Numerical Modeling and Experimental Characterization of the Pyroplasticity in Ceramic Materials during Sintering

2010 ◽  
Vol 62 ◽  
pp. 203-208 ◽  
Author(s):  
Pasquale Bene ◽  
Danilo Bardaro ◽  
Daniela Bello ◽  
Orazio Manni
Keyword(s):  
Ceramic Material ◽  
Ceramic Materials ◽  
Constitutive Law ◽  
Beam Deflection ◽  
Firing Cycle ◽  
Experimental Characterization ◽  
Viscosity Increase ◽  
Ceramic Components ◽  
Deflection Theory ◽  
Sintering Shrinkage

The aim of the work is the study of the pyroplasticity in ceramic materials in order to simulate the deformations of complex ceramic component during sintering. A ceramic material undergoing densification can be treated as a linear viscous material. Generally, the viscosity decreases as the temperature increases, however the densification and the consequent grain growth, result in a viscosity increase. A bending creep test is proposed for measuring the change in viscosity of the ceramic material during densification. Equations, based on beam deflection theory, are derived to determine the viscosity during the whole firing cycle by measuring the deflection in the centre of specimens. In addition, dilatometric analyses are performed to measure the sintering shrinkage and the specimen density, which continuously changes during the sintering process. On the basis of an accurate experimental characterization the parameters of Maxwell viscoelastic constitutive law are derived. A numerical-experimental procedure has been adopted in order to calibrate the numerical model that, finally, has been used to predict the pyroplastic deformations of complex ceramic components.

Investigation and Characterization of Clay Mixture Feedstock for Extrusion-Based Additive Manufacturing

2020 ◽  
Author(s):  
Tawaddod Alkindi ◽  
Mozah Alyammahi ◽  
Rahmat Agung Susantyoko
Keyword(s):  
Cost Efficiency ◽  
Ceramic Materials ◽  
3D Printer ◽  
Mixing Processes ◽  
Ceramic Components ◽  
Computer Controlled ◽  
Continuous Material ◽  
Printing Speed

Abstract The extrusion-based AM technique has been recently employed for rapid ceramic components fabrication due to scalability and cost-efficiency. This paper investigated aspects of the extrusion technique to print ceramic materials. Specifically, we assessed and developed a process recipe of the formulations (the composition of water and ethanol-based clay mixtures) and mixing processes. Different clay paste formulations were prepared by varying clay, water, ethanol ratios. The viscosity of clay paste was measured using a DV3T Viscometer. Afterward, the produced clay paste was used as a feedstock for WASP Delta 60100 3D printer for computer-controlled extrusion deposition. We evaluated the quality of the clay paste based on (i) pumpability, (ii) printability, and (iii) buildability. Pressure and flow rate were monitored to assess the pumpability. The nozzle was monitored for continuous material extrusion to assess printability. The maximum layer-without-collapse height was monitored to assess the buildability. This study correlated the mixture composition and process parameters, to the viscosity of the mixture, at the same printing speed. We found that 85 wt% clay, 5 wt% water, 10 wt% ethanol paste formulation, with the viscosity of 828000 cP, 202400 cP, 40400 cP at 1, 5, and 50 rpm, respectively, demonstrates good pumpability, as well as best printability and buildability.

Joining of Ceramic Components in the Green State via LPIM

2007 ◽  
Vol 29-30 ◽  
pp. 207-210 ◽  
Author(s):  
Rolf Waesche ◽  
Carl Paulick ◽  
Gabriele Steinborn ◽  
V. Richter ◽  
M. Werner
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Bending Strength ◽  
Ceramic Materials ◽  
Alumina Powder ◽  
Second Phase ◽  
Green State ◽  
Ceramic Components ◽  
Molded Parts

It has been successfully demonstrated that ceramic materials can be joined in the green state without a second phase by using low pressure injection molded parts. The investigation of the joining interface revealed that a high quality interface can be achieved by carefully adjusting the different manufacturing steps. The use of monomodal particle size distribution in the used powder CT3000SG is inferior to a broader particle size distribution obtained by replacing 33% of the finer alumina powder by coarser CT1200SG. In this way the dewaxing process is significantly improved when the wall thickness of the part exceeds 3 mm. The investigation of the mechanical properties of the joined and sintered parts revealed, that the bending strength of the joined specimens achieved about 80 % of the unjoined, monolithic specimens.

Application of Focus-Variation Technique in the Analysis of Ceramic Chips

2019 ◽  
Vol 957 ◽  
pp. 187-194
Author(s):  
Roman Wdowik ◽  
Slawomir Swirad
Keyword(s):  
Machine Tool ◽  
Ceramic Material ◽  
Microscopic Study ◽  
Ceramic Materials ◽  
Software Tools ◽  
Milling Machine ◽  
Focus Variation ◽  
3D Scans ◽  
Physical Phenomena ◽  
Variation Technique

The paper presents the method of a microscopic study of ceramic chips which can be useful in the analysis of physical phenomena regarding machining of ceramic materials. The analyzed chips were obtained on the milling machine tool from the Al2O3 based ceramic material. The measurements were performed using focus-variation technique (FVT). The InfiniteFocus Real3D microscope from Alicona Imaging company was applied. The paper mainly focuses on the methodology of measurements and the application of microscope’s software tools which can be used in the analysis of chips' 3D scans. The conditions of measurement process are discussed on the basis of the results of exemplary measurements of ceramic chips.

scholarly journals Treatment of Soil Contaminated by Mining Activities to Prevent Contamination by Encapsulation in Ceramic Construction Materials

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6740
Author(s):  
Juan María Terrones-Saeta ◽  
Jorge Suárez-Macías ◽  
Antonio Bernardo-Sánchez ◽  
Laura Álvarez de Prado ◽  
Marta Menéndez Fernández ◽  
...  
Keyword(s):  
Ceramic Material ◽  
Contaminated Soil ◽  
Toxic Elements ◽  
Construction Materials ◽  
Well Being ◽  
Ceramic Materials ◽  
Potentially Toxic Elements ◽  
Raw Material ◽  
Mining District ◽  
Different Soils

Mining is an essential activity for obtaining materials necessary for the well-being and development of society. However, this activity produces important environmental impacts that must be controlled. More specifically, there are different soils near new or abandoned mining productions that have been contaminated with potentially toxic elements, and currently represent an important environmental problem. In this research, a contaminated soil from the mining district of Linares was studied for its use as a raw material for the conforming of ceramic materials, bricks, dedicated to construction. Firstly, the contaminated soil was chemically and physically characterized in order to evaluate its suitability. Subsequently, different families of samples were conformed with different percentages of clay and contaminated soil. Finally, the conformed ceramics were physically and mechanically characterized to examine the variation produced in the ceramic material by the incorporation of the contaminated soil. In addition, in this research, leachate tests were performed according to the TCLP method determining whether encapsulation of potentially toxic elements in the soil occurs. The results showed that all families of ceramic materials have acceptable physical properties, with a soil percentage of less than 80% being acceptable to obtain adequate mechanical properties and a maximum of 70% of contaminated soil to obtain acceptable leachate according to EPA regulations. Therefore, the maximum percentage of contaminated soil that can be incorporated into the ceramic material is 70% in order to comply with all standards. Consequently, this research not only avoids the contamination that contaminated soil can produce, but also valorizes this element as a raw material for new materials, avoiding the extraction of clay and reducing the environmental impact.

scholarly journals Effect of LiNbO3 on the Electrocaloric Performance of 0.94BNT-0.06BT Ceramic Materials

2021 ◽  
Author(s):  
Jing Chen ◽  
lei Wu ◽  
Luanfan Duan ◽  
Dongren Liu
Keyword(s):  
Ceramic Material ◽  
Room Temperature ◽  
Ceramic Materials ◽  
Adiabatic Temperature ◽  
Cooling Effect ◽  
Material System ◽  
Temperature Changes ◽  
Cooling Temperature ◽  
Temperature Range

Abstract Considering that the electric refrigeration temperature range of 0.94BNT-0.06BT ceramic materials is 100 ~ 140℃, the electric refrigeration performance of the 0.94BNT-0.06BT ceramic material system was modified by LiNbO3 doping to reduce the cooling temperature. As a result, the refrigeration temperature range of the 0.94BNT-0.06BT ceramic material system was lowered to 25 ~ 80℃, achieving its cooling effect near room temperature, and in this temperature range, the adiabatic temperature changes ∆T > 0.6K.

Preparation of Macroporous Ceramic Materials by Using Aluminium Powder as Foaming Agent

2014 ◽  
Vol 699 ◽  
pp. 336-341 ◽  
Author(s):  
Nurulfazielah Nasir ◽  
Ridhwan Jumaidin ◽  
Hady Efendy ◽  
Mohd Zulkefli Selamat ◽  
Goh Keat Beng ◽  
...  
Keyword(s):  
Ceramic Material ◽  
Reaction Rate ◽  
Porous Alumina ◽  
Porous Ceramic ◽  
Ceramic Materials ◽  
Calcium Sulphate ◽  
Alumina Ceramic ◽  
Deionized Water ◽  
Foaming Agent ◽  
Aluminium Powder

Aluminium powder was used as foaming agent in the production of macro-porous alumina ceramic. The porous ceramic material was developed by mixing an appropriate composition of cement, aluminium powder (Al), alumina (Al2O3), calcium oxide (CaO), gypsum (calcium sulphate dehydrate, CaSO4.2H2O), silica powder and deionized water. Different compositions of porous ceramic were produced at 2wt.%, 3wt.% and 4wt.% of aluminium powder. Their mechanical properties and macro-porosity structural of the porous ceramic material were analysed and compared. It is determined that the optimal properties of porous ceramic material were found at 3wt.% of aluminium powder and degraded drastically at 4wt.%. This phenomenon is due to the chemical reaction between the aluminium powder and DI water in which they form aluminium oxide that promotes the strength of the material but at the same time, more pores are created at higher reaction rate between these two fundamental materials.

Próteses parciais fixas metal free em região posterior – revisão da literatura considerando a longevidade, material cerâmico usado e principais falhas

2021 ◽  
Vol 12 (47) ◽  
pp. 113-125
Author(s):  
Nathalia Silveira Finck ◽  
Juliana da Mota Paiva ◽  
Rafael Dario Werneck ◽  
Mariana Itaborai Moreira Freitas ◽  
Priscilla Santos Guimarães
Keyword(s):  
Ceramic Material ◽  
Ceramic Materials ◽  
Inclusion Criteria ◽  
Electronic Library ◽  
Metal Free ◽  
Significant Difference ◽  
Bibliographical Survey ◽  
Observation Period

This study aimed to present a literature review with data obtained in vitro and in vivo on metal free partial fixed protheses (PFP) in the posterior region, considering the following variables: ceramic material to be used; prosthesis extension; survival or longevity; main failures found, and comparison with the longevity of conventional metaloceramic PFP. A bibliographical survey was carried out using the databases: United States National Library of Medicine (PubMed) and Scientific Electronic Library Online (Sciello) for articles in English and Portuguese from 1998 to 2019. Articles should meet the inclusion criteria, which were articles that contained information that enabled the calculation of PFPs survival and success, articles with a minimum observation period of 3 years, articles that identified the reason of failures, and studies reported since 1998. Sixteen studies met the inclusion criteria and were evaluated comparatively. The survival rate of the PFP’s varies depending on the ceramic material used and the prostheses extension, no significant difference was observed in the relation between the ceramic material used and the connectors size; however, the greater the extension of the prosthesis, the higher must be the connector size. It was concluded that ceramic materials based on zirconia are the ones that have the longest survival. In addition, the main reasons that lead to decreased survival of PFP’s are secondary caries and connector fracture, however, more studies are needed to determine safely which materials and the extent of PFP’s are the most indicated.

Long-Haul Endurance

2002 ◽  
Vol 124 (08) ◽  
pp. 50-51
Author(s):  
John DeGaspari
Keyword(s):  
National Laboratory ◽  
Argonne National Laboratory ◽  
Ceramic Materials ◽  
Heavy Duty ◽  
Laser Technique ◽  
Early Failure ◽  
Heavy Duty Truck ◽  
Ceramic Components ◽  
Better Than

This article reviews that lasers are being investigated as a way to uncover tiny imperfections in crucial ceramic components of diesel engines. Heavy-duty truck engines are designed to operate for a million miles or more. In their search for components that resist corrosion and wear, manufacturers have developed engine parts from ceramics, which have found their way into a number of commercial engine applications over the last 10 years. Under some conditions, the materials hold up better than steel, but they are not immune to weaknesses of their own. The machining of ceramic parts, for example, can leave them with flaws that lead to early failure and defeat their purpose. The laser technique being developed at Argonne National Laboratory is intended to inspect the quality of ceramic parts after they are machined. So far, the laser technique has been developed to look for imperfections in silicon nitride, silicon carbide, and zirconia, among other ceramic materials.

Status of the Automotive Ceramic Gas Turbine Development Program: Year Five Progress

1996 ◽  
Author(s):  
Tsubura Nisiyama ◽  
Norio Nakazawa ◽  
Masafumi Sasaki ◽  
Masumi Iwai ◽  
Haruo Katagiri ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Development Program ◽  
Ceramic Materials ◽  
Inlet Temperature ◽  
Test Rig ◽  
Target Values ◽  
Ceramic Components ◽  
Combined Test ◽  
And Performance ◽  
The Individual

Petroleum Energy Center of Japan has been carrying out a 7-year development program to prove the potential of an automotive ceramic gas turbine for five years with the support of the Ministry of International Trade and Industry. The ceramic gas turbine now under development is a regenerative single shaft engine. The output is 100kW, and the turbine inlet temperature (TIT) is 1350°C. All the ceramic components are now entering the 1350°C TIT test phase after completing 1200°C TIT evaluation tests, including durability tests, in various types of test rigs. The compressor-turbine combined test rig and the full assembly test rig which is the same as an actual engine and incorporates all the components are now going through 1200°C TIT function and performance evaluation tests. In the near future, we are planning to increase the TIT to 1350°C. In consideration of the current level of high-temperature, long-term strength available from the ceramic materials, we decided to change the rated speed to 100,000 rpm because the initial rated speed of 110,000 rpm, if unchanged, involves considerable risks. Then we reviewed mainly the designs of the compressor and turbine and revised the target values of the individual components to match the specifications that satisfy the target performance of the engine.

Sign in / Sign up

Export Citation Format

Share Document