Metal-ceramic Composites Research Articles

Centrifugal directional freezing and pressure infiltration: Tailoring gradient structures and mechanical properties in Al/B4C composites

Inspired by the gradient structures found in natural materials like bone, this study presents a novel fabrication method combining centrifugal freeze casting and pressure infiltration to produce Al/B4C composites with a tunable gradient layered structure, effectively addressing the challenge of achieving both high strength and toughness in metal-matrix composites. By precisely controlling key parameters such as centrifugal speed, ceramic content, particle size distribution, and freezing temperature, we achieved a gradient transition from high hardness and strength in the outer layers to lower hardness and higher toughness in the inner layers, mimicking the performance characteristics of natural materials. Specifically, higher centrifugal speeds and multi-sized ceramic particles promoted a more pronounced gradient structure, with larger particles concentrating in the outer regions for enhanced strength. While increasing ceramic content improved overall strength, it also affected toughness, highlighting the need for optimization. Freezing temperature influenced the ice-crystal structure and interlayer ceramic bridging, impacting both the gradient and overall composite properties. The optimized composites exhibited a unique combination of low density, high strength, and exceptional fracture toughness, primarily attributed to strong interfacial bonding, effective crack deflection and metal bridging, and formation of an interpenetrating structure. This study provides a versatile, cost-effective and scalable pathway for fabricating bioinspired high-performance metal–ceramic composites.

A novel route to produce metal or ceramic parts in space: local debinding and sintering of powdered filaments

AbstractIn-space manufacturing of polymer feedstocks has already been shown using the widely investigated filament extrusion additive manufacturing (AM) technology. Yet, polymers are only a small piece of the puzzle, and there is a growing demand to locally source metal and ceramic parts. In this manuscript, we propose a cost-effective method for in-orbit manufacturing of metal and ceramic multi-material components using highly packed powdered filaments, which need to be shaped, debinded, and sintered in sequential steps. Traditional debinding and sintering of material extrusion (MEX) AM parts are known to be time-consuming and require complex post-processing, often involving toxic debinding agents. To overcome this, a low-intensity infrared diode laser and an induction heater are coupled to a hybrid MEX system to allow full processing in situ, within the same volume. The results show that the main binder matrix can be removed across the 3D volume of the part via laser ablation of the polymeric mass, even for multi-material metal–ceramic composites. The sintered geometries further densify efficiently within the bulk due to the high-energy concentration of the induction sintering treatment, providing short processing times. Debinding and sintering locally, in the same machine, offer a simple and effective way to produce space hardware in situ, avoiding the use of consumables or part transportation to bulky equipment.

Investigation of kinetic mechanisms of photocatalytic hydrogen generation from formic aside using metal-ceramic composites under visible-light irradiation

Processes of photocatalytic hydrogen generation from the formic acid water solution under vis-light irradiation with tantalum contained metal-ceramic silicon nitride-based composites were investigated depending on pH of the solution and hydrogen peroxide adding. These compounds were obtained by self-propagated high temperature (SHS) synthesis in the way of the ferrosilicoaluminum (FSA) and silicon-aluminum powders ignition in a nitrogen atmosphere with the tantalum addition. During the investigation it was found out that the reaction rate of the hydrogen production without hydrogen peroxide can be described within the Langmuir–Hinshelwood mechanism. There is the reaction mechanism changing simultaneously with a formic acid concentration increasing in the presence of H2O2. The most significant reaction rate of hydrogen production from HCOOH is observed with the Fe-contained composite synthesized from FSA in the solution system without H2O2 addition, the reaction turns of frequency (TOF) is 4.55 µmol/min.

Gradient composites Al2O3-Ni obtained via the CSC technique in a magnetic field - microstructure and mechanical properties

This article presents the formation of composite microstructures by combining two established concepts: centrifugal slip casting and the utilization of a magnetic field to control the distribution of magnetic particles. The integration of these methodologies offers the potential to create zones within the composite with distinct hardness values. The study introduces a novel method for fabricating ceramic-metal composites, with a key focus on determining the feasibility of manipulating the location of the metallic phase using a magnetic field. Through this innovative approach, the research aims to produce composite hollow cylinders with a gradient distribution of metallic particles. The relative density of the composites was 97 %. The hardness values for the samples range from 970 HV to 2700 HV, displaying variability based on the metallic phase content within the material. The compressive strength for Al2O3-Ni samples was equal to 128.92 MPa. The Al2O3 grains in zone III after the sintering process have an average size of 1.27 ± 0.68 µm. The Al2O3-Ni composites indicate a smaller heat capacity of the material compared to pure Al2O3 samples.

Finite element modeling of thermal residual stresses in functionally graded aluminum-matrix composites using X-ray micro-computed tomography

Metal-ceramic composites by their nature have thermal residual stresses at the micro-level, which can compromise the integrity of structural elements made from these materials. The evaluation of thermal residual stresses is therefore of continuing research interest both experimentally and by modeling. In this study, two functionally graded aluminum alloy matrix composites, AlSi12/Al2O3 and AlSi12/SiC, each consisting of three composite layers with a stepwise gradient of ceramic content (10, 20, 30 vol%), were produced by powder metallurgy. Thermal residual stresses in the AlSi12 matrix and the ceramic reinforcement of the ungraded and graded composites were measured by neutron diffraction. Based on the X-ray micro-computed tomography (micro-XCT) images of the actual microstructure, a series of finite element models were developed to simulate the thermal residual stresses in the AlSi12 matrix and the reinforcing ceramics Al2O3 and SiC. The accuracy of the numerical predictions is high for all cases considered, with a difference of less than 5 % from the neutron diffraction measurements. It is shown numerically and validated by neutron diffraction data that the average residual stresses in the graded AlSi12/Al2O3 and AlSi12/SiC composites are lower than in the corresponding ungraded composites, which may be advantageous for engineering applications.

A comprehensive review on the analysis of adhesion strength of cold spray deposits

Cold spray (CS) is a new kind of coating that has many potential uses, including functionalizing surfaces, doing localized repairs, and mass production. Its fast deposition rate and diverse feedstocks have led to its growing popularity as an additive manufacturing method, which has been driven by improvements in lateral resolution. CS materials have several uses in the transportation industry, and some of the most frequent ones include nickel super-alloys, titanium alloys, copper, aluminum and metal-ceramic composites. Nevertheless, the mechanical properties depend upon number of parameters involved during spraying process. Therefore, there is an immediate need for researchers and businesses to understand the various parameters affecting the adhesion strength of CS deposits. The current research presents an analysis of the adhesion behavior of coatings that have been deposited by CS methodology.

Elucidating the effect of whiskers on microstructural, mechanical and wear properties of ceramic-metal composites for sports venues applications

Ceramic whiskers reinforced composites are widely used in electrical, medical, and constructional applications due to their desirable strengths, hardness, and wear characteristics. In this study, to examine the wear and friction characteristics, the pressureless infiltrated Cu–SiC composites with different content of SiC whiskers were roll bonded to Al layer. According to SEM images, the SiC whiskers were distributed across the microstructure although they were aligned along rolling direction. Incorporation of SiC whiskers to Cu matrix led to rise of composites’ strengths, young moduli, and hardness values. The measured values of Al and Cu–SiC layers increased from 50 HV to 135 HV in Al/Cu–SiC (5 wt%) to 57 HV and 159 HV in Al/Cu–SiC (15 wt%). Ductile type of fracture along with dimples, delamination, and debonding of whiskers appeared on fracture surfaces. However, more debonding of SiC whiskers was observed as SiC content increased. Accordingly, mass loss decreased and less adhesive wear mechanism was observed. The mass loss decreased from 6.3 mg in Al/Cu–SiC (5 wt%) to 5.2 mg in Al/Cu–SiC (15 wt%).

Combustion synthesis of TiC- high entropy alloy CoCrFeNiMn composites from granular mixtures

The advantage of combustion synthesis is the ability to produce composites from powders in a single technological step, using the heat of an exothermic reaction, in a fast and energy-efficient manner. Ceramic-metal composites TiC–High-Entropy Alloy (HEA) CoCrFeNiMn were fabricated by combustion synthesis from granular mixtures. The content of the metal binder components varied from 10 to 30 wt% and the combustion velocity and temperature gradually decreased as the binder content increased. Scaling up synthesis requires clarification of the parametric range for implementing a safe combustion mode. The impurity gas content and the range of safe conductive combustion were determined from known theoretical models and experimental combustion velocities of samples of granules of 0.6 and 1.1 mm size. The main phases of the product were titanium carbide with up to 3 at. % Cr and HEA CrCoFeNiMn with a reduced Mn content compared to the equimolar composition. The content of secondary phases Cr7C3 and carbon did not exceed 5 wt%. The use of granular mixtures solved the problem of significant sintering of exothermic powder mixtures containing metal binder during combustion. After synthesis, the granules retain their size and do not sinter together, making it easy to grind the sample and obtain a TiC-HEA composite powder.

High Temperature Corrosion Resistant and Anti-slagging Coatings for Boilers: A Review

AbstractHigh temperature corrosion and slag deposition significantly reduce the thermal efficiency and lifespan of biomass-fired boilers. Surface modification with protective coatings can enhance boiler performance and prevent commercial losses due to maintenance and damage. This review focuses on the development of corrosion-resistant coatings (CRCs) and anti-slagging coatings (ASCs) over the past decade. CRCs are explored through thermal spray processes that include arc spray, atmospheric plasma spray (APS), high-velocity oxygen fuel (HVOF), detonation gun (D-gun™), and cold spray. Studies on alloys, ceramics, and ceramic–metal composites are summarised, highlighting the high temperature corrosion prevention mechanisms and discussing new coating materials. ASCs are reviewed in the context of advancements via thermal spray and slurry spray methods. The mechanisms for slag reduction, testing methods to evaluate ASC effectiveness, and the necessary architecture for preventing slag deposition are examined. A lab-based rig simulating fly ash deposition onto water-cooled coating coupons for anti-slagging investigations is also presented. Further research is needed to develop and evaluate materials for ASCs effectively. Graphical Abstract

Critical review of metal-ceramic composites fabricated through additive manufacturing for extreme condition applications

Metal-Ceramic composites are a special class of materials, including elements as matrix and reinforcements. These composites, especially metal matrix composites, are of great significance in several high-end engineering applications due to their tunable conductivity, strength, and toughness. This review paper summarizes studies carried out to fabricate metal-ceramic composites by additive manufacturing. Various metal matrix composites such as titanium matrix composites, cobalt matrix composites, iron matrix composites, nickel matrix composites, and aluminum matrix composites are elaborated in detail. The paper provides an in-depth analysis of applications, trends, opportunities, and outlook for additive manufacturing of Metal-Ceramic composites.

Influence of the Thickness of Titanium Foils on the Deformation Pattern in ZrO2-Based Metalceramic Composites

Influence of the Thickness of Titanium Foils on the Deformation Pattern in ZrO2-Based Metalceramic Composites

Fabrication framework for metal supported solid oxide cells via tape casting

Among the different solid oxide cells (SOCs) designs, metal supported SOCs (MSOCs) offer important advantages such as enhanced mechanical robustness, improved thermal resilience and lower material costs. The conventional tape casting method, which is used for the commercial multilayer ceramic technology, is also attractive for the fabrication of MSOCs due to its inherent scalability and cost-efficient fabrication methodology while offering a reliable product without compromising critical microstructural aspects and electrochemical performance during operation.This study is aimed at addressing the main challenges in the fabrication of MSOCs using tape casting, to provide a robust framework for the fabrication parameters, allowing the technology to advance to a more mature stage. It was shown that the dispersion of the powder particles and the physical and chemical characteristics of the binder are found to play a crucial role in obtaining defect free MSOCs and are discussed in detail. Different architectural designs of the cells (asymmetric and symmetric) and electrode configurations (ceramic and metal-ceramic composites) are studied, highlighting their strengths and challenges. The framework established within this work allowed to fabricate, reproduce and test MSOC that exhibited electrochemical performance comparable to state-of-the-art solid oxide cells (electrolysis current density of 0.6 A/cm2 at 1.3 V at 700oC, 50 % steam in H2 at fuel side and air at the oxygen side).

A comprehensive analysis of cermet design and thermal cyclic stability via elasto-viscoplastic crystal plasticity modeling

Ceramic-metal composites, or cermets, exhibit beneficial properties resulting in their use in many industrial applications. One challenge with cermets is mismatches in the coefficient of thermal expansion (CTE) values between the ceramic and metal phases that lead to residual stresses after processing, plasticity in the metal phase, internal stresses, and instability after thermal cycling. In order to make predictions of these properties to inform the design of cermets, we employ an incremental elasto-viscoplastic, self-consistent formulation to calculate the thermal, elastic, and plastic strains in two-phase polycrystalline cermet materials. This framework is extended to include temperature dependent properties, which are called implicitly within the temperature-dependent, incremental elasto-viscoplastic, self-consistent (TE-VPSC) model. Temperature-induced cooling and thermal cycling simulations are conducted using the TE-VPSC framework to study the residual stresses and plastic strains in the metal phases. Two materials are discussed in detail exhibiting stark differences based on the CTE between their ceramic and metal phases, WC/57-vol% Cu (exhibiting a pronounced CTE mismatch) and Y2O3/27-vol% Nb (exhibiting a negligible CTE mismatch). The model demonstrates high residual stresses in the Cu phase during processing and reverse plasticity leading to recovery of plastic strain during thermal cycling of the WC/Cu cermet. Moreover, the model demonstrates relatively low residual stresses and plasticity in Y2O3/Nb and a thermal stability point of 1251 °C, below which no plasticity develops in the cermet. We employ the TE-VPSC model as a design tool for cermets to systematically investigate the effects of process-induced microstructure variations (volume fraction, grain aspect ratio, and crystallographic texture are investigated) and compositional differences (19 compositions are explored) on the residual stress, degree of plasticity in the metal phase, and thermal stability point. The computational efficiency of the TE-VPSC framework makes it a desktop design tool that can be used to quantify the impact of changing composition, processing, and thermo-mechanical loading on the performance of the cermet, which can help reduce the number of time intensive and costly high temperature experiments.

Characterisation of a New Generation of AlMgZr and AlMgSc Filler Materials for Welding Metal–Ceramic Composites

When manufacturing the welded joints of components made of metal–ceramic composites of the Al-Si/SiC type, we encounter significant difficulties. This is related to the presence of a ceramic phase in the aluminium alloy matrix. The interaction between the molten metal matrix and the ceramic particles in the weld pool influences a complex of physicochemical phenomena resulting in, among other things, the structure of the welded joint. This is particularly true of the effect of the distribution of ceramic particles and their influence on the crystallisation process in the weld pool. An important issue is the influence of the reinforcing particles on the susceptibility of the aluminium matrix to both hot and cold cracking. The scope of the research included the development of the chemical composition of an additive material for the TIG welding of aluminium–ceramic composites. This material was made in the form of so-called sticks, cast from alloys containing elements such as magnesium, scandium or zirconium in addition to aluminium. The appropriate composition of the mass content of the individual components was intended to change the crystallisation mode of the weld pool and to obtain strengthening precipitates. The most favourable structure was obtained in the case of a modification of the AlMg5 alloy by the addition of scandium. Minor dispersions of Al3Sc became the nucleation pads of fine grains, which improved the mechanical properties of the alloy. Also, in the case of the addition of zirconium, the crystallisation shifted from dendritic to fine-grain growth. In this paper, the basic strength properties of the developed materials were tested and the most favourable chemical compositions of the filling materials were selected.

Graphene reinforced ceramic matrix composite (GRCMC) – state of the art

Abstract Ceramic Matrix Composites (CMC) are widely used for manufacturing automobile parts aircraft components, biomedical and electronic devices. In recent years, graphene has found extensive applications in various fields like effective reinforcement in the development of metal matrix, polymer matrix and ceramic matrix composites. Literature reveals that more focus was on polymer and metal matrix composites reinforced with graphene when compared to ceramic matrix composites. In this manuscript, the effect and suitability of graphene as a reinforcement for fabricating ceramic matrix composite are presented. Further, the property evaluation, including mechanical and physical, characterization and microstructural evaluation of the CMCs developed with graphene as reinforcement is elaborated. The investigation of the reinforcing mechanisms and failure behavior of ceramic matrix composites reinforced with graphene, together with the development of novel processing techniques to solve manufacturing difficulties, are key areas of focus. Although many investigations have concentrated on enhancing the mechanical and electrical characteristics of ceramics by integrating graphene, more investigation is required to investigate the interfacial interaction between graphene and the ceramic matrix, as well as the influence of graphene size on the properties of the composite. Furthermore, there is a need for future research to explore the possibility of using graphene-reinforced ceramic composites in several multifunctional applications, including microwave absorption, electromagnetic interference shielding, ballistic armors, self-monitoring damage sensors, and energy storage and conversion. Future research should focus on developing innovative processing procedures that guarantee the uniform distribution and precise alignment of graphene sheets within the ceramic matrix. The incorporation of graphene into ceramic matrix composites presents novel prospects for augmenting the characteristics and capabilities of ceramics, rendering it a very interesting area for further investigation.

Fracture toughness and slow crack growth behaviour of metal-proton conducting ceramic composites

The fracture toughness and slow crack growth behaviour of two load-bearing metal ceramic components adopted in negatrode-supported electrochemical devices, namely Ni-BCZY27 and Ni-BCZY442, are investigated via double torsion technique.The investigation showed that the two metal-ceramic composites are considerably less sensitive to slow crack growth when compared to oxide ceramics such as stabilized zirconia and alumina, with KI0/KIC equal to approximately 0.8. On the other hand, they also showed lower fracture toughness than Ni-3YSZ, with Ni-BCZY442 and Ni-BCZY27 having a fracture toughness of respectively 1.74 and 3.04 MPa*m1/2 for porosities equal to 25.8% and 19.1% respectively, compared to Ni-3YSZ reported in previous work with similar Ni content and porosity of approximately 30% having a fracture toughness equal to 3.4 MPa*m1/2. Furthermore, the analysis of samples presenting extensive barium depletion indicated fast fracture propagation upon application of loads significantly lower than the critical fracture load.

Development and investigation of a porous metal-ceramic substrate for solid oxide fuel cells

The process of creating a porous metal-ceramic material based on Ni-Al alloy and gadolinium-doped cerium oxide (CGO) using the thermal explosion method has been investigated. This study aims to analyze the effect of CGO on the thermal explosion parameters and the architecture of the resulting Ni-Al-CGO materials. In this regard, the influence of adding CGO powder to the Ni-Al system on the synthesis process and structure formation during controlled heat loss thermal explosion has been studied. Dependencies of temperature and time characteristics of the thermal explosion on initial parameters have been measured. It has been demonstrated that the concentration of CGO in the initial mixture and heat dissipation from the sample significantly affect the rate of the exothermic reaction. The phase composition of the obtained porous materials, depending on the CGO content and the temperature of subsequent vacuum annealing, was analyzed using X-ray diffraction. The chemical composition and microstructure of the synthesis products were examined through electron microscopy and energy-dispersive X-ray spectroscopy. The possibility of forming metal-ceramic composites with a porosity of 60–65 % for use as supporting substrates for solid oxide fuel cells with a NiO/CGO anode has been shown. An anodic layer of NiO/CGO was applied to a metal-ceramic base of the composition (Ni+25 %Al)+5 %CGO using screen printing, which was then annealed in an air atmosphere at 1300 °C and reduced at 900 °C in a hydrogen atmosphere. The dilatometric method determined that adding 40 wt.% Cr to a mixture of Ni-Al powders reduces the average coefficient of thermal expansion of the new material.

Study on the microstructure and properties of TiB2-CoCrFeNiW0.2 metal ceramic composites prepared by pressureless sintering

Three types of TiB2-HEA ceramic composite were prepared using a non-equimolar ratio CoCrFeNiW0.2 high entropy alloy (HEA) as a binder, mechanical alloying (MA), and 1600 °C pressureless sintering (PS) processes. The phase analysis results indicate the presence of TiB2, FCC, and TCP phases in the TiB2-HEA composite. A detailed study was conducted on the microstructure of TiB2-HEA composite. The results indicate that there is a certain solid solubility between TiB2 and HEA. The Ti and B elements in TiB2 will enter HEA, and the elements in HEA will also enter TiB2. Along with the discovery of many lattice distortion regions in TiB2, a diffraction pattern of P-43m cubic structure was also observed in HEA. HEA has good wettability with TiB2, so it can not only inhibit the grain growth of TiB2, but also improve the performance of TiB2-HEA composite by utilizing the inherent excellent properties of HEA. There are both intergranular and transgranular fractures in the TiB2-HEA composite. The relative density, flexural strength, Vickers hardness, fracture toughness, and electrical resistivity of TiB2-30 wt%HEA are 99.7%, 680 MPa, 18.6 GPa, 6.4 MPa m1/2, and 5.7 × 10−7 Ω m, respectively.

Kinetic Mechanisms of the Photocatalytic Generation of Hydrogen from Formic Acid Using Metal–Ceramic Composites under Visible-Light Irradiation

Kinetic Mechanisms of the Photocatalytic Generation of Hydrogen from Formic Acid Using Metal–Ceramic Composites under Visible-Light Irradiation

Digital light processing of TixOy@Ti/HA biomaterials by oxidation of TiH2 and dehydrogenation of TiO2@TiH2/HA precursors

AbstractThe complex structure of Ti/HA (HA: hydroxyapatite) implants prepared by additive manufacturing technology plays an essential role in its application in bone repair. Digital light processing (DLP) is widely used to prepare bioceramics with complex structures. However, it is a challenge to prepare Ti/HA biomaterials by DLP due to the high ultraviolet (UV) absorption of Ti powder. In the present work, TiH2 powder coated with a TiO2 layer is selected to reduce the UV absorption and improve the curing depth for DLP printed green bodies of TiO2@TiH2/HA, because the TiO2@TiH2 powder can be reduced by 12.7% compared to the TiH2 powder without any oxidation. Then, the shell layer of TiO2 undergoes dehydrogenation and reduction reaction with the core phase of TiH2 during the sintering process to transfer TiO2@TiH2/HA into TixOy@Ti/HA. In addition, the effects of HA content on compressive strength and biocompatibility are investigated in the TixOy@Ti/HA biomaterials. The results show that when adding 60 vol%HA, the maximum monolayer curing depth of the slurry reaches 90.1 ± 3.5 µm. 40%TixOy@Ti/60%HA shows the maximum effect in promoting the pre‐osteoblast differentiation and a relatively high compressive strength of 48.7 ± 3.5 MPa. This work provides an experimental basis for the preparation of ceramic–metal composites with high UV absorptivity using DLP.