Ceramic-based Composites Research Articles

Application of Metal-based, Polymer-based and Ceramic-Based Composites in Thermal Engine

Abstract. As a matter of fact, thermal engines have been widely implemented in various fields especially in recent years. In reality, the operation of the thermal engine produces numerous uncontrollable factors, which have a negative impact on the thermal engine machinery itself and negatively feedback the output effect of the thermal engine. Among various factors, the composites of coatings have a huge impact on the performances for the thermal engines. With this in mind, by analyzing various types of coatings in recent years and understanding the application of some coatings in other fields, this study will compare 3 typical types coting material, i.e., metal-based, polymer-based as well as ceramic-based composites. According to the analysis, Lenovo conceives whether it has suitable performance and function on the thermal machine. Introduce the feasibility of composite materials, and comprehensively analyze the specificity of various coatings. On the basis of effective implementation technology, the composite is envisaged.

Analysis of Polymer-Ceramic Composites Performance on Electrical and Mechanical Properties through Finite Element and Empirical Models.

Polymer and ceramic-based composites offer a unique blend of desirable traits for improving dielectric permittivity. This study employs an empirical approach to estimate the dielectric permittivity of composite materials and uses a finite element model to understand the effects of permittivity and filler concentration on mechanical and electrical properties. The empirical model combines the Maxwell-Wagner-Sillars (MWS) and Bruggeman models to estimate the effective permittivity using Barium Titanate (BT) and Calcium Copper Titanate Oxide (CCTO) as ceramic fillers dispersed in a Polydimethylsiloxane (PDMS) polymer matrix. Results indicate that the permittivity of the composite improves with increased filler content, with CCTO/PDMS emerging as the superior combination for capacitive applications. Capacitance and energy storage in the CCTO/PDMS composite material reached 900 nF and 450 nJ, respectively, with increased filler content. Additionally, increased pressure on the capacitive model with varied filler content showed promising effects on mechanical properties. The interaction between BT filler and the polymer matrix significantly altered the electrical properties of the model, primarily depending on the composite's permittivity. This study provides comprehensive insights into the effects of varied filler concentrations on estimating mechanical and electrical properties, aiding in the development of real-world pressure-based capacitive models.

Reinforcement mechanisms and current research status of silicon carbide whisker-reinforced composites: A comprehensive review

Abstract In recent decades, with the advancement of micro-electro-mechanical systems technology, traditional materials have become insufficient to meet the demands of cutting-edge technology for various material properties. Composites have attracted widespread attention as an effective and viable solution. Silicon carbide whiskers (SiCw) have emerged as excellent reinforcements due to their high thermal conductivity, low thermal expansion coefficient, high melting point, superior mechanical properties, and high chemical stability. This article provides a comprehensive review of the reinforcement mechanisms and current research state of SiCw-reinforced composites. The reinforcement mechanisms include mainly grain refinement, load transfer, and crack bridging. The composites are categorized based on the type of the matrix: ceramic-based, metal-based, and polymer-based composites. The influence and parameter performance of the reinforcement mechanism on SiCw-reinforced composite materials with different matrices vary. However, the key to improving SiCw-reinforced composites lies in understanding the interplay of properties between the matrix and the reinforcement, as well as the ordered and regular distribution and binding at the interface. Finally, the current state and limitations of SiCw-reinforced composites are summarized, and future development trends are discussed. This article represents a great contribution to the future applications of SiCw-reinforced composite materials.

Tuning metastable austenite in a phase-transforming ceramic via matrix constraint

Martensitic phase-transforming ceramics can undergo reversible phase transformations under thermo-mechanical stimuli, yet brittle in their monolithic, polycrystalline form. Incorporating these ceramics into matrices thereby metastabilizing austenite gives rise to a significant toughening effect by triggering martensitic transformation. However, it remains a challenge to stabilize the austenite if the matrix is a light metal, because of its low strength, low melting temperature and high-chemical reactivity. In this study, we constructed a phase-transforming ceramic-metal (zirconia-aluminum) composite with tunable metastable austenite fractions via matrix constraint. Systematic experiments combined with thermodynamic and kinetic models uncover the effect of the matrix constraint and doping concentration on austenitization. By varying the processing parameters, we realized extensive tunability in metastable austenite content (0–100 wt.%) under different cerium doping concentrations (6–12 mol.%) in a wide range of processing temperatures (350–550°C). Our findings reveal the underlying mechanisms for promoting, stabilizing and fine-manipulating austenitization in martensitic phase-transforming ceramics under geometrical constraint, and may lay out the foundation for more extensive studies and applications of these phase-transforming ceramic-based composites.

In-plane shear failure behavior and mechanical properties of SiC/SiC Composites

Fiber-reinforced ceramic matrix composites, especially SiC/SiC composites, have the characteristics of lightweight, high strength, high-temperature resistance, etc., which are ideal structural candidates for aerospace vehicle components, in-plane shear performance is one of the important indicators to characterize the mechanical properties of materials and component assessment, this paper designs and processes the in-plane shear test pieces and test devices and methods to study the shear mechanical behavior under the mechanical properties and failure behavior of SiC/SiC ceramic-based fiber bundle composites are studied under shear mechanical behavior. The results show that matrix cracking and fiber fracture are the main failure modes, and there are two obvious phases in the specimen shear force-displacement curves, and fiber fracture is the main cause of strain in the specimen.

Tribological Properties of Blocky Composites with Carbon Nanotubes.

A large amount of primary energy is lost due to friction, and the study of new additive materials to improve friction performance is in line with the concept of low carbon. Carbon nanotubes (CNTs) have advantages in drag reduction and wear resistance with their hollow structure and self-lubricating properties. This review investigated the mechanism of improving friction properties of blocky composites (including polymer, metal, and ceramic-based composites) with CNTs' incorporation. The characteristic tubular structure and the carbon film make low wear rate and friction coefficient on the surface. In addition, the effect of CNTs' aggregation and interfacial bond strength on the wear resistance was analyzed. Within an appropriate concentration range of CNTs, the blocky composites exhibit better wear resistance properties. Based on the differences in drag reduction and wear resistance in different materials and preparation methods, further research directions of CNTs have been suggested.

Fabrication of cemented carbides with bidirectional gradient structure via graphene deposition to simultaneously enhance surface hardness and toughness

The adoption of a continuous gradient in Co content stands as the foremost strategy for attaining heightened surface hardness and improved core toughness in cemented carbides. Nevertheless, the reduction in surface toughness stemming from a decreased Co content often precipitates premature surface failure of components. In this paper, WC-11Co powders was utilized as the precursor materials for fabricating a bidirectional gradient cemented carbide using the combined approach of low-temperature presintering and ultrasonic treatment techniques. The resultant cemented carbide exhibited a distinct gradient distribution, characterized by a forward gradient of graphene content, a reverse gradient of Co content, a forward gradient of WC grain size, and a forward gradient of residual compressive stress. The hardening and toughening mechanisms of the fabricated bidirectional gradient cemented carbides were comprehensively characterized and quantitatively discussed. The results provide compelling evidence that the gradient distribution of Co content plays a crucial role in attaining an impressive surface hardness of 1820 kgf/mm2. By utilizing the crack bridging mechanism of graphene, which efficiently exploits its strain transfer capabilities across a semi-coherent interface, in conjunction with the toughening effects of crack deflection and residual compressive stress, an exceptional surface fracture toughness of 17.62 MPa m1/2 is achieved. Additionally, the gradient layer exhibited a higher critical load for cracking. The present findings presents a novel strategy for the fabrication of high-performance ceramic-based composites.

Synthesis and Characterization of High-Purity, High-Entropy Diboride Ceramic Powders by a Liquid Phase Method

A nano-dual-phase powder with ultra-fine grain size was synthesized by the liquid precursor method at 1200 °C. A series of single-phase high-entropy ceramic powders ((Ti, Zr, Hf, Nb)B2, (Ti, Zr, Hf, Nb, Ta)B2, (Ti, Zr, Hf, Nb, Mo)B2, (Ti, Zr, Hf, Nb, Ta, Mo)B2) with high purity (C content less than 0.9 wt% and O content less than 0.7 wt%) and ultrafine (average grain sizes of 340–570 nm) were successfully synthesized at 1800 °C. The sample of (TiZrHfNbTa)B2 exhibited a hexagonal close-packed (HCP) structure, and the metal elements were uniformly distributed at the nanoscale, microscale, and macroscale. This method did not apply to the preparation of all high-entropy ceramic powders and was unfavorable for the formation of single-phase high-entropy borides when the size difference factor exceeded 3.9%. The present work provides a guide for the development of ceramic-based composites through precursor impregnation pyrolysis.

Progress in Polymer-based Composites as Efficient Materials for Electromagnetic Interference Shielding Applications: A Review

: Different electromagnetic interference (EMI) shielding materials have been developed over time. In the past electromagnetic (EM) shielding technology made use of metals and their composites because of good shielding effectiveness but their low elasticity high density and corrosion tendency render them obsolete. Ceramic-based composites have also gained popularity for EMI shielding applications because of their low density and excellent corrosion resistance but high absorption loss is a major drawback. Recently, polymer-based composites have attracted attention because they make for superb EMI shielding with the advantages of electromagnetic wave absorption over reflection and have been widely used with fast growth in application after their emergence. This paper reviews the progress of polymer-based composites as efficient materials for electromagnetic interference shielding and applications. : Electromagnetic (EM) waves are formed by the interaction of an electric field and a magnetic field. EM waves require no specific medium through which they can move. Their movement can be though air solid materials liquid or even vacuum. The EM spectrum ranges from lower energy waves (longer wavelengths) such as radio waves and microwaves to higher energy waves (shorter wavelengths), such as gamma rays and X-rays. Traditional materials such as metals and ceramics were found to be useful as EMI shielding materials. However, low elasticity high density and high absorption loss tend to limit their EMI effectiveness. Recently polymer-based electromagnetic shielding materials have been widely employed as EMI shielding materials. Given the above different EMI shielding materials based on diverse matrix materials are discussed with emphasis on polymer-based composites as emerging and alternative EMI shielding materials. : The development of the electronic industry offers weight reduction as an additional technical requirement besides good EMI shielding performance. EMI shielding ensures the inhibition of the transmission of EM waves from one point to another using shield materials. Metals as conventional EMI shielding materials have been substituted with alternative materials which are lighter such as polymer-based materials and ceramic-based materials.

Ceramics matrix composites for biomedical applications - a review

Composite materials have found varying applications in biomedical engineering. With their different physical, chemical, and mechanical properties, composites are produced to meet specific requirements for specific purposes. Synthetic materials are utilized in construction, such as automotive, buildings, mobile sector as well as bridges, aeronautics, naval (e.g., ships and boats), and biomedical sciences. Despite the fact that metallic, polymeric, and ceramic biomaterials have been used in medical facilities for decades for treatments including tissue repair and replacement, bone fixation, dental implants, and many others, composites are only now becoming widely known for orthopedic applications, a new generation of biocompatible, bioactive, as well as biodegradable metallic materials has recently been created. These ceramic materials are known for their strength and biocompatibility. Magnesium in its pure form, its alloys, and alloy-based composites are frequently employed in biomedical applications due to their high biocompatibility and moderate strength. This comprehensive research focuses on the mechanical (strength base) characteristics and corrosion resistance of several classes of biodegradable magnesium matrix composites. It also reviews the use of ceramic-based composites for biomedical applications. It concludes with the submission that ceramics-based composites are a welcomed mainstay in the biomedical world as a viable material. It is believed that this review will draw the attention of personnel to the gains of the adoption of ceramic matrix composites to biomedical applications.

Overview of Electric Discharge Machining of MachineTooled Ceramics and Ceramic-Based Composites

Accordingly, many engineering designers have improved the wear friction performance of such materials. Also, the use of polymers as reinforcements in their endeavors has been done to improve intrinsic performance. Intrinsic properties played an important role in intrinsic polymer orientations, improving the cohesion of some reinforcement while at the same time worsening those Effects Woven glass, carbon and amethyst polymeric composites Inter-laminar shear strength and abrasion composites samples. Wear properties are calculated using machine and testing machine in computer aided universal testing. Fracture of composites showed surface modifications for Group bonding. The mechanical properties of basalt are better than glass reinforced composites the result of the study confirms the applicability of basalt as a reinforcing agent in polymer composites. Hybrid Mechanical Processes Ultrasonic assisted laser/water jet machining processes are used to solve machining problems related to insulating ceramics such as ultrasonic assisted discharge machining, discharge milling, electro-chemical discharge machining and powder hybrid discharge machining and discharge diamond grinding. Processes can create complex patterns in spark discharges. An attempt has been made here to compare the convex stability with the above cast iron and polymer impregnated mechanical properties.

Spark Plasma Sintering of Complex Metal and Ceramic Structures Produced by Material Extrusion.

Alternative approaches to laser fusion for the additive manufacturing (AM) of metals are often hampered by the need for long sintering cycles. Typical sintering cycles require heating at temperatures above 80% of the melting point for several hours. The process is time- and energy-consuming, particularly when high-melting materials are involved. Applying pressure can drastically reduce the time and temperature required for densification. Recently, a particular kind of pressure-assisted sintering process known as spark plasma sintering (SPS) or field-assisted sintering (FAST) received considerable attention in academia and industry due to its ability to enhance densification. However, conventional SPS/FAST techniques cannot be directly applied to the densification of objects presenting a complex geometry. This work shows how a modified SPS/FAST setup, operating in a pseudoisostatic mode, can be used for debinding and sinter objects produced by material extrusion. This approach can be applied to metals and metal-based and ceramic-based composites when their geometry does not include closed cavities. Depending on the characteristics of the pressure-transfer medium, some level of anisotropy in the volume reduction associated with the densification can be observed. Still, it can easily be corrected by appropriately compensating sintering deformation during printing. Using this approach, the time required for the debinding and sintering can be reduced considerably. It represents an alternative approach to the AM of a wide range of inorganic materials characterized by a relatively low-cost, high material flexibility, and low environmental impact.

Toughening Ceramic-Based Composites by Homogenizing the Lattice Strain at Phase Boundaries.

Ceramic-based composites generally have low fracture toughness, and toughening these materials without sacrificing their hardness has been a big challenge. This study presents an approach for toughening ceramic-based composites by modulating the strain partition and stress distribution in phase-boundary regions. A new concept of homogenizing the lattice strain to achieve high fracture toughness in ceramic-based composites is proposed based on the collective lattice shear of martensitic phase transformation. The strategy was demonstrated by ZrO2-containing WC-Co ceramic-metal composites as a prototype. The crystal planes along the WC/ZrO2 martensitic transforming phase boundaries exhibited significantly larger and uniform lattice strains compared with conventional dislocation pile-up phase boundaries with highly localized lattice strains. The homogeneous strain and stress distributions across interfaces enabled the composite to have simultaneously high fracture toughness and hardness. The "homogenizing the lattice strain" strategy proposed in this work is applicable to a broad range of ceramic-based composites to achieve superior comprehensive mechanical properties.

A Review of Additive Manufacturing Processes for Fabricating Ceramics and Composites

Abstract This article reviews additive manufacturing technologies that can be used for manufacturing ceramics and ceramic-based composites. Stereolithography and associated techniques offer the possibility of producing ceramic components with finer resolution. Powder-based techniques like binder jetting and indirect selective laser sintering can be used for designing porous ceramics. Selective laser melting offers practitioners the option of manufacturing ceramics with minimal post-processing requirements, although further research is needed to decrease its cost.

Simultaneous enhancement of mechanical and ablation properties of C/C composites modified by (Hf-Ta-Zr)C solid solution ceramics

In order to improve the mechanical and ablative resistance of C/C composites, (Hf-Ta-Zr)C single-phase solid solution ceramics were introduced into C/C composites by polymer infiltration and pyrolysis (PIP) to fabricate (Hf-Ta-Zr)C modified C/C composites (HTZ). Their mechanical property and ablation resistance were studied. The results showed that HTZ achieved simultaneous enhancement of mechanical property and ablative resistance. Their flexural strength and modulus could reach 219.34 MPa and 24.82 GPa, respectively. In addition, the mass and linear ablation rate of HTZ were 0.379 mg/s and 0.667 µm/s, respectively after the 90 s oxyacetylene ablation. A dense Hf-Ta-Zr-O multiphase oxide layer was formed on the surface of the HTZ during ablation process, which protected the interior modified C/C composites from ablation. Our work expands a rational design of modified C/C composites and broaden the application of solid solution ceramic in the field of ultra-high temperature ablation resistance for carbon or ceramic-based composites.

Additively manufactured Bi-functionalized bioceramics for reconstruction of bone tumor defects.

Bone tissue exhibits critical factors for metastatic cancer cells and represents an extremely pleasant spot for further growth of tumors. The number of metastatic bone lesions and primary tumors that arise directly from cells comprised in the bone milieu is constantly increasing. Bioceramics have recently received significant attention in bone tissue engineering and local drug delivery applications. Additionally, additive manufacturing of bioceramics offers unprecedented advantages including the possibilities to fill irregular voids after the resection and fabricate patient-specific implants. Herein, we investigated the recent advances in additively manufactured bioceramics and ceramic-based composites that were used in the local bone tumor treatment and reconstruction of bone tumor defects. Furthermore, it has been extensively explained how to bi-functionalize ceramics-based biomaterials and what current limitations impede their clinical application. We have also discussed the importance of further development into ceramic-based biomaterials and molecular biology of bone tumors to: (1) discover new potential therapeutic targets to enhance conventional therapies, (2) local delivering of bio-molecular agents in a customized and "smart" way, and (3) accomplish a complete elimination of tumor cells in order to prevent tumor recurrence formation. We emphasized that by developing the research focus on the introduction of novel 3D-printed bioceramics with unique properties such as stimuli responsiveness, it will be possible to fabricate smart bioceramics that promote bone regeneration while minimizing the side-effects and effectively eradicate bone tumors while promoting bone regeneration. In fact, by combining all these therapeutic strategies and additive manufacturing, it is likely to provide personalized tumor-targeting therapies for cancer patients in the foreseeable future. STATEMENT OF SIGNIFICANCE: To increase the survival rates of cancer patients, different strategies such as surgery, reconstruction, chemotherapy, radiotherapy, etc have proven to be essential. Nonetheless, these therapeutic protocols have reached a plateau in their effectiveness due to limitations including drug resistance, tumor recurrence after surgery, toxic side-effects, and impaired bone regeneration following tumor resection. Hence, novel approaches to specifically and locally attack cancer cells, while also regenerating the damaged bony tissue, have being developed in the past years. This review sheds light to the novel approaches that enhance local bone tumor therapy and reconstruction procedures by combining additive manufacturing of ceramic biomaterials and other polymers, bioactive molecules, nanoparticles to affect bone tumor functions, metabolism, and microenvironment.

Scientific Advancements in Composite Materials for Aircraft Applications: A Review.

Recent advances in aircraft materials and their manufacturing technologies have enabled progressive growth in innovative materials such as composites. Al-based, Mg-based, Ti-based alloys, ceramic-based, and polymer-based composites have been developed for the aerospace industry with outstanding properties. However, these materials still have some limitations such as insufficient mechanical properties, stress corrosion cracking, fretting wear, and corrosion. Subsequently, extensive studies have been conducted to develop aerospace materials that possess superior mechanical performance and are corrosion-resistant. Such materials can improve the performance as well as the life cycle cost. This review introduces the recent advancements in the development of composites for aircraft applications. Then it focuses on the studies conducted on composite materials developed for aircraft structures, followed by various fabrication techniques and then their applications in the aircraft industry. Finally, it summarizes the efforts made by the researchers so far and the challenges faced by them, followed by the future trends in aircraft materials.

Stress-Induced Microcracking and Fracture Characterization for Ultra-High-Temperature Ceramic Matrix Composites at High Temperatures.

In this paper, we estimated the temperature-dependent critical inclusion size for microcracking under residual stress and applied stress for particulate-reinforced ultra-high-temperature ceramic matrix composites. The critical flaw size and applied stress for the stable growth of radial cracks under different temperatures were also estimated. It was found that under a lower applied stress, the critical inclusion size was sensitive to the temperature. Under higher applied stresses, the sensitivity became smaller. For ceramic materials with pre-existing microcracks, the crack resistance could be improved by increasing the service stress when the service stress was low. As the temperature increased, the critical flaw size of the materials decreased; the applied stress first increased and then decreased. Finally, a temperature-dependent fracture strength model of composites with a pre-existing critical flaw was proposed. A good agreement was obtained between the model prediction and the experimental data. In this work, we show a method for the characterization of the effects of temperature on the fracture behavior of ceramic-based composites.

Highly efficient preparation of multi-angle continuous carbon fibre reinforced hydroxyapatite composites by electrostatic splitting method

An electrostatic splitting device was self-designed and manufactured for highly efficient preparation of multi-angle continuous carbon fibre (CF)-reinforced ceramic-based composites and was used to prepare multi-angle continuous CF and nano-hydroxyapatite (nHA)-coated CF reinforced HA composites with improved CF dispersion and content. The compressive strength of sintered [0°/90°] CF reinforced hydroxyapatite (CF/HA) composites is more than two and a half times that of hydroxyapatite and is superior to that of cortical bone (26.42–110.7%). Compared with hydroxyapatite, fracture toughness of [0°/0°], [0°/90°] and [− 45°/+ 45°] CF/HA composites increase by 28.83%, 66.32% and 115.95%, respectively. The strength and fracture toughness (30.2 MPa·m1/2) of [− 45°/+ 45°] CF/HA bioceramics display synchronously improving. Micromechanical property and crack propagation process of the composites were simulated in depth. Based on optimised dispersion and arrangement of CF, the introduction of nHA coating enhances the mechanical properties of nHA-coated CF reinforced HA composites because nHA coating can block the generation and propagation of cracks.

Toughening mechanisms in nacre-like alumina revealed by in-situ imaging of stress

Nacre-like aluminas are bio-inspired, ceramic-based composites that display high toughness and strength. Their toughness arises from their brick-and-mortar microstructure. We must understand the role of several microstructural features over their mechanical properties. Techniques that allow microstructural imaging during mechanical tests are therefore desired. Here, we use both in situ fluorescence spectroscopy to image the stress field around cracks propagating in samples, and in situ scanning electron microscopy to image the crack-microstructure interactions. Stress concentrates around locally disordered zones where the crack is pinned while crack propagation is delayed. In situ imaging shows that obstacles to crack propagation are either larger-than-average alumina platelets or bundles of alumina platelets misaligned with respect to the majority of the platelets. Such microstructural heterogeneities are therefore important to impede crack propagation in nacre-like alumina. The approach proposed here can be used to understand the structure/properties relationships of other types of materials.