Microwave Materials for Defense and Aerospace Applications

Varghese, Jobin; Joseph, Nina; Jantunen, Heli; Behera, Santanu Kumar; Kim, H. T.; Sebastian, Mailadil Thomas

doi:10.1007/978-3-030-16347-1_9

Cited by 7 publications

(3 citation statements)

References 101 publications

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“…Such property as the melting temperature is associated with a thermoplastic polymer, while the thermoset polymer shows a dimensional behavior which is characterized by its glass transition temperature ( ). Thermoplastic polymer composites require no curing and show the unlimited shelf life, reprocess ability, lower moisture absorption, chemical inertness, higher service temperature, and high environmental tolerance compared to thermoset matrix composites, but show a relatively high viscosity and processing difficulties [26]. Even at a high filler loading (60 vol%), thermosetting composites exhibit a low porosity, but a high moisture absorption and low tensile strength.…”

Section: Polymer Materialsmentioning

confidence: 99%

Polymer Composites with Improved Dielectric Properties: A Review

Ghule

Laad

2021

Ukr. J. Phys.

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Materials exhibiting high dielectric constant (k) values find applications in capacitors, gate dielectrics, dielectric elastomers, energy storage device, while materials with low dielectric constant are required in electronic packaging and other such applications. Traditionally, high k value materials are associated with high dielectric losses, frequency-dependent dielectric behavior, and high loading of a filler. Materials with low k possess a low thermal conductivity. This creates the new challenges in the development of dielectric materials in both kinds of applications. Use of high dielectric constant filler materials increases the dielectric constant. In this study,the factors affecting the dielectric constant and the dielectric strength of polymer composites are explored. The present work aims to study the effect of various parameters affecting the dielectric properties of the materials. The factors selected in this study are the type of a polymer, type of a filler material used, size, shape, loading level and surface modification of a filler material, and method of preparation of the polymer composites. The study is focused on the dielectric enhancement of polymer nanocomposites used in the field of energy storage devices. The results show that the core-shell structured approach for high dielectric constant materials incorporated in a polymer matrix improves the dielectric constant of the polymer composite.

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Section: Polymer Materialsmentioning

confidence: 99%

Polymer Composites with Improved Dielectric Properties: A Review

Ghule

Laad

2021

Ukr. J. Phys.

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“…Electromagnetic interference shielding effectiveness (EMI SE) is considered to be an amalgamation of surface reflection of the substrate related to the mismatch of impendence in between air and absorber with varying frequency, electromagnetic energy absorption or dissipation of energy due to interaction of absorber and radiation; and electromagnetic radiation-based reflections within the substrate material due to scattering observed as a result of heterogeneity in the substrate. 3,4 The materials capable to have EMI shielding properties are increasingly gaining its importance in various sectors such as aerospace, [5][6][7] communication, medicine, [8][9][10] commercial electronics [11][12][13] and defense applications [14][15][16] due to their effectiveness in shielding these harmful electromagnetic radiations. The suitable EMI shielding materials are obviously metals but their drawbacks such as tendency to oxidize and rust, high raw material cost, higher density and non-flexibility don't make them the automatic/right choice of material for use in such applications.…”

Section: Introductionmentioning

confidence: 99%

Predicting Percolation Threshold Value of EMI SE for Conducting Polymer Composite Systems Through Different Sigmoidal Models

Rahaman

Gupta²,

Hossain

et al. 2022

J. Electron. Mater.

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Like electrical conductivity, the electromagnetic interference shielding effectiveness (EMI SE) of carbon-containing polymeric composites also goes through a transition phase known as the percolation threshold (PT). In this study, the applicability of various sigmoidal models such as Sigmoidal-Boltzmann (SB), Sigmoidal-Dose Response (SD), Sigmoidal-Hill (SH), Sigmoidal-Logistic (SL), and Sigmoidal-Logistic-1 (SL-1) to determine the PT of EMI SE has been tested for composites of ethylene vinyl acetate (EVA) copolymer and acrylonitrile butadiene rubber (NBR) matrix reinforced with various particulate and fibrous carbon fillers.It is observed that the SB and SD models predicted similar PT. On the other hand, other models reported different values when validated for any particular composite system. The difference in results of PT has been discussed in detail from a viewpoint of the benefits and vice versa of these models. Also, the classical percolation theory has been applied to determine the PT of EMI SE for comparison with the values obtained through the sigmoidal models. In order to judge the universal acceptability of these models, the EMI SE results have been tested for various polymeric composites taken from some published literature. The results indicate that all the models except the SL-1 model can be successfully applied for predicting the PT of EMI SE for polymer composites.

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“…5 Several silicate-based materials such as Mg 2 SiO 4 , MgSiO 3 , ZrSiO 4 , Cu-doped Mg 2 SiO 4 , and Zn 2 SiO 4 are well known for substrate application at microwave frequency range. [6][7][8][9] However, most of these materials cannot be used for LTCC because of their high sintering temperature. There are some known strategies for reducing the sintering temperature of these materials, which include the addition of low-melting-point glasses or the addition of lowmelting-point oxides, which can be employed in order to use these materials for LTCC application.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Microwave Dielectric Properties of BBSZ-Zinc Silicate Based Material for LTCC Applications

Deshmukh

Chaware

Ratheesh

et al. 2021

Journal of Elec Materi

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The microwave dielectric properties and microstructures of zinc silicate (Zn 2 SiO 4) ceramic with the addition of 5-20 wt.% B 2 O 3-Bi 2 O 3-SiO 2-ZnO (BBSZ) glass have been studied for low-temperature co-fired ceramic (LTCC) applications. BBSZ glass helps in reducing the sintering temperature of zinc silicate (ZS) from about 1350°C to around 900°C in the form of ZS-glass composites. The zinc silicate powder was prepared following solid-state reaction technique, while BBSZ glass was prepared by standard melting and quenching method. Expectedly, the sintering studies indicate increasing sintered density between 91% and 97% with increasing sintering temperature from 875°C to 950°C. The sintering density is also seen to increase with increasing content of BBSZ, indicating liquid-phase sintering of the composites. Higher glass content in the composite leads to increased dielectric constant as well as dielectric loss. The results indicate that ZS with the addition of 5 wt.% of BBSZ glass, sintered at 925°C for 3 h, exhibits good microwave dielectric properties with a dielectric constant (e r) of 6.5 and quality factor (Q 9 f) of 20,754 GHz, which is suitable for LTCC applications.

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Microwave Materials for Defense and Aerospace Applications

Cited by 7 publications

References 101 publications

Polymer Composites with Improved Dielectric Properties: A Review

Polymer Composites with Improved Dielectric Properties: A Review

Predicting Percolation Threshold Value of EMI SE for Conducting Polymer Composite Systems Through Different Sigmoidal Models

Synthesis and Microwave Dielectric Properties of BBSZ-Zinc Silicate Based Material for LTCC Applications

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