Functional gradient alumina ceramic materials—Heat treatment of bodies prepared by slip casting method

The work deals with preparation of functional gradient alumina ceramics with controlled porosity by slip casting method of aqueous alumina suspension containing pore-generating agent. The sol-gel transition of AlO(OH) was employed to stabilize pore-generating agent in the suspension. The composite bodies with layers of variable porosity were prepared. Based on dilatometer measurement the admission difference of irreversible dilatation changes #αirr between compounded layers was determined in order to prepare defect free bi-layer bodies. The dependence of physical and mechanical properties of as fired composite bodies on the porosity value was expressed.

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Preparation of translucent alumina ceramic specimen using slip casting method

Journal of the Ceramic Society of Japan ◽

10.2109/jcersj2.116.409 ◽

2008 ◽

Vol 116 (1351) ◽

pp. 409-413 ◽

Cited By ~ 5

Author(s):

Chutinan PROMDEJ ◽

Sakkapas AREERAKSAKUL ◽

Varong PAVARAJARN ◽

Shigetaka WADA ◽

Thanakorn WASANAPIARNPONG ◽

...

Keyword(s):

Slip Casting ◽

Alumina Ceramic ◽

Ceramic Specimen ◽

Casting Method

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Influence research of temperature heat treatment on the microstructure of alumina ceramics

Scientific research on refractories and technical ceramics ◽

10.35857/2663-3566.120.13 ◽

2020 ◽

Vol 120 ◽

pp. 134-143

Author(s):

V. V. Martynenko ◽

Р. O. Kushchenko ◽

K. I. Kushchenko ◽

Yu. O. Krakhmal ◽

E. L. Karjakina ◽

...

Keyword(s):

Heat Treatment ◽

Moisture Content ◽

Slip Casting ◽

Microscopic Analysis ◽

Alumina Ceramic ◽

Al2o3 Content ◽

Alumina Ceramics ◽

Electron Microscopic ◽

Ceramic Samples ◽

Α Al2o3

The JSC "URIR named after A. S. Berezhnoy" developed and introduced the technology of highly refractory alumina extra-dense ceramics. It is known that, the structure and properties of alumina ceramics in many cases depend on the temperature of its heat treatment, the holding time at the final temperature, the thermal unit, and a number of other factors. In order to study the processes of structure formation during of heat treatment the microstructure of alumina ceramic samples of two compositions (composition 1 with a moisture content of 30 %, as well as with dispersing and hardening additives, and composition 2 with a moisture content of 20 % only with dispersing additive) which were made by slip casting aqueous alumina slips based on reactive alumina α–from with Al2O3 content over 99 %, specific surface ~ 9 m2/g by electron microscopic analysis was studied. It was established that, after heat treatment at 1000 °C the beginning of sintering and recrystallization of corundum grains are observed, after heat treatment at 1200 °C take place packing of structure and recrystallization of α–Al2O3. After firing at 1400 °C the microstructure of samples composition 1 is represented to a large extent by crystals of tabular corundum with a particle size ~ 0.5—5.5 μm, predominant — ~ 2.5—3.0 μm. After firing at 1400 °C the microstructure of samples composition 2 is represented — by individual particles of a rounded and oval form with a size of ~ 0.5—3.5 μm, predominant — ~ 1.5—2.0 μm which are interconnected by intercrystalline layers. The microstructure of alumina ceramic samples of both compositions after firing at 1500 °C is similar and is composed of recrystallized corundum grains with a size of ~ 0.5—5.5 μm, predominant — ~ 1.5—2.0 μm, among which there are also larger α–Al2O3 grains, with a size of ~ 2—8 μm. After firing at 1580 °C the microstructure of samples is represented by a dense fine-grained structure of well-formed practically defect-free corundum grains, with a size of ~ 0.5—3.0 μm, among which grains of ~ 5—10 μm.

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DEVELOPMENT OF TECHNOLOGICAL PARAMETERS FOR THE FORMATION OF FASTS BY THE SLIDING CASTING METHOD

Bulletin of the National Technical University KhPI Series Innovation researches in students’ scientific work ◽

10.20998/2220-4784.2021.02.03 ◽

2021 ◽

pp. 15-21

Author(s):

Karyna Bilohubkina ◽

Olena Fedorenko ◽

Ruslan Kryvobok ◽

Artem Zakharov

Keyword(s):

Solid Phase ◽

Slip Casting ◽

Ceramic Materials ◽

Charge Composition ◽

Technological Parameters ◽

Casting Method ◽

Low Viscosity ◽

Free Weight ◽

Density Factor ◽

Sufficient Strength

The materials of the article consider the effectiveness of additives for stabilization and dilution of clay-free slippers. For theproduction of radio-transparent ceramic materials of Celsius-Willemite composition, the most efficient and energy-saving methodof production is the method of slip casting. According to the charge composition, this technology is complicated by the lack of claycomponents, which shows the need to use impurities to improve the rheology of such a slip. The main characteristics of aqueousceramic slippers are density, humidity, fluidity, viscosity, density factor, rate of mass accumulation. The slip must meet thefollowing requirements: be free from foam and gas inclusions, have satisfactory fluidity under low viscosity; be aggregativelystable (characterized by the absence of aggregation, coagulation and sedimentation of solid phase particles); have a high filteringcapacity to ensure fast and defect-free weight gain; to be chemically inert, to provide sufficient strength and low shrinkage of semifinished products, as well as the possibility of their easy release from the mold.

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Sintering Behavior, Thermal Expansion, and Environmental Impacts Accompanying Materials of the Al2O3/ZrO2 System Fabricated via Slip Casting

Materials ◽

10.3390/ma14123365 ◽

2021 ◽

Vol 14 (12) ◽

pp. 3365

Author(s):

Justyna Zygmuntowicz ◽

Magdalena Gizowska ◽

Justyna Tomaszewska ◽

Paulina Piotrkiewicz ◽

Radosław Żurowski ◽

...

Keyword(s):

Thermal Expansion ◽

Life Cycle ◽

Coefficient Of Thermal Expansion ◽

Raw Materials ◽

Slip Casting ◽

Ceramic Materials ◽

Sintering Behavior ◽

Environmental Loads ◽

Practical Applications ◽

Technical Ceramics

This work focuses on research on obtaining and characterizing Al2O3/ZrO2 materials formed via slip casting method. The main emphasis in the research was placed on environmental aspects and those related to the practical use of ceramic materials. The goal was to analyze the environmental loads associated with the manufacturing of Al2O3/ZrO2 composites, as well as to determine the coefficient of thermal expansion of the obtained materials, classified as technical ceramics. This parameter is crucial in terms of their practical applications in high-temperature working conditions, e.g., as parts of industrial machines. The study reports on the four series of Al2O3/ZrO2 materials differing in the volume content of ZrO2. The sintering process was preceded by thermogravimetric measurements. The fabricated and sintered materials were characterized by dilatometric study, scanning electron microscopy, X-ray diffraction, and stereological analysis. Further, life cycle assessment was supplied. Based on dilatometric tests, it was observed that Al2O3/ZrO2 composites show a higher coefficient of thermal expansion than that resulting from the content of individual phases. The results of the life cycle analysis showed that the environmental loads (carbon footprint) resulting from the acquisition and processing of raw materials necessary for the production of sinters from Al2O3 and ZrO2 are comparable to those associated with the production of plastic products such as polypropylene or polyvinyl chloride.

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Biaxial flexural strength, crystalline structure, and grain size of new commercially available zirconia-based ceramics for dental appliances produced using a new slip-casting method

Journal of the Mechanical Behavior of Biomedical Materials ◽

10.1016/j.jmbbm.2020.104180 ◽

2020 ◽

pp. 104180

Author(s):

Jean-François Roulet ◽

Kristy Lee Schepker ◽

Andres Truco ◽

Hans-Christoph Schwarz ◽

Mateus Garcia Rocha

Keyword(s):

Grain Size ◽

Flexural Strength ◽

Crystalline Structure ◽

Slip Casting ◽

Casting Method ◽

Biaxial Flexural Strength

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Slip Casting Used as a Forming Technique for Hydroxyapatite Processing

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.720.219 ◽

2016 ◽

Vol 720 ◽

pp. 219-222 ◽

Cited By ~ 3

Author(s):

Rubens Lincoln Santana Blazutti Marçal ◽

Daniel Navarro da Rocha ◽

Marcelo Henrique Prado da Silva

Keyword(s):

Slip Casting ◽

Ceramic Materials ◽

Processing Route ◽

Ceramic Suspension ◽

Polyethylene Glycol 400 ◽

Density Measurements ◽

Hydroxyapatite Powder ◽

Heat Treated ◽

Thermal Phase ◽

Before And After

Ceramic materials have particular properties when compared to other classes of materials, exhibiting poor ductility as an example. Slip casting is a widely used ceramic forming technique, and already established in the literature and in the ceramic industry. This study aims to present slip casting as a processing route for producing hydroxyapatite (HA) struts, and show the thermal phase stability. The ceramic suspension was produced and stabilized with hydroxyapatite powder, deionized water and polyethylene glycol 400. The slip was poured into gypsum mold. The green bodies were heat treated at 900 and 1100°C. Hydroxyapatite was the only phase present in all samples, before and after heat treatments. Density measurements showed that the densification was higher for the ceramic bodies sintered at 1100°C, when compared to the ones calcined at 900°C.

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