High quality factor cold sintered Li2MoO4BaFe12O19 composites for microwave applications

Faouri, Sinan S.; Mostaed, Ali; Dean, J.; Wang, Dawei; Sinclair, Derek C.; Zhang, Shiyu; Whittow, William G.; Vardaxoglou, Yiannis; Reaney, Ian M.

doi:10.1016/j.actamat.2018.12.057

Cited by 62 publications

(32 citation statements)

References 30 publications

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“…Recently, several studies have highlighted the possibility to fabricate ceramic-thermoplastic polymers composites by the cold sintering process (CSP). [1][2][3][4][5][6][7] The CSP is a technique that enables the fabrication of dense ceramics and ceramic-based composites at low temperature (<350°C), mainly based on a pressure solution creep mechanism (dissolution → mass transport → precipitation, following chemical potential gradients), induced by the presence of a transient liquid phase and uniaxial pressure. [8][9][10][11][12][13][14][15] CSP bridges the gap between processing temperatures of an important number of ceramics and polymers, offering a unique opportunity for the discovery, design, and fabrication of new composites with engineered grain boundaries.…”

Section: Introductionmentioning

confidence: 99%

Thermosetting polymers in cold sintering: The fabrication of ZnO‐polydimethylsiloxane composites

et al. 2020

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This study reports the fabrication of the first ceramics‐thermosetting polymer composites by the cold sintering process, for high ceramic volume fractions (v/v >95%). The (1 − x) ZnO − x polydimethylsiloxane (PDMS) composites, with 0.00 ≤ x ≤ 0.05, were cold sintered at 250°C, 320 MPa for 60 minutes. In situ densification studies conducted with the help of a semi‐automated press revealed that the mechanisms driving the densification of the material changes with the polymer content. Relative densities of the (1 − x) ZnO − x PDMS composites (0.00 ≤ x ≤ 0.05) were above 90%. Impedance spectroscopy of the composites yields insight into the ceramic‐polymer interfaces within the sintered ZnO bulk and suggests long‐range conduction governed by ZnO‐PDMS interface properties for x = 0.03 and x = 0.05. The study also emphasizes on the complexities and opportunities of such ceramic‐dominated ceramic‐polymer composites.

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Section: Introductionmentioning

confidence: 99%

Thermosetting polymers in cold sintering: The fabrication of ZnO‐polydimethylsiloxane composites

et al. 2020

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“…In 1964, Turba and Rump [9,10], using the setup shown in Figure 2(c), investigated the mechanism of cohesion in BaSO 4 powders compacted both in dry as well as moisturised conditions. For dry-pressed BaSO 4 , they concluded that Van der Waals forces were the most significant particle-particle interactions. Under wet conditions, other effects should be taken Figure 2.…”

Section: They Reportedmentioning

confidence: 99%

“…Hydrolysis is directly correlated to the ionic potential of metal ions, however, it can be suppressed by acidification of water if necessary to avoid species precipitation during CSP. For example, the CSP of ZnO occurs in acid solution because it limits hydrolysis, see Equation (4). The mechanism of dissolution precipitation preferentially involves the aqua complex Zn(H 2 O) 2+ 6 instead of hydroxides.…”

Section: Formation Of Primary Bonds In Dry Conditions and Consolidatimentioning

confidence: 99%

A review of cold sintering processes

Grasso

Biesuz

Zoli

et al. 2020

Advances in Applied Ceramics

194

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The need to reduce the energy consumed and the carbon footprint generated by firing ceramics has stimulated research to develop consolidation techniques operating at lower temperatures, ideally not exceeding 300°C. This has been realised in Ultra Low Energy Sintering (ULES) using high pressure (hundreds of MPa) in the presence of a transient liquid phase, which accelerates plasticity, grain boundary/surface diffusion and mass transport. Several ULES techniques have been developed in the past 50 years, and a common feature of all of them is low temperature consolidation, through mechanisms not yet fully understood, enabling multi-material integration (e.g. organics and inorganics). This research could transform the traditional firing of functional and structural materials. Early stage work on ULES, started in the 1960s, clearly demonstrated cohesion between the compacted particles exceeding what was possible if simply produced by Van der Waals bonding, suggesting the formation of primary inter-particle bonds. Surprisingly, metals Cold Sintered (CS) in dry conditions at room temperature can be even stronger than their counterparts sintered at high temperatures (typically ≈ 2/3 T m). Hydrothermal Hot Pressing (HHP) was originally conceived in the context of sustainability and environmental preservation, with some examples being the concept of 'synthetic rock' for immobilisation of toxic/radioactive waste and the consolidation of high surface area porous ceramics for filtration. Follow up work on HHP considered the possibility of recreating in the lab bio-mineralisation using hydroxyapatite and bioglass (including hybrids) as proof of concept. Recent work on the Cold Sintering Process has demonstrated the potential to bridge the processing gap of multimaterial devices (sensors, batteries, 5G antennas, electronic components and biomaterials), enabling integration of polymers, ceramics and metals without degradation of the individual components both at the bulk and interface level. The absence of heating unlocks grain boundary design to an unprecedented level, offering further degrees of freedom in tuning functional properties. This review provides a wide perspective on room temperature consolidation, and covers the related but fragmented work published (≈ 450 papers) during the past 50 years, encompassing the relevant work developed in different disciplines including chemistry, physics, biology and geoscience. Liquid-assisted or liquid-mediated phenomena involving diffusion, plasticity, rheology, and grain growth are still largely unexplored in material science. The purpose of bringing together this literature is to build a general and multidisciplinary knowledge to guide future research directions. Both the reduction of energy consumption and carbon footprint are driving the growing interest in ULES, which could reinvent the concept of sintering, 'rendering kilns obsolete'. Also, ULES has the potential to produce new classes of materials that cannot be fabricated using conventional routes.

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“…Low temperature co-fired ceramics (LTCC) applications include wireless telecommunication, electronic warfare, satellite broadcasting, and intelligent transport systems (Ziolkowski 2003;Parke et al 2015;Sebastian, Wang, and Jantunen 2016;Zhang, Whittow, and Vardaxoglou 2017;Wang et al 2018;Zhou et al 2019;Faouri et al 2019). The growth of the mobile phone market in the 1990s led to extensive research and development in temperature stable, medium permittivity dielectric ceramics with applications such as resonators in filters for microwave (MW) communications.…”

Section: Introductionmentioning

confidence: 99%

Multi-material additive manufacturing of low sintering temperature Bi₂Mo₂O₉ceramics with Ag floating electrodes by selective laser burnout

Gheisari

Chamberlain

Chi-Tangyie

et al. 2020

Virtual and Physical Prototyping

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Additive manufacturing (AM) of co-fired low temperature ceramics offers a unique route for fabrication of novel 3D radio frequency (RF) and microwave communication components, embedded electronics and sensors. This paper describes the first-ever direct 3D printing of low temperature co-fired ceramics/floating electrode 3D structures. Slurry-based AM and selective laser burnout (SLB) were used to fabricate bulk dielectric, Bi 2 Mo 2 O 9 (BMO, sintering temperature = 620-650°C, ε r = 38) with silver (Ag) internal floating electrodes. A printable BMO slurry was developed and the SLB optimised to improve edge definition and burn out the binder without damaging the ceramic. The SLB increased the green strength needed for shape retention, produced crack-free parts and prevented Ag leaching into the ceramic during co-firing. The green parts were sintered after SLB in a conventional furnace at 645°C for 4 h and achieved 94.5% density, compressive strength of 4097 MPa, a relative permittivity (ε r) of 33.8 and a loss tangent (tan δ) of 0.0004 (8 GHz) for BMO. The feasibility of using SLB followed by a postprinting sintering step to create BMO/Ag 3D structures was thus demonstrated.

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High quality factor cold sintered Li2MoO4BaFe12O19 composites for microwave applications

Cited by 62 publications

References 30 publications

Thermosetting polymers in cold sintering: The fabrication of ZnO‐polydimethylsiloxane composites

Thermosetting polymers in cold sintering: The fabrication of ZnO‐polydimethylsiloxane composites

A review of cold sintering processes

Multi-material additive manufacturing of low sintering temperature Bi₂Mo₂O₉ceramics with Ag floating electrodes by selective laser burnout

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High quality factor cold sintered Li2MoO4BaFe12O19 composites for microwave applications

Cited by 62 publications

References 30 publications

Thermosetting polymers in cold sintering: The fabrication of ZnO‐polydimethylsiloxane composites

Thermosetting polymers in cold sintering: The fabrication of ZnO‐polydimethylsiloxane composites

A review of cold sintering processes

Multi-material additive manufacturing of low sintering temperature Bi2Mo2O9ceramics with Ag floating electrodes by selective laser burnout

Contact Info

Product

Resources

About

Multi-material additive manufacturing of low sintering temperature Bi₂Mo₂O₉ceramics with Ag floating electrodes by selective laser burnout