scholarly journals Sensitivity Improvement of Thermoelectric Hydrocarbon Sensors: Combination of Glass-Ceramic Tapes and Alumina Substrates

Proceedings ◽  
2017 ◽  
Vol 1 (4) ◽  
pp. 403
Author(s):  
Jaroslaw Kita ◽  
Gunter Hagen ◽  
Christopher Schmitt ◽  
Ralf Moos
Keyword(s):  
Thermal Conductivity ◽  
Gas Sensors ◽  
Glass Ceramic ◽  
Mechanical Stability ◽  
Ceramic Materials ◽  
Functional Elements ◽  
Sensor Structure ◽  
Hydrocarbon Gas ◽  
Sensitivity Improvement ◽  
Easy Integration

This contribution presents the integration of glass-ceramic tapes on alumina substrates to increase the sensitivity of thermoelectric hydrocarbon gas sensors. Both ceramic materials have different thermal conductivity. Their combination into one sensor structure significantly improves the sensitivity by at the same time maintaining the excellent mechanical stability at high temperatures. Furthermore, this special technology allows for an easy integration of additional functional elements such as screen-printed thermocouples for temperature control purposes.

scholarly journals Thermal Conductive Networks Constructed by Sialon Fibers in-Situ Synthesized in Barium Aluminosilicate Glass-Ceramic

2021 ◽  
Author(s):  
Shaojie Sun ◽  
Xinyu Wang ◽  
Junjie Zhou ◽  
Siqi Zhang ◽  
Kongyu Ge ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Glass Ceramic ◽  
Ceramic Matrix Composite ◽  
Theoretical Models ◽  
Ceramic Materials ◽  
Aluminosilicate Glass ◽  
Complex Shapes ◽  
Barium Aluminosilicate ◽  
Enhanced Thermal Conductivity

Abstract The application of ceramic materials is limited due to the complicated preparation process and intrinsic brittleness. In this work, a pressureless manufacturing route that enables the formation of barium aluminosilicate (BAS) glass-ceramic consisting of internal β-Sialon fibers with enhanced thermal conductivity is developed. By adjusting the carbon source content, composites with different Sialon contents can be easily fabricated. The thermal conductivity of the sample with 3.5 wt.% is improved to 5.845 W/m ∙ K with the Sialon content of 26 wt.% in the composite, which is 112.64 % higher than that of the pure BAS matrix. The theoretical models suggest that the enhanced thermal conductivity is mainly ascribed to the thermal conduction network constructed by Sialon fibers. This work provides a method with industrial application prosperity to fabricate the high temperature ceramic matrix composite of different sizes and complex shapes.

scholarly journals Synthesis and characterization of low-cost glass-ceramic foams for insulating applications using glass and pumice wastes

2020 ◽  
Vol 18 (2) ◽  
Author(s):  
D. Lardizábal G. ◽  
I. Estrada Guel ◽  
J. A. Montes ◽  
K. A. Ramirez Balderrama ◽  
C. Soto Figueroa ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Glass Ceramic ◽  
Low Cost ◽  
Extreme Temperature ◽  
Ceramic Materials ◽  
Ceramic Foams ◽  
Recycled Glass ◽  
Industry Applications ◽  
Insulating Properties

At present, there is an increasing need to integrate ceramic materials with insulating properties for housing construction (for energy saving), mainly in areas where extreme temperature occurs. The objective of this work was to synthesize low-cost glass-ceramic foams, using recycled glass and waste materials near to Chihuahua city, Mexico, such as pumice and limestone mineral residues; the last one was used as a foaming material. The precursors were grounded, pressed forming pellets by cold pressing, and subsequently sintered using different conditions of temperature and time. The thermal conductivity, compressive strength, bulk density, actual density and percent expansion of prepared samples were evaluated and discussed in this work. Based on the experimentation, we found that optimum sintering time for this material is 20 minutes. Following this cheap and convenient procedure, a sample obtained at 800°C showed the best properties with a density of 0.44 g/cm3 and a thermal conductivity coefficient of 0.096 W/m K. These values indicated that is feasible to synthesize these foams construction industry applications working as appropriate thermal insulators.

An analysis of the transport properties and mechanical stability of rapidly solidified Al-Sb alloy

2015 ◽  
Vol 10 (2) ◽  
pp. 2663-2681
Author(s):  
Rizk El- Sayed ◽  
Mustafa Kamal ◽  
Abu-Bakr El-Bediwi ◽  
Qutaiba Rasheed Solaiman
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Melt Spinning ◽  
Elastic Moduli ◽  
Mechanical Stability ◽  
Microstructural Analysis ◽  
Alloy System ◽  
Antimony Content ◽  
The Stability ◽  
Rapidly Solidified

The structure of a series of AlSb alloys prepared by melt spinning have been studied in the as melt–spun ribbons  as a function of antimony content .The stability  of these structures has  been  related to that of the transport and mechanical properties of the alloy ribbons. Microstructural analysis was performed and it was found that only Al and AlSb phases formed for different composition.  The electrical, thermal and the stability of the mechanical properties are related indirectly through the influence of the antimony content. The results are interpreted in terms of the phase change occurring to alloy system. Electrical resistivity, thermal conductivity, elastic moduli and the values of microhardness are found to be more sensitive than the internal friction to the phase changes. 

scholarly journals Towards Higher Electric Conductivity and Wider Phase Stability Range via Nanostructured Glass-Ceramics Processing

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1321
Author(s):  
Tomasz K. Pietrzak ◽  
Marek Wasiucionek ◽  
Jerzy E. Garbarczyk
Keyword(s):  
Glass Ceramic ◽  
Electronic Conductivity ◽  
Glass Ceramics ◽  
Temperature Stability ◽  
Ceramic Materials ◽  
Glassy Matrix ◽  
Oxide Glasses ◽  
Thermal Transitions ◽  
Stability Range ◽  
Conductivity Enhancement

This review article presents recent studies on nanostructured glass-ceramic materials with substantially improved electrical (ionic or electronic) conductivity or with an extended temperature stability range of highly conducting high-temperature crystalline phases. Such materials were synthesized by the thermal nanocrystallization of selected electrically conducting oxide glasses. Various nanostructured systems have been described, including glass-ceramics based on ion conductive glasses (silver iodate and bismuth oxide ones) and electronic conductive glasses (vanadate-phosphate and olivine-like ones). Most systems under consideration have been studied with the practical aim of using them as electrode or solid electrolyte materials for rechargeable Li-ion, Na-ion, all-solid batteries, or solid oxide fuel cells. It has been shown that the conductivity enhancement of glass-ceramics is closely correlated with their dual microstructure, consisting of nanocrystallites (5–100 nm) confined in the glassy matrix. The disordered interfacial regions in those materials form “easy conduction” paths. It has also been shown that the glassy matrices may be a suitable environment for phases, which in bulk form are stable at high temperatures, and may exist when confined in nanograins embedded in the glassy matrix even at room temperature. Many complementary experimental techniques probing the electrical conductivity, long- and short-range structure, microstructure at the nanometer scale, or thermal transitions have been used to characterize the glass-ceramic systems under consideration. Their results have helped to explain the correlations between the microstructure and the properties of these systems.

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