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

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3365
Author(s):  
Justyna Zygmuntowicz ◽  
Magdalena Gizowska ◽  
Justyna Tomaszewska ◽  
Paulina Piotrkiewicz ◽  
Radosław Żurowski ◽  
...  

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.

2014 ◽  
Vol 878 ◽  
pp. 57-65 ◽  
Author(s):  
Yuan Zhou ◽  
Jing Wei Wang ◽  
Jian Feng Bai ◽  
Wen Jie Wu

With the fast growing of printing supplies industry in Shanghai, it creates a large waste stream of obsolete printing supplies and causes great pressure on the environment. The information of remanufacturing printing supplies in Shanghai is gathered and waste stream is analyzed. As a case study of original toner cartridge and remanufacturing toner cartridge is compared in the context of life cycle methodology. The results show raw materials, energy consumption and pollution emission of the remanufactured toner cartridge are less than these of original toner cartridge. Environmental loads equitant including global warming potential, acidification potential, photo-oxidant formation potential, solid waste and fume from remanufacturing toner cartridge are cut 3.61%, 3.84%, 15.24% and 22.52% comparing to original toner cartridge. Its significance is that remanufacturing printing supplies can be more profitable and less harmful to the external environment than conventional manufacturing process. It also discusses strategies for lowering the environmental burden to promote the remanufacturing printing supplies in Shanghai.


2016 ◽  
Vol 721 ◽  
pp. 322-326
Author(s):  
Ruta Švinka ◽  
Visvaldis Svinka ◽  
Julija Bobrovik

Highly porous cordierite ceramic by using of talcum, kaolinite and γ-alumina was obtained by method of slip casting of concentrated suspension. Additives of amorphous silica and non-stabilized zirconia in the amount of 5 wt% were used. Sintering temperature of dried samples was in range of 1250 – 1450°C. All the samples contain crystalline phases of cordierite, mullite and corundum but, depending on the additives, as a result of sintering in addition forms spinel, cristobalite or zircon (ZrSiO4). Porosity of obtained materials changes in large scale from 42 to 59 per cent; it is influenced by both sintering temperature and composition. Compressive strength increases with the addition of zirconia. In comparison, compressive strength of samples without additives or with silica additive does not exceed 3.5 MPa. The increase of coefficient of thermal expansion depends both on the composition and sintering temperature. ZrO2 additive increases the coefficient of thermal expansion considerably.


2018 ◽  
Vol 766 ◽  
pp. 276-281
Author(s):  
Pranee Junlar ◽  
Thanakorn Wasanapiarnpong ◽  
Lada Punsukmtana ◽  
Noppasint Jiraborvornpongsa

Ceramic cookware can be taken a direct flame or stove top for the duration without damage. The selected materials must have low thermal expansion coefficient, high strength, low water absorption and high thermal shock resistance, reasonable in cost and easy to be produced. Cordierite and spodumene composite has been interested for ceramic cookware due to their fitted properties. In previous work, study in the cordierite-spodumene composite with low thermal expansion coefficient of 2.60 x 10-6 /°C when sintered at 1250 oC with a ratio of spodumene 60 wt% and cordierite 40 wt% can withstand the pot shape samples. However, the sample showed relatively high water absorption and low strength which was not appropriate for using in this application. In this research, mullite is added in the formula to improve strength and densification of ceramic composites. Spodumene, ball clay, calcined talc and calcined alumina are used as starting raw materials and formed by slip casting. All samples are sintered in a temperature range from 1250-1275 °C in an electric furnace. Water absorption and bulk density were tested by Archimedes method, modulus of rupture was tested by the three-point bending method, microstructure were investigated by SEM and the coefficient of thermal expansion was measured by dilatometer. It was found that the mullite phase was investigated when adding mullite more than 30 wt% in cordierite-spodumene composite.


2013 ◽  
Vol 755 ◽  
pp. 145-151
Author(s):  
M. León-Carriedo ◽  
Carlos A. Gutiérrez-Chavarría ◽  
Jose Luis Rodríguez-Galicia

In recent years there have been many studies attempting to increase the mechanical properties and reliability of structural ceramic materials; the forming methods used for this purpose are based on multi-layered materials to induce residual stress between interface layers. In this work were made monolithic and multi-layered materials manufactured by casting in plaster of Paris molds using zircon and alumina as raw materials, mechanical and microstructure characterizations were compared, founding that, indeed, the laminar designs can substantially improve the mechanical properties of manufactured materials by the compressive stress between the interface layers.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
João de Lassio ◽  
Josué França ◽  
Kárida Espirito Santo ◽  
Assed Haddad

The construction industry is increasingly concerned with improving the social, economic, and environmental indicators of sustainability. More than ever, the growing demand for construction materials reflects increased consumption of raw materials and energy, particularly during the phases of extraction, processing, and transportation of materials. This work aims to help decision-makers and to promote life cycle thinking in the construction industry. For this purpose, the life cycle assessment (LCA) methodology was chosen to analyze the environmental impacts of building materials used in the construction of a residence project in São Gonçalo, Rio de Janeiro, Brazil. The LCA methodology, based on ISO 14040 and ISO 14044 guidelines, is applied with available databases and the SimaPro program. As a result, this work shows that there is a substantial waste of nonrenewable energy, increasing global warming and harm to human health in this type of construction. This study also points out that, for this type of Brazilian construction, ceramic materials account for a high percentage of the mass of a total building and are thus responsible for the majority of environmental impacts.


2019 ◽  
Vol 4 (11) ◽  
Author(s):  
Giacomo Eramo ◽  
Annarosa Mangone

Abstract Ceramics are among the most studied findings, one of the best markers for providing technological and functional information in archaeological contexts. Their chemical-mineralogical characterization allows to answer a large number of historical-archaeological questions about classification, provenance, production technologies, trade routes, economic exchange, etc. The best methodological approach not only integrates morphological-stylistic studies to the archaeometric ones, but also includes a synergic instrumental strategy aimed both to take advantage of each different analytical technique to the best of its potentiality and to over step the problems connected to the preciousness and uniqueness of the objects. As far as the mineralogical and petrographical composition of preindustrial ceramics is concerned, its determination is crucial to answer provenance and technological issues like raw materials procurement and the production processes in this respect, equivalent firing temperature, redox atmosphere during firing are important factors that help in understanding the relevant mineralogical and micro-structural transformations. In this paper, we illustrate how an integrated approach of analytical techniques, tested on different classes of ceramics – pottery with spathic calcite, Apulian red figure pottery and technical ceramics – can provide answers to archaeological questions.


2019 ◽  
Vol 891 ◽  
pp. 214-218
Author(s):  
Jirasak Tharajak ◽  
Noppakun Sanpo

Leucite has been widely used as a constituent of dental ceramics to modify the coefficient of thermal expansion. This is most important where the ceramic is to be fused or baked onto metal. However, its physical property was unpredictable since it was sensitive to several parameters such as sintering temperature and concentration of raw materials. In this research study, leucite ceramic particles were synthesized by in-house sol-gel process. The morphology and size of our synthesized leucite particles were analyzed by SEM, vicker hardness and XRD, respectively. It was revealed that the sintering temperature played the important role on several properties of leucite ceramic particles.


2011 ◽  
Vol 66-68 ◽  
pp. 1522-1527
Author(s):  
Li Na Sui ◽  
Li Yan Yu ◽  
Li Feng Dong

Leucite crystal was prepared using SiO2-Al2O3-K2CO3-Na2CO3as raw materials and adopting melt quenching and appropriate heat treatment temperatures. The crystal was characterized and analyzed by X-ray powder diffraction, the coefficient of thermal expansion, and biocompatibility. The results showed that appropriate Na2O could advance the growth of leucite, but high concentration facilitates the formation of KAlSiO4crystal. The coefficient of thermal expansion was 24.52×10-6/°C at 600 °C, and thereby the coefficient could be adjusted by adding appropriate amount of leucite. The biocompatibility of leucite was almost the same as the Songfeng powder for clinical applications.


2008 ◽  
Vol 569 ◽  
pp. 321-324
Author(s):  
Isaías Juárez-Ramírez ◽  
Koji Matsumaru ◽  
Kozo Ishizaki ◽  
Leticia M. Torres-Martínez

Porous ceramic materials with low thermal expansion (LTE) at room temperature were prepared by heating a mixture of SiC or black-Al2O3, vitrified bonding material (VBM) and LiAlSiO4 at temperatures from 850°C to 1100°C. The mixture was prepared in adequate proportions to obtain a material with LTE according to previous works made in our laboratory. It was observed that a change in temperature provoked the formation of a new phase, LiAlSi3O8, which appears above 900°C. The presence of this new phase did not affect the thermal expansion value, keeping LTE at room temperature. All compounds showed around 40% of porosity, and Young’s modulus values of 30 GPa using black-Al2O3 or SiC. X-ray diffraction analysis (XRD) revealed that above 900°C the phase LiAlSi3O8 starts to appear as a consequence of the melting of VBM, which is reacting with the raw materials. SEM micrographs showed the presence of SiC or black-Al2O3 grains joined by VBM, which is acting as a bridge between them.


2020 ◽  
Author(s):  
Alexandra Kloužková ◽  
Martina Kohoutková ◽  
Mária Kolářová ◽  
Gabriela Blažková ◽  
Radka Ševců ◽  
...  

Abstract A series of scientific methods (X-ray analyses, optical and electron microscopy, Raman spectroscopy and thermal analyses) was used to research the ceramic bodies and glazes of forty vessels from Renaissance Prague. The set of Early Modern Age archaeological glazed ceramics contained tableware, kitchenware and technical ceramics. The main aim was to characterise ceramic materials and glazes used over two centuries. Attention was also paid to the identification of defects and corrosion products of the glazes. The research was conducted with an emphasis on the context of the original use of the ceramic artefacts and the environment of the waste pits from which they were excavated. The archaeological finds include three technical ceramic vessels (a rectifier, a bowl and a jar), which together could have formed a distillation apparatus. Since these vessels represent a rare finding, they were subjected to a detailed investigation. Based on the similarity of ceramic bodies and glazes, it was proved that the three technical ceramic vessels were made in the same workshop and were parts of one distillation apparatus. The results of the performed analyses determined that the studied vessels were manufactured from raw materials with a high content of a plastic component and that the raw materials did not change significantly during the period from the 15th to 18th centuries. The firing temperature of most of the vessels did not exceed 1000 °C. It was proved that all the glazes were medium- or high-lead content glazes and were coloured with ionic pigments.


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