Formation Of Aluminum Carbide Research Articles

The influence of interface products on the mechanical and electrical properties of graphene aluminum composites

Graphene has been identified as an efficient filler to increase the strength and conductivity of aluminum but the reaction between aluminum and graphene at elevated temperature is inevitable. In this research, diverse interfacial products between aluminum and graphene were generated by modulating the sintering temperature, and their influences on the mechanical and electrical characteristics of graphene-aluminum composites were examined. Copper encapsulation on graphene has been utilized to isolate graphene from contacting aluminum directly as well as to doping graphene for conduction purposes. The synthesis of copper-coated graphene-reinforced aluminum composites involved several steps, including electrochemical exfoliation, electroless chemical deposition, mechanical ball milling, and high-pressure sintering. The results demonstrate that the formation of a solid solution between copper nanoparticles and aluminum promotes strong interfacial bonding with graphene, leading to a 22.76 % improvement in the conductivity of the composite compared to the pristine aluminum matrix. Additionally, by minimizing the formation of aluminum carbide, the addition of graphene results in a tensile strength of 404 MPa for the composite material, representing a significant 88.8 % increase over the aluminum matrix.

Aluminum carbide formation in Al-graphite composites: In situ study and effects of processing variables and sintering method

The particulate-reinforced aluminum–matrix composites are interesting due to their attractive physical and mechanical properties over their monolithic counterparts, which are related to their prominent structural differences. The effect of interfacial reaction on the mechanical properties of the Al composites has been attributed to the influence of the reaction product. In this work, the formation of Al4C3 in Al-Gr compounds prepared by high-energy ball milling and sintered by high-frequency induction is compared with a conventional method of sintering: cold compaction and furnace sintering. The conditions related to the generation of this carbide and a precise temperature in which the initial generation of this phase occurs were determined. The different results and the in-situ characterization using HR-TEM showed the substantial reactivity of graphite in the aluminum matrix, leading to the formation of the Al4C3 phase within a few seconds of heating to 250 °C. The conventionally sintered samples displayed the highest number and size of Al4C3 precipitates. In contrast, the heated sample exhibited varied quantities and sizes of these precipitates. Notably, the high-frequency induction sintered samples contained smaller Al4C3 precipitates with a lower number density. Structural, microstructural, and chemical composition results of this phase formed in Al-Gr composites are also shown.

INVESTIGATION OF CARBON-ALUMINUM COMPOSITE WITH A BARRIER COATING ON CARBON FIBERS

Barrier SiO2 coatings on the surface of carbon fibers were deposited by the sol-gel solutions (dip coating) based on tertraethoxysilane Si(C2H5O)4. The average thickness of the barrier SiO2 coating on carbon fibers is 127 ± 30 nm. Carbon-aluminum composites were obtained by a type of liquid-phase infiltration — by the shell molding process. The components of the composite were placed in a steel hermetic shell, then after the shell evacuate and heat until the aluminum melts, the fibers were infiltrated by the melt under the external pressure, followed by cooling. Composites with SiO2 coating and without coating on carbon fibers were obtained. After extracting the composite from the metal shell, the structure, phase composition, and mechanical properties of the samples were studied. Studies of the structure of composites showed that the interfiber space is filled with aluminum melt, without porosity and macroscopic defects. The study of the phase composition of the composite reinforced with uncoated carbon fibers showed that aluminum carbide peaks are observed at the angles 2θ = 41°, 67°, 74°. Quantitative analysis carried out by the Rietveld method revealed that the amount of aluminum carbide in the composite is 12.0 ± 1.3 %. The deposition of a barrier SiO2 coating on carbon fibers leads to a decrease in the intensity of the main peaks of aluminum carbide, while the amount of Al4C3 decreases by 4 times, to 3.0 %. An analysis of the fracture surface of the samples after mechanical testing revealed that the fracture of the composite reinforced with uncoated carbon fibers is almost flat. No protrusions and relief are observed on the fracture surface. The fracture surface of a composite reinforced with coated carbon fibers has a relief surface, and separately sticking out fibers are observed. Mechanical tests of samples for three-point bending showed that the barrier coating on the fibers increases the strength to 520 ± 50 MPa, the strength of the uncoated composite is 350 ± 8 MPa. Barrier SiO2 coating applied to the surface of carbon fibers prevents the formation of aluminum carbide and fiber degradation in the carbon-aluminum composite.

Effect of uncoated and coated diamond on the compressive properties of porous aluminium composites

AbstractPorous aluminium composites are structural and functional materials that have vast potential, due to their lightweight and high energy absorption capacity, especially in automotive and aerospace applications. In this study, the effect of varying content of uncoated and titanium coated diamond particles on the compressive properties of porous aluminium composite was investigated. The composites were developed using powder metallurgy technique and porosity was attained by using polymethylmethacrylate (30 wt.%) as space holder material. The morphology of the pores was found to replicate the shape and size of polymethylmethacrylate particles, that were uniformly distributed in the composites. X‐ray diffraction analysis confirmed formation of aluminium carbide in uncoated diamond‐based aluminium composites while negligible amount was present in titanium coated porous composites during sintering. The porosities of composites decreased with an increase in diamond content due to the incomplete decomposition of polymethylmethacrylate particles. Moreover, the maximum plateau stress and energy absorption capacity of 9.96 MPa and 1.7 Mj/m3 were obtained for the composites with 8 wt.% of titanium coated diamond particles. Thus, coating inhibits the formation of undesirable compounds and contributes to better interfacial bonding between matrix and reinforcement.

Interfacial structure-property relationship in a carbon nanotube-reinforced aluminum alloy matrix composite fabricated by an advanced method

In our previous study, a bulk carbon nanotube (CNT)-reinforced aluminum alloy matrix composite with enhanced comprehensive mechanical properties was fabricated via an advanced powder processing, denoted as Mixed Ball-Milling (MBM) technique. Here, we attempted to explore the relationship between the composite microstructure and the elevated mechanical behavior with a special focus on CNT/Al interfacial features. To this end, high-resolution scanning transmission electron microscopy (HRSTEM) imaging combined with Raman spectroscopy were conducted to take a panoramic view of the subject. It was shown that in addition to the matrix heterogeneous grain structure and maintaining the structural integrity of CNTs, the interfacial bonding structure can be tailored using MBM methodology. Indeed, the formation of aluminum oxide nanophases in and around acid treatment-induced oxygen defects not only contributed to CNT structural conservation but also facilitated the load-transfer capability of the composite. A semi-quantitative analysis, performed on Raman spectroscopy data, authenticated that the aluminum carbide (Al4C3) formation was significantly restricted in the MBM processing, probably due to the presence of oxide species. The findings may also grant insight into the seldom-studied role of surficial oxygen defects in carbon-containing metal matrix composites.

Study of interfacial behavior on the damping characteristics of aluminum (Al)-Carbon nanotubes (CNTs) nanocomposites

In this work, MWCNTs-multi-walled carbon nanotubes of distinct reinforcement with Al matrix composite were fabricated by a novel route of dispersing Al-CNTs precursor, then integrated with compaction technique and sinter-forged process. The microstructural and dynamic behavior of as-produced Al-MWCNT composites were investigated, and the interfacial reaction was studied on the damping behavior of Al-CNT nanocomposite. Findings reveal a formation of aluminum carbide (Al4C3) formation at Al-CNT interface layers. A reaction arose at locations with an amorphous carbon coating at open ends of CNTs, in as-produced Al–CNT composites, carbon nanotubes with a wt. % of 0.75 has a solid interfacial interaction and obtained a damping capacity of 875 × 10−3 and a storage modulus of 82.9 GPa with a frequency of 1 Hz. This results in effective load transmission between the Al matrix and CNT, improving the dynamic behavior of the composite. However, the formation of the aluminum carbide phase contributes to the damping capacity of the aluminum reinforced with the wt. % of 0.75 and 1.0 CNT composite, which increases by 40 % and 21 % as compared to pure Al, whereas CNTs are identified as a capable coating for Al matrix to raise high absorb capacity at elevated temperatures subjected to the formation of Al4C3 phase without losing the mechanical behavior of the Al matrix.

Synthesis of nitrogen-doped graphene and its strengthening effect on aluminium metal matrix composite

The present study investigates the potential of nitrogen-doped graphene nanosheets (NDG) as a reinforcing material in aluminum (Al) metal matrix composites. The NDG was synthesized through a mechanochemical process involving solid-state dry ball milling of graphite with melamine. Characterization techniques such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), and Raman spectroscopy were used to evaluate the properties of the NDG. For the first time, NDG was employed as a reinforcing material to improve the wettability, minimize the formation of aluminum carbide, and enhance the strength through strong interfacial bonding. The ultimate tensile and compressive yield strengths of Al/NDG composites were found to be 124% and 67% higher, respectively, with only 0.2 wt% NDG content. Furthermore, the tensile strength of the 0.2 wt% NDG/Al composite was found to be 72% higher than that of the 0.5 wt% graphene/Al composite. The fractured surface of the Al/NDG composite was investigated by XRD and FESEM techniques. XRD analysis revealed the presence of low-intensity peaks of aluminum nitride (AlN) and no evidence of aluminum carbide. The tribological properties of NDG were studied through wear rate and coefficient of friction (COF) measurements. The results showed a decrease in COF by 45% with an increase in NDG concentration from 0.1 to 0.5 wt%, and a decrease in wear rate by 25% and 71% for the same NDG concentration range. These results provide insight into the potential of NDG as an additive to improve tribological properties in aluminum-based composites. Further research is needed to understand the underlying mechanisms and optimize the performance thoroughly.

Effect of SiO2 Surface Oxidation Coating of Silicon Carbide Particles Reinforcement on the Mechanical Properties of Al-2.5%Mg/xSiCp Developed by Stir Casting Method

The literature revealed that composites developed through stir casting process suffer some limitations such as low wettability and insufficient bonding between the molten Al and SiCp and the formation of aluminium carbide (Al4C3) at the interface which degrades mechanical performances of the composites. To overcome these challenges, this study used magnesium for improved wettability, heat treatment of reinforcement particles (SiCp) and application of metallic (SiO2) coating on the SiCp before addition to melt to improve Al-SiCp wettability in the manufacture of Al-2.5%Mg/xSiCp composites. The SiCp coating reduce direct interaction and promote wetting between SiCp and molten Al to developed Al-2.5%Mg/xSiCp composites. The percentage weight of SiCp varied from 5 wt% to 20 wt% (uncoated and coated) at 5 % intervals. The mechanical properties tests were conducted to examined the effects of coating and variation of volume percentage of SiCp on the composites developed. The results obtained showed that the reinforced alloy with both uncoated and coated SiCp performed favorably well compared to the control sample with 0% SiCp. The improvement of interfacial strength was observed in the composites developed with coated SiCp as the coating of SiCp enhanced its diffusion with Al-2.5%Mg.

Effect of high-energy ball milling on the microstructure, phase composition and microhardness of the Al–Mn–Cu alloy

X-ray diffraction and scanning electron microscopy methods were used to study the effect of the planetary ball mill treatment time on the morphology, phase composition and microstructure of the Al–Mn–Cu-based alloy granules with and without nanodiamond particles. The phase composition of the alloy was determined by X-ray diffraction after casting and milling for 5–20 h. It was shown that nanodiamond particles promote granule coarsening, and this is especially noticeable with an increase in the milling time up to 20 h. At the same time, the size of initial alloy granules weakly depends on the processing time. Cu-bearing phases of crystallization origin dissolve during mechanical alloying. The lattice constant of the aluminum solid solution decreases after 5-hour treatment to 0.4028–0.4030 nm, and increases with further increasing milling time. Exothermic effects associated with the precipitation of secondary phases were revealed for mechanically alloyed granules during heating. An increase in the milling time reduces the intensity of peaks. The solidus temperature of samples decreased after mechanical alloying. For the nanodiamond-bearing sample, an exothermic effect is observed which can be ascribed to the aluminum carbide formation or oxidation reactions in nanodiamond particles. The maximum microhardness is achieved after 5–10 h of mechanical alloying, and the nanodiamond particles slightly increase the maximum microhardness from 316 to 330 HV. The results indicate the dissolution of copper and manganese in the aluminum solid solution after 5 h of treatment and their precipitation with the increasing milling time. Nanodiamond particles have no effect on the dissolution of elements but accelerate the solid solution decomposition with the increasing treatment time.

Peculiarities of chemical interaction of some carbon nanoreinforcements with aluminum matrix in metal matrix composite (MMC)

AbstractThe possibility of applying globular carbon for reinforcing the aluminum matrix when using mechanical alloying to produce composites was shown by investigating specific properties of chemical interaction of nanocarbon with the aluminum matrix. The structure of the initial particles of globular carbon and composite granules was studied. Mechanical alloying can significantly crush the initial particles of globular carbon. The use of the method of differential scanning calorimetry allowed the temperature of the start of the reaction between globular carbon nanoparticles and aluminum matrix with the formation of aluminum carbide to be determine as 320 °C–350 °C. Aluminum matrix composites with reinforcing particles of globular carbon can be used up to these temperatures without risk of the formation of aluminum carbide.

Mechanical properties of metal–matrix composites reinforced with carbide structures

Metal–matrix composites based on an aluminum matrix reinforced with ceramic particles are widely used as structural materials in the aerospace and automotive industries. The main problems in the manufacture are the uniformity of the distribution of particles over the volume, poor adhesion of ceramic particles to the matrix metal, and the formation of aluminum carbide at the interfaces, leading to undesirable embrittlement. We propose a new technique for the manufacture of metal–matrix composites, which consists in creating a composite material, when carbide nanostructures form a framework in the volume of an aluminum matrix, and which allows solving the above problems. A finite element model of deformation of a metal–matrix composite reinforced with carbide structures is constructed.

Laser Fusion of Aluminum Powder Coated with Diamond Particles via Selective Laser Melting: Powder Preparation and Synthesis Description

This work aims to study the possibility of obtaining Al–C composite from AlSi10MgCu aluminum matrix with the addition of 500 nm-sized diamond particles by selective laser melting (SLM) process. Al–C composite powder was prepared by mechanical mixing to form a uniform cover along the surface of aluminum particles. The diamond content in the resulting AlSi10MgCu-diamond composite powder was equal to 0.67 wt %. The selection of the optimal SLM parameters for the obtained composite material is presented. For materials characterization, the following methods were used: scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Raman spectroscopy. X-ray photoelectron spectroscopy (XPS) was applied after SLM printing for a detailed investigation of the obtained composites. The presence of carbon additives and the formation of aluminum carbides in the material after the SLM process were demonstrated.

Li-ion storage properties of two-dimensional titanium-carbide synthesized via fast one-pot method in air atmosphere

Structural bidimensional transition-metal carbides and/or nitrides (MXenes) have drawn the attention of the material science research community thanks to their unique physical-chemical properties. However, a facile and cost-effective synthesis of MXenes has not yet been reported. Here, using elemental precursors, we report a method for MXene synthesis via titanium aluminium carbide formation and subsequent in situ etching in one molten salt pot. The molten salts act as the reaction medium and prevent the oxidation of the reactants during the high-temperature synthesis process, thus enabling the synthesis of MXenes in an air environment without using inert gas protection. Cl-terminated Ti3C2Tx and Ti2CTx MXenes are prepared using this one-pot synthetic method, where the in situ etching step at 700 °C requires only approximately 10 mins. Furthermore, when used as an active material for nonaqueous Li-ion storage in a half-cell configuration, the obtained Ti2CTx MXene exhibits lithiation capacity values of approximately 280 mAh g−1 and 160 mAh g−1 at specific currents of 0.1 A g−1 and 2 A g−1, respectively.

On the Strength of the CF/Al-Wire Depending on the Fabrication Process Parameters: Melt Temperature, Time, Ultrasonic Power, and Thickness of Carbon Fiber Coating

The process of the production of a CF/Al-wire by pulling carbon fibers through an aluminum melt has at least 15 parameters. The main parameters include the power of ultrasonic treatment, the time of contact of the fiber with the matrix melt, and the melt temperature. In addition, the presence of a barrier coating on the fiber surface and its thickness significantly affects the properties of the resulting material. The importance of these parameters is due to their direct effect on the chemical interaction between the aluminum matrix and the carbon fiber. This interaction leads to the formation of aluminum carbide, a hygroscopic, brittle phase that ultimately significantly reduces the strength of such composites. In this regard, limiting a chemical reaction at the matrix/fiber interface in the production of CF/Al composites is one of the main technological problems. The main goal of this work is to pragmatically elucidate the effect of the above parameters on the strength of CF/Al composites. It is shown that the strength of a CF/Al-wire can reach 2000 MPa.

Characterization of Aluminum Alloy–Silicon Carbide Functionally Graded Materials Developed by Centrifugal Casting Process

The continuous development of modern industries rises the necessity for functionally graded materials. This research starts from the consideration that the incorporation of SiC particles in the molten aluminum alloy can be difficult due to the very low wettability of SiC particles. In order to increase their wettability, SiC particles were covered with a layer of metallic copper. The incorporation of SiC particles into the aluminum alloy mass was performed by centrifugal casting. The secondary hypoeutectic Al-Si alloy used in this study was elaborated within the crucible of a resistors heated furnace. The metallic coating of SiC particles, in addition to the effect of increasing their wettability by molten metal, also has a role in preventing the formation of aluminum carbide in case of heating above 700 °C. A great amount of attention was paid to the parameters used during the centrifugal casting process. The results showed that adjusting the proportion of SiC particles within the composite allows us to obtain values of the thermal expansion coefficient within previously established limits. The present work demonstrates that the coating of SiC particles covered with a thin layer of metallic Cu creates the conditions to easily incorporate them into the molten Al mass, thus obtaining FGMs with controlled properties.

Ultra‐Robust Flexible Electronics by Laser‐Driven Polymer‐Nanomaterials Integration

AbstractPolyethylene terephthalate (PET) is the most widely used polymer in the world. For the first time, the laser‐driven integration of aluminum nanoparticles (Al NPs) into PET to realize a laser‐induced graphene/Al NPs/polymer composite, which demonstrates excellent toughness and high electrical conductivity with the formation of aluminum carbide into the polymer is shown. The conductive structures show an impressive mechanical resistance against >10000 bending cycles, projectile impact, hammering, abrasion, and structural and chemical stability when in contact with different solvents (ethanol, water, and aqueous electrolytes). Devices including thermal heaters, carbon electrodes for energy storage, electrochemical and bending sensors show this technology's practical application for ultra‐robust polymer electronics. This laser‐based technology can be extended to integrating other nanomaterials and create hybrid graphene‐based structures with excellent properties in a wide range of flexible electronics’ applications.

Micromechanics-based modeling of elastic modulus and coefficient of thermal expansion for CNT-metal nanocomposites: effects of waviness, clustering and aluminum carbide layer

A micromechanical model is analytically developed to estimate the elastic modulus and the coefficient of thermal expansion (CTE) of the carbon nanotube (CNT)-reinforced metal matrix nanocomposites (MMNCs). The effects of two important microstructural features, including the CNT clusters and the waviness on the thermo-elastic response are investigated. The formation of aluminum carbide (Al4C3) layer due to the interaction between the CNT and the metal matrix is considered. A good agreement is found between the available experimental data and the simulation results considering the waviness, clustering, and Al4C3 interphase. The influences of volume fraction, and dispersion type of CNTs and Al4C3 layer thickness on the elastic modulus and the CTE of the CNT-metal nanocomposites are examined. The non-straight shape and the clustering of CNTs are two critical factors that can significantly degrade the thermo-elastic properties. From the mechanical viewpoint on designing the CNT-metal nanocomposites, producing the homogeneous microstructure without the CNT clusters and using the straight CNTs are necessary factors to obtain the maximum level of the thermomechanical performances. The numerical results show that the formation of the Al4C3 interphase may improve the MMNC macroscopic engineering constants. It is observed that aligning the CNTs into the metal matrixes leads to a significant improvement in the MMNC thermo-elastic properties. The proposed micromechanical approach can be a suitable model to predict the elastic modulus and the CTE of the CNT-reinforced MMNCs considering the important microstructural features.

Manufacturing of Continuous Carbon Fiber Reinforced Aluminum by Spark Plasma Sintering

In the field of metal matrix composites (MMC), spark plasma sintering (SPS) technique has been used so far for the manufacture of particle, whisker and short-fiber reinforced alloys. In this work, SPS technique is employed for the first time to produce continuous fiber reinforced light metals. For this purpose, metal matrix composite prepregs with aluminum as a surface coating on carbon fiber textiles are manufactured by twin arc wire spraying and subsequently consolidated by SPS in the semi-solid temperature range of the alloy. Shear thinning rheological behavior of the metal alloy at temperatures between solidus and liquidus enables the infiltration of fiber rovings under reduced forming loads. SPS offered a better controlled and more efficient heat transfer in the green body and faster consolidation cycles in comparison with alternative densification methods. Fully densified samples with no porosity proved the suitability of SPS for densification of MMC with a remarkable stiffness increase in comparison with samples densified by thixoforging, an alternative consolidation method. However, the pulse activated sintering process leads to a quite strong fiber/matrix adhesion with evidence of aluminum carbide formation.

Effective functionalisation of carbon nanotubes for reinforcement application in liquid state processed aluminium composites: A relatively greener approach

This paper outlines an innovative approach to functionalise multiwall carbon nanotubes at a reduced functionalisation time and energy consumption, preserving their structural integrity, with objective of potential application of the carbon nanotubes as reinforcement in aluminium matrix composites processed through liquid state method. Longstanding problems of aluminium carbide formation as reaction by-product in aluminium matrix composites is expected to be reduced by reinforcing the carbon nanotubes functionalised through the developed method. Carbon nanotube surfaces were oxidised following four different methods using solutions of different acids at different parametric combinations, and the best possible method was identified through dispersion stability test, Fourier-transform infrared spectroscopy, scanning electron microscopy, Raman spectroscopy and thermogravimetric analysis. Results revealed that primary oxidation by 6M HNO3, followed by subsequent oxidation by weak acid H2O2 generated functionalised carbon nanotubes with satisfactory dispersion stability, preserved graphitic structure, high degree of structural integrity, less structural distortion and less carbon nanotube fragmentation.

Peculiarities of fullerenes and carbon onions application for reinforcing the aluminum matrix in the metal matrix composites

Aluminum matrix composites with fullerenes and carbon onions as reinforcing nanoparticles were studied by X‐ray diffraction (XRD) and differential scanning calorimetry (DSC). Composites were produced by mechanical alloying. It is demonstrated that aluminum carbide formation (the reaction proceeds between aluminum and carbon nanoparticles) starts at 300 to 370°C, which is much lower compared with the starting temperature of the reaction between aluminum and carbon macromaterials.