ◽

Processing Conditions ◽

Porous Metals ◽

Porous Zirconia ◽

Zirconia Toughened Alumina

Porous ceramics have attracted researchers due to their high chemical and thermal stability. Among various types of porous ceramics, reticulated porous ceramics have both high porosity and good permeability. These properties of porous ceramics are difficult to replace with porous metals and polymers. ZTA is used in a variety of applications, and a wealth of experimental data has already been collected. However, research reports on reticulated porous zirconia-toughened alumina (ZTA) are insufficient. Therefore, we prepared reticulated porous ZTA via the replica template method. In this study, various processing conditions (average particle size, zirconia content, solid loading, dispersant, and thickener) were adjusted to improve the compressive strength of the reticulated porous ZTA. As a result, the optimized processing conditions for improving the compressive strength of reticulated porous ZTA could be determined.

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The influence of the addition of ground olive stone on the thermo-mechanical behavior of compressed earth blocks

Matériaux & Techniques ◽

10.1051/mattech/2020023 ◽

2020 ◽

Vol 108 (2) ◽

pp. 203

Author(s):

Samia Djadouf ◽

Nasser Chelouah ◽

Abdelkader Tahakourt

Keyword(s):

Thermal Conductivity ◽

Compressive Strength ◽

Mechanical Behavior ◽

Agricultural Waste ◽

Hydraulic Press ◽

Dry Density ◽

Olive Stone ◽

Compressed Earth Blocks ◽

Clay Matrix ◽

Earth Blocks

Sustainable development and environmental challenges incite to valorize local materials such as agricultural waste. In this context, a new ecological compressed earth blocks (CEBS) with addition of ground olive stone (GOS) was proposed. The GOS is added as partial clay replacement in different proportions. The main objective of this paper is to study the effect of GOS levels on the thermal properties and mechanical behavior of CEB. We proceeded to determining the optimal water content and equivalent wet density by compaction using a hydraulic press, at a pressure of 10 MPa. The maximum compressive strength is reached at 15% of the GOS. This percentage increases the mechanical properties by 19.66%, and decreases the thermal conductivity by 37.63%. These results are due to the optimal water responsible for the consolidation and compactness of the clay matrix. The substitution up to 30% of GOS shows a decrease of compressive strength and thermal conductivity by about 38.38% and 50.64% respectively. The decrease in dry density and thermal conductivity is related to the content of GOS, which is composed of organic and porous fibers. The GOS seems promising for improving the thermo-mechanical characteristics of CEB and which can also be used as reinforcement in CEBS.

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Variasi Penambahan Sika Cim Dan Fiber Kawat Pada Beton Mutu Fc’ 30 Mpa

Jurnal Intake : Jurnal Penelitian Ilmu Teknik dan Terapan ◽

10.32492/jintake.v9i2.776 ◽

2018 ◽

Vol 9 (2) ◽

pp. 67-73

Author(s):

M Zainul Arifin

Keyword(s):

Tensile Strength ◽

Compressive Strength ◽

Curing Temperature ◽

Test Results ◽

Concrete Compressive Strength ◽

Normal Concrete ◽

Astm Method ◽

Additive Type ◽

Composition Variation ◽

Compressive Strength Of Concrete

This research was conducted to determine the value of the highest compressive strength from the ratio of normal concrete to normal concrete plus additive types of Sika Cim with a composition variation of 0.25%, 0.50%, 0.75%, 1.00%, 1.25%, 1 , 50% and 1.75% of the weight of cement besides that in this study also aims to find the highest tensile strength from the ratio of normal concrete to normal concrete in the mixture of sika cim composition at the highest compressive strength above and after that added fiber wire with a size diameter of 1 mm in length 100 mm with a ratio of 1% of material weight. The concrete mix plan was calculated using the ASTM method, the matrial composition of the normal concrete mixture as follows, 314 kg / m3 cement, 789 kg / m3 sand, 1125 kg / m3 gravel and 189 liters / m3 of water at 10 cm slump, then normal concrete added variations of the composition of sika cim 0.25%, 0.50%, 0.75%, 1.00%, 1.25%, 1.5%, 1.75% by weight of cement and fiber, the tests carried out were compressive strength of concrete and tensile strength of concrete, normal maintenance is soaked in fresh water for 28 days at 30oC. From the test results it was found that the normal concrete compressive strength at the age of 28 days was fc1 30 Mpa, the variation in the addition of the sika cim additive type mineral was achieved in composition 0.75% of the cement weight of fc1 40.2 Mpa 30C. Besides that the tensile strength test results were 28 days old with the addition of 1% fiber wire mineral to the weight of the material at a curing temperature of 30oC of 7.5%.

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A method for measuring the in-plane compressive strength and the compression behavior of coating layers

TAPPI Journal ◽

10.32964/tj10.7.29 ◽

2011 ◽

Vol 10 (7) ◽

pp. 29-34

Author(s):

TEEMU PUHAKKA ◽

ISKO KAJANTO ◽

NINA PYKÄLÄINEN

Keyword(s):

Tensile Strength ◽

Compressive Strength ◽

Calcium Carbonate ◽

Coating Layer ◽

Test Methods ◽

Coating Films ◽

Precipitated Calcium Carbonate ◽

Coating Color ◽

Mineral Coatings ◽

Styrene Butadiene

Cracking at the fold is a quality defect sometimes observed in coated paper and board. Although tensile and compressive stresses occur during folding, test methods to measure the compressive strength of a coating have not been available. Our objective was to develop a method to measure the compressive strength of a coating layer and to investigate how different mineral coatings behave under compression. We used the short-span compressive strength test (SCT) to measure the in-plane compressive strength of a free coating layer. Unsupported free coating films were prepared for the measurements. Results indicate that the SCT method was suitable for measuring the in-plane compressive strength of a coating layer. Coating color formulations containing different kaolin and calcium carbonate minerals were used to study the effect of pigment particles’ shape on the compressive and tensile strengths of coatings. Latices having two different glass transition temperatures were used. Results showed that pigment particle shape influenced the strength of a coating layer. Platy clay gave better strength than spherical or needle-shaped carbonate pigments. Compressive and tensile strength decreased as a function of the amount of calcium carbonate in the coating color, particularly with precipitated calcium carbonate. We also assessed the influence of styrene-butadiene binder on the compressive strength of the coating layer, which increased with the binder level. The compressive strength of the coating layer was about three times the tensile strength.

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