Properties Of Metal Matrix Composites Research Articles

Molecular Dynamics Simulation on Solidification Microstructure and Tensile Properties of Cu/SiC Composites.

The shape of ceramic particles is one of the factors affecting the properties of metal matrix composites. Exploring the mechanism of ceramic particles affecting the cooling mechanical behavior and microstructure of composites provides a simulation basis for the design of high-performance composites. In this study, molecular dynamics methods are used for investigating the microstructure evolution mechanism in Cu/SiC composites containing SiC particles of different shapes during the rapid solidification process and evaluating the mechanical properties after cooling. The results show that the spherical SiC composites demonstrate the highest degree of local ordering after cooling. The more ordered the formation is of face-centered-cubic and hexagonal-close-packed structures, the better the crystallization is of the final composite and the less the number of stacking faults. Finally, the results of uniaxial tensile in three different directions after solidification showed that the composite containing spherical SiC particles demonstrated the best mechanical properties. The findings of this study provide a reference for understanding the preparation of Cu/SiC composites with different shapes of SiC particles as well as their microstructure and mechanical properties and provide a new idea for the experimental and theoretical research of Cu/SiC metal matrix composites.

Powder-metallurgical construction of graphene-like nanosheet network reinforced Cu composites towards balanced high-performance

The size and grain conformality of the metallurgical precursor powder significantly affect the comprehensive properties of metal matrix composites. To address this challenge, homogeneous hybrids of graphene-like nanosheets coated Cu (GLNs@Cu) particles with controllable sizes are synthesized through an in-situ decomposition of cupric tartrate. Subsequently, graphene-like nanosheet network reinforced Cu (GLNN/Cu) composites are prepared by a powder-metallurgical method from the GLNs@Cu particles based on a thermal-pressing welding mechanism. The 3D-GLNN are uniformly dispersed throughout the Cu matrix, creating an isolation structure over the Cu grains, and acting as a barrier to grain fusion resulting in grain conformality of the composites. Simultaneously, the 3D-GLNN distributes along the Cu grain boundaries establishing inter-connected pathways for the electrons, thereby maintaining high electrical conductivity while refining the grain size of the Cu composites. It is precisely because of this, the GLNN/Cu composites exhibit a tensile strength of ∼500 MPa, approximately 3 times higher than that of the pure Cu. In addition, the interlinked 3D-GLNN provides an electron transport channel for the Cu composite as well as an isolation structure from the corrosive medium, which makes the Cu composite maintain an electrical conductivity even higher than the pure Cu and a corrosion rate of 48.9 % compared with the pure Cu.

An Experimental Investigation on Mechanical and Tribological Properties of Metal Matrix Composites Fabricated with Waste Aluminum, SAC, and CDPF via Stir Casting

An Experimental Investigation on Mechanical and Tribological Properties of Metal Matrix Composites Fabricated with Waste Aluminum, SAC, and CDPF via Stir Casting

Fabrication and Characterization of a Stir Casting-Based Aluminium Hybrid MMC Reinforced with SiC, TiC, and MoS2

The need for strong, lightweight materials has prompted the creation of innovative metal matrix composites based on aluminum. The properties of metal matrix composites that are uniformly dispersed with nanoparticles are much superior to those of monolithic alloy and microparticle-reinforced composites. The objective of this work was to create and evaluate a metal matrix composite reinforced with MoS2, SiC, and TiC that is a hybrid aluminum alloy, Al6061. It was also investigated how the weight percentages (3, 6, 9, and 12%) of MoS2, SiC, and TiC reinforcement affected the mechanical, morphological, tribological, and physical characteristics of the metal matrix composite. The addition of SiC and MoS2 increased the density of the reinforced Al6061 composite when compared to as-cast non-reinforced Al6061. It was found that the hybrid composite Al6061/12% SiC/4% MoS2 had the maximum density. The hybrid metal matrix composite's toughness increased as the proportion of TiC weight increased. The composite made of Al6061, 12% TiC, and 4% MoS2 had the maximum hardness, measuring 114.03 HV. The composite Al6061/12% TiC/4% MoS2 has the most ultimate tensile strength. The tribology analysis revealed that when applied stress increased from 10 to 50 N, mass loss increased dramatically. Because of the solid MoS2 lubricant and the development of the TiC layer at the contact zone, Double- and triple-reinforced specimens had less wear loss than non-reinforced specimens, as shown by the wear performance of hybrid composites. The main wear mechanisms of the composites were delamination wear and wear debris.

A new wavy cross-sectional torsion extrusion method with an application to improve the mechanical properties of an aluminum matrix composite

Torsion extrusion (TE) as a severe plastic deformation (SPD) method has shown promise in effectively improving the mechanical properties of metal matrix composites (MMCs) by means of extreme shear strain. However, the circumferential sliding between the rotating die and the material seriously degrades the shear effects during TE processing. In order to address this challenge, a modified torsion extrusion method, namely wavy cross-sectional TE (W-TE), was proposed to enhance the shear effect. The method applied a rotating die consisting of a deformation cavity followed by a bearing segment with a wavy cross-section. The material is extruded through the rotating die, and the wavy cross-section holds the deformed billet to rotate with the rotating die, so that the relative sliding is prevented. The method was applied to an in-situ TiB2 particle reinforced 2026 Al composite for dispersing the reinforcing particles and refining the microstructures. Numerical simulations indicated that the W-TE processed material undertook larger torsion deformation than the ones processed by the conventional TE, so the shear effect was enhanced. Experiments showed that, compared with the conventional TE, W-TE can efficiently disperse the reinforced particles and refine the microstructure of the extruded materials. Mechanical tests demonstrated that the samples processed by W-TE exhibits a simultaneously increase in the strength and ductility. Furthermore, with the aid of the enhanced shear effect, the extrusion force of W-TE was reduced greatly compared with conventional extrusion or other TEs, thus making the proposed W-TE an efficient way for improving mechanical properties of metal matrix composites.

Experimental analysis and machining characterization of aluminium 356 matrix composites reinforced with fly ash and alumina oxide Al2O3

A higher specific strength, specific modulus, damping capacity, and robust wear resistance are among the many superior properties of metal matrix composites (MMCs) over unreinforced alloys. A growing body of research is focused on low-density composites with low-cost reinforcements. Regarded as one of the least costly and least dense reinforcements available in substantial quantities, fly ash is a solid waste by product that is created when coal is burned in thermal power plants. Using Al356, Fly Ash, and Alumina Al2O3, the proposed metal matrix composite is created. Consequently, it is expected that fly ash reinforced composites will break through the financial barrier and become widely used in automobile and small engine parts. The primary objective of this research is to explore the potential of fly ash-reinforced composites to overcome economic barriers and find extensive applications in automotive and small engine components. By incorporating fly ash particles into aluminum alloy, we aim to not only enhance the properties of the material but also promote a sustainable use for this abundant waste by product. To achieve our goals, we employ a comprehensive fabrication process involving the incorporation of fly ash into the aluminum matrix using stir-casting techniques. This method allows for effective mixing and the formation of composite materials with the desired properties.. Particle reinforced aluminium matrix composites are becoming more and more popular for the creation of secondary components because of their low cost, isotropic properties, and chance for secondary processing. With fly ash, an easily accessible industrial waste, mixed with aluminum and stir-cast to form composite materials, the current effort aims to identify a workable use for this material.

Effects of the Si element on the microstructure and mechanical properties of an Al/FMG/SiC hybrid composite

Enhancing the mechanical properties of metal matrix composites can be achieved through the modification of the chemical composition of the matrix. However, the specific role of silicon (Si) as an important alloying element in the context of Al matrix hybrid composites simultaneously reinforced with metallic glass and ceramic particles has not been extensively studied. Therefore, this present study aimed to investigate the effects of Si element on the microstructure and mechanical properties of an Al–Si matrix composite reinforced with SiC and Fe-based metallic glass (FMG) particles. The composite was fabricated using a powder metallurgy approach. The amount of Si was selected to position the resultant alloy solidus temperature in the super-cooled liquid region of the FMG reinforcing particles. Results showed that a small amount of Si formed an Al-rich solid solution in the Al matrix, while the rest was observed as Si-rich regions in the microstructure. Adding Si to the matrix improved densification behavior and reduced porosity content during sintering, resulting in a more homogeneous distribution of reinforcing particles. The compressive yield strength and hardness of the composite with Si in its composition were 82% and 74% higher, respectively, than the same composite without Si, confirming the effectiveness of incorporating Si in the matrix.

Investigation of mechanical properties of metal matrix composites

Aluminium is one of the lightest engineering materials. It offers a greater strength to weight ratio. Due to the numerous ways in which aluminium's advantageous properties—including strength, lightness, corrosion resistance, recyclability, and formability—can be combined; it is employed in an increasing number of structural applications. Several researchers have been evaluated in order to combine some of the components of the mechanical and wear behaviour of stir cast aluminium metal matrix composites. Aluminium 6061 alloy, in which aluminium serves as the basic element, is selected as the matrix alloy in this project. Medium-strength aluminium alloy 6061 exhibits high corrosion resistance. The 6000 series alloy with the maximum strength is 6061, it is known as a structural alloy. Two alternate weight ratios of Al2O3, SiC, and aluminium matrix have been offered for the work, which is processed using a stir casting set-up. The samples are tested, and the results are reviewed. Density, hardness, and toughness increases but the tensile strength decreases with an increase in the reinforcement percentage.

Evading the strength and ductility trade-off dilemma in titanium matrix composites through designing bimodal grains and micro-nano reinforcements

Synchronous improvement of strength and ductility is a challenging and longstanding problem in the further development and engineering applications of titanium matrix composites (TMCs). In this study, we designed a novel heterogeneously optimized TMC for the first time, which features fine grain/coarse grain (FG/CG) regions embedding in-situ interfacial submicron-TiB/micron-TiC and intragranular nano-TiB whiskers. The TMCs achieved a strength-ductility combination, representing a nearly 30% increase without any reduction in ductility compared with the matrix alloy. The bimodal structures of the TMCs, as well as the micro-nano reinforcements and their interfacial/intragranular distribution, play a predominant role on the strengthening-toughening effect. Besides, the various dislocation behaviors including multiple slips, slip transmission across grain boundaries and activation of more 〈c + a〉 dislocations near the reinforcements, contribute to the desirable ductility. These findings highlight the untapped potential for improving mechanical properties of metal matrix composites.

Al/Al-B4C Dairesel Hibrit Kompozitlerin Mekanik Özelliklerinin İncelenmesi

Hybrid composites are material types obtained by combining two different composite structures. In this study, the mechanical properties of the circular hybrid composite materials which was produced in the form of rod with aluminum sheath and metal matrix composite core (Al-Ceramic mixture) were investigated under compression and bending loads. Although some mechanical properties of metal matrix composites (MMC) are improved with ceramic reinforcement, some of their properties as deformation ability is reduced. It was aimed to increase them by forming aluminum sheath on the outside of these materials. Al7075 aluminum alloy was used as sheath material while Al2124 alloy and B4C were used as core material. Extrusion process was used to produce the composite rods. The extrusion billets were produced with PIT (powder in tube) method. In this method, Al2124-B4C powder mixture was compressed in Al7075 tubes. Al2124-B4C powder mixture was prepared volumetrically at three different ratios (% 5, % 10 and % 15). The extrusion operation was realized at constant temperature (500 °C) and constant extrusion rate (R=14) and the composite rods produced in 8 mm diameter. The composite bars produced with and without sheaths were subjected to compression and three-point bending tests. According to the test results, with increasing of the B4C ratio in MMC bars, the deformation rate decreased rapidly. In the composites produced as hybrid, it was seen that the deformation ability increased and this showed that the aluminum sheath provided the desired improvement.

Effect of the CNTs into SiCp-Al interfacial micro-zones on ageing precipitation behavior, microstructure and mechanical properties of SiCp(CNT)/Al–Zn–Mg–Cu composites

For Al–Zn–Mg–Cu matrix composites, the introduction of reinforcements tends to have a significant effect on the aging precipitation behavior of the interfacial micro-zones, which in turn affects the mechanical properties of the composites. In this study, the ageing precipitation behavior, microstructure and mechanical properties of SiCp(CNT)/7075Al composites were systematically investigated, to explore the effect of CNT introduction on SiCp-Al interfacial micro-zones. The results showed that the introduction of SiCp(CNT) hybrid reinforcement could promote the aging precipitation behavior of the composites compared with 7075Al. But the introduction of CNTs leads to a further increase of O content in the composite compared with SiCp due to the adsorption of oxygen by CNTs, leading to more severe segregation of Mg and O, which intensified the degree of adverse interface reactions. This adversely affects the aging precipitation behavior of the interfacial micro-zones and the mechanical properties of the composites. Furthermore, the degree of interface reaction can be effectively regulated by adjusting the heat treatment process of SiCp(CNT)/7075Al composites. Compared with the T6 treatment (solid solution treatment at 475 °C for 1 h, aging treatment at 120 °C for 24 h), the yield strength and ultimate tensile strength of both 15 wt % SiCp/7075Al and SiCp(0.5CNT)/7075Al composites can be increased by more than 100 MPa under the optimal heat treatment process (solid solution treatment at 470 °C for 40 min, aging treatment at 120 °C for 15 h). Moreover, the SiCp(0.5CNT)/7075Al composite showed the best balance between strength and ductility, not only the strength was equivalent to that of SiCp/7075Al, but also the elongation increased by 13.2%. This study can provide guidance and suggestions for regulating the aging precipitation behavior of interfacial micro-zones and mechanical properties of metal matrix composites.

Interface characteristics and reinforcement mechanism of large-size WC-18Co reinforced Fe-matrix composites

WC-Co hard alloy has advantages of high hardness, high melting point and excellent wear resistance and thermal stability, its significant effect to the mechanical properties of metal matrix composites (MMCS). In order to obtain FMCS with excellent comprehensive properties, the influence of large-size WC-18Co particles on FMCS was studied. In this paper, WC-18Co/Fe composites were prepared by infiltration casting method. The phase composition, microstructure and interface characteristics of WC-18Co/Fe composites were studied. The residual stress, microhardness and wear resistance of WC-18Co/Fe composites were tested. The result shows that large-size WC-18Co particles have an effect of solid solution strengthening and dispersion strengthening. Nano-compounds and twins are produced in the transition layer, resulting in dislocation reinforcement of FMCS. The large-size WC-18Co particles generate residual compressive stress under the action of thermal stress. Elemental diffusion forms a special interface structure at the junction. The large-size WC-18Co particles improve the tribological properties of FMCS.

Effect of Chlorine Salts on TiC Coating Morphology and Bonding Strength of Diamond Surface in Molten Salt Reaction

To obtain a high-quality TiC coating on the diamond (D) surface and improve the interfacial properties of metal matrix composites, the optimized molten salt method is used to prepare TiC coatings on the D surface. The effects of NaCl, KCl, and NaCl–KCl molten salts on the uniformity, surface morphology, composition, and bonding ability of TiC coatings are investigated by scanning electron microscopy, energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction, and cold–hot cycling experiments. The results show that the boiling and pickling processes after the molten salt reaction can effectively remove the residual chloride salts and Ti powders to obtain clean TiC-coated D. The TiC particles of the coating surfaces prepared by NaCl and KCl molten salts are finer and more uniform, which is due to their higher melting points and shorter real reaction time compared with NaCl–KCl mixed salts. The TiC coating prepared by KCl has the best bonding ability and can withstand 50 times as many cold–hot cycles due to its uniform fine deposition particles and appropriate thickness. And, during cold–hot cycles, it can be found that the TiC coating cracking and shedding occur primarily at the edges and corners of the D with internal thermal stress concentration.

Study on the mechanical behaviour of metal matrix composites (MMC)

Combining two or more different base metals to create Metal Matrix Composites (MMC) results in the creation of new metals. Compared to their underlying material, composites offer superior characteristics. In today's industrial sectors, composites are notably important in the automobile sector. In order to create a novel composite using the stir casting process at standard ambient temperature, this work describes the reinforcing of the aluminium alloy with silicon carbide and copper in various ratios. Materials having metals as the base and separate, usually ceramic phases added as reinforcements to improve the characteristics are known as metal matrix composites. Whiskers and particles are examples of possible reinforcements. By changing the type of ingredients and their volume percent, the properties of metal matrix composites can be adjusted. They provide a superior mix of qualities that no monolithic material currently in use can match, and as a result, the aerospace and automotive industries are using them more frequently. MMCs' main advantage over other materials is their increased strength and hardness per unit weight. In this study, the tensile strength, hardness, and flexural strength of the composite were assessed. Sample 2 was discovered to have a maximum tensile strength of 175 MPa and a hardness of 71. The outcome demonstrates that the hybrid composite has superior mechanical characteristics.

КЭ моделирование микрогеометрических параметров композитов для оценки их упруго-прочностных свойств

The article presents the results of theoretical, finite-element and experimental determination of the elastic and strength properties of composite materials (CM) based on a metal matrix. The material in question is unidirectional magnesium carbon. Finite element modeling was carried out in linear and nonlinear formulation. The influence of surface defects of carbon fiber on the strength of the composite as a whole is analyzed. The results of the study showed the need to take into account the micro-geometric parameters of the structure and surface defects of reinforcing fibers when determining the strength properties of metal matrix composites. As a result of the research, a new technique for modeling CMs was obtained, which makes it possible to obtain refined mechanical characteristics of composites at the stage of design calculations

Evaluation of Properties of MMC Al 6061 with Boron Carbide and Silicon Carbide as Reinforcements

This research examines the properties of metal matrix composites (MMCs) made from aluminium 6061 T6 with boron carbide and silicon carbide. Aluminium material is a matrix metal with appealing features such as lightweight in nature, high strength and machining with ease. Stir casting is less expensive, simple and used for mass production of MMCs. By adding B4C as (2%, 4%, 6% and 8%) and SiC as constant (5%) reinforcement, the samples are fabricated. The hardness in the material tends to extend by adding the proportion of reinforcement in the metal matrix. Increasing the content of B4C and SiC particles, the MMCs have superior wear resistance.

Stir Casting and Successive Rolling of Aluminium Alloy 2218 MMCs Reinforced by High-Entropy Alloy Particles

Al0.5CoCrFeNi high-entropy alloy (HEAp) reinforced AA2218 metal matrix composites (MMCs) by stir casting and successive rolling. Mechanical characteristics of the AA2218 HEAp MMCs are analysed. The stir-casted AA2218 HEAp MMCs' ultimate tensile strength rose by 74.3 percent when HEAp was added at a weight percentage of 4 wt percent. When the MMCs were made by rolling, they had greater mechanical qualities than those made by RTR. Higher rolling deformation and lower HEAp mass fraction led to greater mechanical characteristics discrepancies between the AA2218 HEAp MMCs formed by CR and RTR. In the AA2218 HEAp MMCs after RTR, there were voids that were not present in the CR MMCs. Micro holes and the mechanical properties of metal matrix composites were also discussed in detail.

Influence of process parameters on the particle–matrix interaction of WC-Co metal matrix composites produced by laser-directed energy deposition

The prediction of the in-service behaviour of metal-matrix composites produced by laser-directed energy deposition is a fundamental challenge in additive manufacturing. The interaction between the reinforcement phase and the matrix has a major impact on the micro and macroscopic properties of these materials. This interaction is fostered by the exposition of the materials to high temperatures. Hence, it is highly influenced by the thermal cycle of the manufacturing process. In this work, an experimental approach is adopted to determine the influence of the main process parameters on the properties of metal-matrix composites. Statistical regression models are employed to consider the role of the most relevant parameters, from exploration to exploitation. The obtained trends are further corroborated by the corresponding microstructural, SEM, and EDS analyses. In terms of surface hardness, the DOE reveals different trends of the response depending on the composition of the feedstock employed. It is concluded that the strengthening behaviour of the material varies throughout the experimental domain studied. When high WC% feedstocks are employed, the main strengthening mechanism responsible for the increase of hardness is the solid-solution of tungsten and carbide precipitation. On the contrary, when low WC%s are employed, grain refinement becomes the main strengthening mechanism.

Solvent-Free Carbon Nanotube Nanofluid-Reinforced Copper Matrix Composites with Enhanced Mechanical Properties

Solvent-free nanofluid displays liquid-like function in the absence of solvent at room temperature by grafting organic salts on the surface of materials. In this study, carbon nanotube (CNT) fluid is synthesized by a chemical grafting method for the preparation of CNTs/copper (Cu) composite powder. After hot-pressing and sintering, the CNTs-fluid/Cu composites are further treated by hot rolling to improve their mechanical properties. The microstructure and mechanical properties of the as-obtained composites are systematically characterized by SEM, TEM, FTIR, Raman, rheological analysis, hardness and tensile tests. It is demonstrated that the optimal mechanical properties of the composite can be achieved by adding 0.75[Formula: see text]wt.% CNTs nanofluid. The yield and tensile strength of the resultant material are about 397.6[Formula: see text]MPa and 517.5[Formula: see text]MPa, respectively, which are 282% and 156% higher than that of pure Cu. Meanwhile, its hardness value reaches 152.2[Formula: see text]HV, which is increased by 27% and 38% of pure Cu and the unrolled sample, respectively. Such significant property improvement is conjointly contributed by load transfer strengthening, Orowan strengthening, matrix strengthening and thermal mismatch. This study provides a new insight into the interface structure to enhance the mechanical properties of metal matrix composites.

Influence of the High-Voltage Discharge Treatment of Powders on the Properties of Metal Matrix Composites of the Ti–TiC System

Influence of the High-Voltage Discharge Treatment of Powders on the Properties of Metal Matrix Composites of the Ti–TiC System