Showing papers on "Ceramic published in 2021"

Chemical Processing of Ceramics

Abstract: Powder Synthesis and Characterization Hydrothermal Synthesis of Ceramic Oxide Powders, S. Somiya, R. Roy, and S. Komarneni Solvothermal Synthesis, M. Inoue Mechanochemical Synthesis of Ceramics, A.C. Dodd Cryochemical Synthesis of Materials, O.A. Shlyakhtin, N.N. Oleynikov, and Y.D. Tretyakov Environmentally Benign Approach to Synthesis of Titanium-Based Oxides by Use of Water-Soluble Titanium Complex, K. Tomita, D. Dey, V. Petrykin, and M. Kakihana Peroxoniobium-Mediated Route toward the Low-Temperature Synthesis of Alkali Metal Niobates Free from Organics and Chlorides, D. Dey and M. Kakihana Synthesis and Modification of Submicron Barium Titanate Powders, B.I. Lee, M. Wang, D.H. Yoon, P. Badheka, L. Qi, and L.-Q. Wang Magnetic Particles: Synthesis and Characterization, M. Ozaki Synthesis and Surface Modification of Zinc Sulfide-Based Phosphors, L. Qi, B.I. Lee, D. Morton, and E. Forsythe Characterization of Fine Dry Powders, H.K. Kammler and L. Madler Powder Processing at Nanoscale Theory and Applications of Colloidal Processing, W. Sigmund, G. Pyrgiotakis, and A. Daga Nanomicrostructure and Property Control of Single and Multiphase Materials, P. Colomban Nanocomposite Materials, S. Komarneni Molecular Engineering Route to Two Dimensional Heterostructural Nanohybrid Materials, J.-H. Choy and M. Park Nanoceramic Particulates for Chemical Mechanical Planarization in the Ultra Large Scale Integration Fabrication Process, U. Paik, S.K. Kim, T. Katoh, and J.G. Park Sol-Gel Processing Chemical Control of Defect Formation During Spin-Coating of Sol-Gels, D.P. Birnie, III Preparation and Properties of SiO2 Thin Films by the Sol-Gel Method Using Photoirradiation and Its Application to Surface Coating for Display, T. Ohishi Ceramic Via Polymers Organosilicon Polymers as Precursors for Ceramics, M. Weinmann Polymer Pyrolysis, M. Narisawa Processing of Specialty Ceramics Chemical Vapor Deposition of Ceramics, G. Cao and Y. Wang Ceramic Photonic Crystals: Materials, Synthesis, and Applications, J. DiMaio and J. Ballato Tailoring Dielectric Properties of Perovskite Ceramics at Microwave Frequencies, E.S. Kim, K.H. Yoon, and B.I. Lee Synthesis and Processing of High-Temperature Superconductors, T. Doi Synthesis of Bone-Like Hydroxyapatite/Collagen Self-Organized Nanocomposites in Chemical Processing of Ceramics, M. Kikuchi Ceramic Membrane Processing: New Approaches in Design and Applications, A. Ayral, A. Julbe, and C. Guizard Ceramic Materials for Lithium-Ion Battery Applications, J.P. Maranchi, O.I. Velikokhatnyi, M.K. Datta, I.-S. Kim, and P.N. Kumta Chemical Solution Deposition of Ferroelectric Thin Films, R. Schwartz, T. Schneller, R. Waser, and H. Dobberstein Index

Recent advances in layered Ln2NiO4+δ nickelates: fundamentals and prospects of their applications in protonic ceramic fuel and electrolysis cells

Abstract: In the past decade, intensive research on proton-conducting oxide materials has provided a basis for the development of intermediate-temperature protonic ceramic electrochemical cells, which constitute a real alternative to conventional cells based on oxygen-conducting electrolytes. To achieve both high efficiency and excellent performance, not only electrolytes but also electrode materials should be carefully selected considering their functional properties. Compared to the traditional ABO3 perovskite electrode materials, Ln2NiO4+δ with a layered structure has unique advantages (high chemical stability, mechanical compatibility, improved oxygen transport, and hydration ability), and thus is now becoming a hot topic in this field, offering both scientific and practical interests. However, a comprehensive and in-depth review is still lacking in the literature to date. Accordingly, this work presents a comprehensive overview of the prospects of layered nickelates (Ln2NiO4+δ, where Ln = La, Nd, and Pr) as one of the most attractive oxygen (steam) electrode materials for protonic ceramic electrochemical cells. In particular, the crystalline features, defect structure, stability, chemical properties, and mechanical compatibility of this class of materials, contributing to their transport functionality, are discussed with the primary emphasis on revealing the relationship between the composition of the materials and their properties. The presented systematic results reveal the main strategies regarding the utilisation of Ln2NiO4+δ-based electrodes and existing gaps related to fundamental and applied research aspects.

Progress and perspectives in dielectric energy storage ceramics

Abstract: Dielectric ceramic capacitors, with the advantages of high power density, fast charge-discharge capability, excellent fatigue endurance, and good high temperature stability, have been acknowledged to be promising candidates for solid-state pulse power systems. This review investigates the energy storage performances of linear dielectric, relaxor ferroelectric, and antiferroelectric from the viewpoint of chemical modification, macro/microstructural design, and electrical property optimization. Research progress of ceramic bulks and films for Pb-based and/or Pb-free systems is summarized. Finally, we propose the perspectives on the development of energy storage ceramics for pulse power capacitors in the future.

Interface formation and bonding control in high-volume-fraction (TiC+TiB2)/Al composites and their roles in enhancing properties

Abstract: As interfaces play a more important role in high-volume-fraction ceramic/metal composites because of containing more hetero-phase interfaces, it is a great challenge to control the interfaces in such composites to balance their strength and plasticity and to obtain high performances. In this work, 50–60 vol% (TiC + TiB2)/Al composites were fabricated in Al–Ti–B4C system via a one-step method of reaction and densification, and their interface bonding and mechanical properties were compared with those of in-situ TiC/Al composites. Apparently, the defects, such as interfacial discontinuity, macro-pores, coarsening and agglomeration of particles, caused by increased ceramic content in the TiC/Al composites, are eliminated in the (TiC + TiB2)/Al composites using Al–Ti–B4C system. The 60 vol% (TiC + TiB2)/Al composite exhibits significantly enhanced mechanical properties, i.e. 70.5%, 60.7% and 69.8% respectively higher yield strength, ultimate compressive strength and plastic strain than 60 vol% TiC/Al composite. Such enhanced mechanical properties are attributed to the improvement in interface bonding strength and therefore the increase in the energy dissipation of crack propagation. The formation of enhanced interface in the (TiC + TiB2)/Al composites results from the reduction in the reaction heat in the Al–Ti–B4C system, improved crystallographic match and improved adhesion work between ceramic particles and matrix. This work may provide a new idea for the design and control of interfaces in high-volume-fraction ceramic-metal composites.

Photopolymerization-based additive manufacturing of ceramics: A systematic review

Abstract: Conversion of inorganic-organic frameworks (ceramic precursors and ceramic-polymer mixtures) into solid mass ceramic structures based on photopolymerization process is currently receiving plentiful attention in the field of additive manufacturing (3D printing). Various techniques (e.g., stereolithography, digital light processing, and two-photon polymerization) that are compatible with this strategy have so far been widely investigated. This is due to their cost-viability, flexibility, and ability to design and manufacture complex geometric structures. Different platforms related to these techniques have been developed too, in order to meet up with modern technology demand. Most relevant to this review are the challenges faced by the researchers in using these 3D printing techniques for the fabrication of ceramic structures. These challenges often range from shape shrinkage, mass loss, poor densification, cracking, weak mechanical performance to undesirable surface roughness of the final ceramic structures. This is due to the brittle nature of ceramic materials. Based on the summary and discussion on the current progress of material-technique correlation available, here we show the significance of material composition and printing processes in addressing these challenges. The use of appropriate solid loading, solvent, and preceramic polymers in forming slurries is suggested as steps in the right direction. Techniques are indicated as another factor playing vital roles and their selection and development are suggested as plausible ways to remove these barriers.

Bridging Interparticle Li + Conduction in a Soft Ceramic Oxide Electrolyte

Abstract: Li+-conductive ceramic oxide electrolytes, such as garnet-structured Li7La3Zr2O12, have been considered as promising candidates for realizing the next-generation solid-state Li-metal batteries with high energy density. Practically, the ceramic pellets sintered at elevated temperatures are often provided with high stiffness yet low fracture toughness, making them too brittle for the manufacture of thin-film electrolytes and strain-involved operation of solid-state batteries. The ceramic powder, though provided with ductility, does not yield satisfactorily high Li+ conductivity due to poor ion conduction at the boundaries of ceramic particles. Here we show, with solid-state nuclear magnetic resonance, that a uniform conjugated polymer nanocoating formed on the surface of ceramic oxide particles builds pathways for Li+ conduction between adjacent particles in the unsintered ceramics. A tape-casted thin-film electrolyte (thickness: <10 μm), prepared from the polymer-coated ceramic particles, exhibits sufficient ionic conductivity, a high Li+ transference number, and a broad electrochemical window to enable stable cycling of symmetric Li/Li cells and all-solid-state rechargeable Li-metal cells.

Rheological characterisation of ceramic inks for 3D direct ink writing: A review

Abstract: 3D printing is a competitive manufacturing technology, which has opened up new possibilities for the fabrication of complex ceramic structures and customised parts. Extrusion-based technologies, also known as direct ink writing (DIW) or robocasting, are amongst the most used for ceramic materials. In them, the rheological properties of the ink play a crucial role, determining both the extrudability of the paste and the shape fidelity of the printed parts. However, comprehensive rheological studies of printable ceramic inks are scarce and may be difficult to understand for non-specialists. The aim of this review is to provide an overview of the main types of ceramic ink formulations developed for DIW and a detailed description of the more relevant rheological tests for assessing the printability of ceramic pastes. Moreover, the key rheological parameters are identified and linked to printability aspects, including the values reported in the literature for different ink compositions.

Progress and challenges towards additive manufacturing of SiC ceramic

Abstract: Silicon carbide (SiC) ceramic and related materials are widely used in various military and engineering fields. The emergence of additive manufacturing (AM) technologies provides a new approach for the fabrication of SiC ceramic products. This article systematically reviews the additive manufacturing technologies of SiC ceramic developed in recent years, including Indirect Additive Manufacturing (Indirect AM) and Direct Additive Manufacturing (Direct AM) technologies. This review also summarizes the key scientific and technological challenges for the additive manufacturing of SiC ceramic, and also forecasts its possible future opportunities. This paper aims to provide a helpful guidance for the additive manufacturing of SiC ceramic and other structural ceramics.

Direct ink writing (DIW) of structural and functional ceramics: Recent achievements and future challenges

Abstract: Along with vast research on the additive manufacturing (AM) of polymeric and metallic materials, three-dimensional (3D) manufacturing of ceramic materials is now the modern trend. Among all the additive manufacturing techniques, Direct Ink Writing (DIW) permits the ease of design and rapid manufacturing of ceramic-based materials in complicated geometries. This paper presents an outline of the contributions and tasks in the fabrication 3D ceramic parts by the DIW technique. The current state-of-the-art manufacturing of various ceramics such as alumina, zirconia, and their composites through Direct Ink Writing (DIW) is described in detail. Moreover, this review paper aims at the innovations in the DIW approach of ceramic materials and introduces the progression of the DIW for the manufacturing of ceramics. Most importantly, the DIW technique has been explained in detail with illustrations. The prospects and challenges related to the DIW technique are also underscored.

A low-firing melilite ceramic Ba2CuGe2O7 and compositional modulation on microwave dielectric properties through Mg substitution

Abstract: A melilite Ba2CuGe2O7 ceramic was characterized by low sintering temperature and moderate microwave dielectric properties. Sintered at 960 °C, the Ba2CuGe2O7 ceramic had a high relative density 97%, a low relative permittivity (er) 9.43, a quality factor (Q×f) of 20,000 GHz, and a temperature coefficient of resonance frequency (τf) −76 ppm/°C. To get a deep understanding of the relationship between composition, structure, and dielectric performances, magnesium substitution for copper in Ba2CuGe2O7 was conducted. Influences of magnesium doping on the sintering behavior, crystal structure, and microwave dielectric properties were studied. Mg doping in Ba2CuGe2O7 caused negligible changes in the macroscopic crystal structure, grain morphology, and size distribution, while induced visible variation in the local structure as revealed by Raman analysis. Microwave dielectric properties exhibit a remarkable dependence on composition. On increasing the magnesium content, the relative permittivity featured a continuous decrease, while both the quality factor and the temperature coefficient of resonance frequency increased monotonously. Such variations in dielectric performances were clarified in terms of the polarizability, packing fraction, and band valence theory.

Excellent energy storage properties and stability of NaNbO3–Bi(Mg0.5Ta0.5)O3 ceramics by introducing (Bi0.5Na0.5)0.7Sr0.3TiO3

Abstract: NaNbO3-based (NN) energy storage ceramics exhibit high breakdown electric field strength (Eb) with large recoverable energy storage density (Wrec). However, due to their large energy loss density (Wloss) under strong electric fields, maintaining high energy storage efficiency (η) is a challenge. In this study, to produce a dielectric ceramic with both high Wrec and η, a ternary system was designed. By the addition of (Bi0.5Na0.5)0.7Sr0.3TiO3 (BNST), the grain size of 0.90NaNbO3–0.10Bi(Mg0.5Ta0.5)O3 (0.10BMT) was effectively reduced, and the long-range ordered structure was broken, providing an easily turned over dielectric domain to inhibit Wloss. The activation energy of the grain boundary increased with the increase in resistivity, indicating that the concentration of free vacancies at the grain boundary was low. The jump barrier of oxygen vacancies in the grain boundary increased, making up for the grain boundary defects, thus increasing Eb. When the BNST concentration increased, the Eb and Wrec of the dielectric ceramics increased. Optimum performance was obtained with the 0.75[0.90NaNbO3–0.10Bi(Mg0.5Ta0.5)O3]–0.25(Bi0.5Na0.5)0.7Sr0.3TiO3 (0.25BNST) ceramic, which exhibited an exceptionally high Eb (800 kV cm−1) and Wrec (8 J cm−3), while maintaining a relatively high η (90.4%). The ceramics developed in this study showed excellent temperature and frequency stability over 20–200 °C and 1–160 Hz, respectively. In addition, the dielectric properties of the ceramics were maintained after 10 000 hysteresis cycles. The 0.25BNST ceramic showed an exceptionally fast t0.9 (∼32 ns) and a high CD (614.5A cm−2). This study demonstrates that the energy storage performance and stability of the fabricated 0.25BNST ceramic are superior to those of previously reported dielectric ceramics.

An Active and Robust Air Electrode for Reversible Protonic Ceramic Electrochemical Cells

Abstract: Reversible protonic ceramic electrochemical cells (R-PCECs) are a promising option for efficient and low-cost generation of electricity and hydrogen Commercialization of R-PCECs, however, hinges o

Lead-Free BiFeO3-BaTiO3 Ceramics with High Curie Temperature: Fine Compositional Tuning across the Phase Boundary for High Piezoelectric Charge and Strain Coefficients.

Abstract: BiFeO3-BaTiO3 is a promising high-temperature piezoelectric ceramic that possesses both good electromechanical properties and a Curie temperature (TC). Here, the piezoelectric charge constants (d33) and strain coefficients (d*33) of (1 - x)BiFeO3-xBaTiO3 (BF-xBT; 0.20 ≤ x ≤ 0.50) lead-free piezoelectrics were investigated at room temperature. The results showed a maximum d33 of 225 pC/N in the BF-0.30BT ceramic and a maximum d*33 of 405 pm/V in the BF-0.35BT ceramic, with TCs of 503 and 415 °C, respectively. To better understand the performance enhancement mechanisms, a phase diagram was established using the results of XRD, piezoresponse force microscopy, TEM, and electrical property measurements. The superb d33 of the BF-0.30BT ceramic arose because of its location in the optimum point in the morphotropic phase boundary, low oxygen vacancy (VO··) concentration, and domain heterogeneity. The superior d*33 of the BF-0.35BT ceramic was attributed to a weak relaxor behavior between coexisting macrodomains and polar nanoregions. The presented strategy provides guidelines for designing high-temperature BF-BT ceramics for different applications.

High Energy Density Solid State Lithium Metal Batteries Enabled by Sub-5 µm Solid Polymer Electrolytes.

Abstract: Solid-state batteries (SSBs) are considered as the most promising next-generation high-energy-density energy storage devices due to their ability in addressing the safety concerns from organic electrolytes and enabling energy dense lithium anodes. To ensure the high energy density of SSBs, solid-state electrolytes (SSEs) are required to be thin and light-weight, and simultaneously offer a wide electrochemical window to pair with high-voltage cathodes. However, the decrease of SSE thickness and delicate structure may increase the cell safety risks, which is detrimental for the practical application of SSBs. Herein, to demonstrate a high-energy-density SSB with sufficient safety insurance, an ultrathin (4.2 µm) bilayer SSE with porous ceramic scaffold and double-layer Li+ -conducting polymer, is proposed. The fire-resistant and stiff ceramic scaffold improves the safety capability and mechanical strength of the composite SSE, and the bilayer polymer structure enhances the compatibility of Li metal anode and high-voltage cathodes. The 3D ceramic facilitates Li-ion conduction and regulates Li deposition. Thus, high energy density of 506 Wh kg-1 and 1514 Wh L-1 is achieved based on LiNi0.8 Co0.1 Mn0.1 O2 (NCM811) cathodes with a low N/P ratio and long lifespan over 3000 h. High-energy-density anode-free cells are further demonstrated.