Particle-reinforced Composite Materials Research Articles

On the Preparation and Wear Properties of Ceramic Particle-reinforced High-chromium Cast Iron-based Surface Composite Material

In this study, we successfully developed a composite material that can enhance the local wear resistance of high-chromium cast iron matrix by using 203 and ZTA (ZrO2-toughened Al2O3) ceramic particles and high-chromium cast iron as the basic raw materials, using the preparation methods of melt casting infiltration and porous ceramic preform. The specific operation steps were as follows: firstly, nickel treatment was carried out on the ceramic fragments, and then the treated ceramic fragments were mixed with the preset adhesive and poured into a mold with honeycomb-shaped voids. After pressurization and heating, its texture gradually strengthened, and finally a porous ceramic preform with a honeycomb shape was formed. After that, the preform was stably placed inside the sand mold to prevent the casting from getting worn. After that, it was filled monolithically and penetrated by a high-chromium cast iron metal fluid, thus forming a composite wear-resistant layer composed of ceramics and metals.

Prediction of particle-reinforced composite material properties based on an improved Halpin–Tsai model

This paper introduces an improved Halpin–Tsai model to predict the mechanical, thermal, and electrical properties of silicon-carbide-reinforced polypropylene composites. The model considers the influence of porosity and corresponding silicon-carbide volume fractions and derives relationships between material property shape factors and the aspect ratio, silicon-carbide volume fraction, and porosity. The improved model’s predictions exhibit errors of 4.00% for mechanical properties, 2.13% for thermal properties, and 2.24% for electrical properties when compared to finite element analysis. This study demonstrates that the improved Halpin–Tsai model can effectively predict the properties of silicon-carbide-reinforced polypropylene composites, aiding in the design and optimization of these materials.

Finite element method with 3D polyhedron-octree for the analysis of heat conduction and thermal stresses in composite materials

Applying the hybrid flux finite element method(HF-FEM) and hybrid thermal stress finite element method (HTS-FEM) is not prevalent in analyzing heat conduction and thermal stresses in particle-reinforced composite materials. Most of the research on this technique is confined to two-dimensional problems. This paper proposes the HF-FEM and HTS-FEM, based on 3D polyhedron-octree, to calculate the steady-state heat conduction and thermal stress of particle-reinforced composites. In addition, this paper presents a method for partitioning spherical particle-reinforced materials into polyhedron-octree elements, each of which contains only one type of material. Each element is divided into multiple Delaunay tetrahedrons, and hammer integration is used to perform the integrals. Additionally, this paper presents a technique to construct the heat flux function for polyhedral elements, and the effectiveness of the above methods is demonstrated by comparing it to several numerical examples of traditional finite element methods.

The Production of B4C Particle-Reinforced Composite Materials with the Powder Metallurgy Technique and Examination of Their Bending Strength

In this study, AA2024 aluminum alloy was selected as the matrix material, while B4C was selected as the reinforcement material, and particle-reinforced Al-matrix composite materials were produced using the powder metallurgy method. B4C ceramic powders were added to the AA2024 matrix. Examinations were made to determine the effects of different reinforcement particle ratios and sintering temperatures on the mechanical properties of the composite materials that were produced. The powders were homogeneously mixed and compressed in a metal mold at room temperature and a pressure of 525 MPa under a uniaxial press. The raw specimens that were obtained were sintered for 45 minutes at different temperatures. The produced composite materials were subjected to three-point bending tests and hardness measurements. Optical microscopy analysis was carried out for characterization. The results allowed us to draw a conclusion on how the reinforcement material in the produced specimens affected composite properties.

Surrogate modeling of the effective elastic properties of spherical particle-reinforced composite materials

This paper focuses on the development of a surrogate model to predict the macroscopic elastic properties of polymer composites doped with spherical particles. To this aim, a polynomial chaos expansion based Kriging metamodeling technique has been developed. The training experimental design is constructed through a dataset of numerical representative volume elements (RVEs) considering randomly dispersed spherical particles. The RVEs are discretized using finite elements, and the effective elastic properties are obtained by implementing periodic boundary conditions. Parametric analyses are reported to assess the convergence of the scale of the RVE and the mesh density. The accuracy of the proposed metamodelling approach to bypass the computationally expensive numerical homogenization has been evaluated through different metrics. Overall, the presented results evidence the efficiency of the proposed surrogate modelling, enabling the implementation of computationally intensive techniques such as material optimization.

Comparative research on tension-compression mechanical properties of the azide propellant

While the azide propellant is a typical particle-reinforced composite material, its mechanical properties are quite different under two different loads of tension and compression. In order to study the possible relationship between the tension and compression mechanical properties of the propellant, so as to further study the loading mechanism of the propellant, this paper carried out constant-rate tension and constant-rate compression tests of the azide propellant and measured the stress-strain curves in different loading case for follow-up comparative study. The mechanical properties of the propellant under different loading rates were analyzed quantitatively, and the differences between the tension and compression stresses of the propellant at different strain rates were quantitatively analyzed, and the change rules of tension-compression mechanical properties of the azide propellant were obtained. The research results can provide the basis for the application analysis of the azide propellant in the engine, and the research method can provide a reference for the tension-compression comparative study of other types of propellants.

A new model for thermal conductivity of “continuous matrix / dispersed and separated 3D-particles” type composite materials and its application to WC-M (M = Co, Ag) systems

In the present work a new thermal conductivity model is developed for two-phase composite materials, which are consisted of a continuous matrix and dispersed 3D-particles separated from each other by the matrix as a function of grain size and volume ratio of the dispersed particles at different temperatures. The model is applied to reproduce experimental thermal conductivity values of cemented carbide systems WC-Co and WC-Ag. Good agreement was found between measured thermal conductivity data originating from both this work and recent literature and the calculated ones only using semi-empirical parameters for the interfacial thermal resistance (ITR) values at WC/Co, WC/Ag and WC/WC interfaces as a function of temperature. Additionally, the temperature and grain size dependence of the thermal conductivity for WC is established for the first time. The model works well for the case when the matrix (Ag) has a higher thermal conductivity compared to that of the WC particles and also for the case when the matrix (Co) has a lower thermal conductivity compared to that of the WC particles. The new model forms a physically sound basis for further development / materials design of cemented carbides and particle-reinforced composite materials.

Study on formation mechanism of edge defects of high-volume fraction SiCp/Al composites by longitudinal-torsional ultrasonic vibration-assisted milling

SiCp/Al composites are a kind of particle-reinforced composite material, which has been widely used in various fields due to its excellent performance. However, during the machining, the damage and failure of the SiC particles, the aluminum matrix, and the interface phase will cause many surface and edge defects. These defects will seriously affect the application of SiCp/Al composites. In this paper, a finite element model of randomly distributed multi-cell SiCp/Al composites with longitudinal-torsional ultrasonic vibration-assisted milling was established to analyze the formation mechanism of edge defects of the material. The simulation results showed that the main reason for the formation of edge defects was that the interface, SiC particles, and the Al matrix will produce cracks during machining, and these cracks will propagate and cause particle breakage, matrix tearing, and edge gaps. According to different machined parameters, the ultrasonic vibration-assisted milling experiment was carried out. The test results showed that the actual processed workpiece does have defects such as edge gaps. The depth of cut and the feed per tooth had a serious influence on the edge defect value, while the cutting speed had a small effect. Moreover, under the condition of applying appropriate ultrasonic amplitude, the phenomenon of edge defects and the surface quality were significantly improved. Therefore, the application of ultrasonic vibration-assisted milling can improve the surface and edge quality of SiCp/Al composites.

Fiber- and Particle-Reinforced Composite Materials With the Gurtin–Murdoch and Steigmann–Ogden Surface Energy Endowed Interfaces

Abstract Modern advances in material science and surface chemistry lead to creation of composite materials with enhanced mechanical, thermal, and other properties. It is now widely accepted that the enhancements are achieved due to drastic reduction in sizes of some phases of composite structures. This leads to increase in surface to volume ratios, which makes surface- or interface-related effects to be more significant. For better understanding of these phenomena, the investigators turned their attention to various theories of material surfaces. This paper is a review of two most prominent theories of that kind, the Gurtin–Murdoch and Steigmann–Ogden theories. Here, we provide comprehensive review of relevant literature, summarize the current state of knowledge, and present several new results.

Aggregate particle size interrelations and case study in concrete using white ordinary Portland cement

The size distribution, the gradation and the type of aggregates are factors of great relevance for the design of mixtures in concrete and construction materials in general since these allow us to obtain information on the voids contents, module fineness, bulk density, and mechanical performance that certain aggregate mixtures will present. In the present work, different mixtures of aggregates were made using three types of raw materials: fine sand, coarse sand, and 3/8” aggregate, for which their mineralogical composition was evaluated using X-ray diffraction, the chemical composition using X-ray fluorescence, and its macroscopic structure using optical microscopy. Sixty-six mixture formulations were made, to which variables such as fineness modulus, particle size distribution, void content, and density were evaluated. These data were represented in ternary diagrams. From the gradation studies carried out, six formulations were selected based on the type of aggregate used and the content of voids. With this selection, concrete specimens were made, which were subjected to compression tests, finding that the mixture A 22, with 17 % of voids generated a compressive strength of 22 MPa. The results obtained can be used not only in applications such as zero-set concrete, concrete block masonry, or regular concretes, but also in asphalt pavements, ceramic materials obtained by sintering, and particle-reinforced composite materials.

Simulation Research on Vibration Cutting Mechanism of Metal Matrix Composites

Particle-reinforced metal composite materials have been widely used in the industry due to their excellent abrasion resistance and high strength, but they are typical hard-to-machine materials. A finite element model of the material matrix and enhanced particles have been established by the parametric modeling in this paper. Different from the previous development process, the particle is randomly distributed in this study, so the particle distribution has been better simulated than ever. The study shows that vibration-cutting particle-reinforced composites have reduced the phenomenon of particle suspension on the machined surface compared to conventional cutting, and the high-elastic-modulus reinforcing particles have been subjected to high stress, and the matrix between the particles have acted as a stress-transmitting “channel”. When the particle’s diameter is 20μm and the volume fraction is 30%, there is a stress transmitting channel in a certain range away from the tool tip. When the cutter contacts the particles, the vibration cutting will cause the initial crack near the particle, which cut off part of the stress transmitting channels, make the stress concentrated on the tool tip and lead to the material easier to remove.

SHPB test analysis and a constitutive model for frozen soil under multiaxial loading

A split Hopkinson pressure bar is adopted to test the dynamic mechanical behavior of frozen soil at different temperatures and high strain rates. An aluminum sleeve is used as a passive confining pressure device. Comparing the results of this test with those under the uniaxial state shows that besides the temperature and strain rate effects, frozen soil exhibits obvious stress strengthening characteristics. In addition, the failure mode is viscoplastic instead of brittle. If frozen soil is regarded as a particle-reinforced composite material, then the debonding damage of ice particles and rate-dependent damage of soil matrix are taken into account. Based on this, a dynamic constitutive model of frozen soil under a multiaxial state is proposed. The theoretical results of the model agree well with the experimental results, verifying the rationality and applicability of the model.

Toward high-accuracy and high-applicability of a practical model to predict effective thermal conductivity of particle-reinforced composites

A particle-reinforced composite material is a matrix with thermally conductive particles that has a diverse range of applications from electronics to energy harvesting/storage systems. In the engineering design of a particle-reinforced composite material for application, it is crucial to accurately and practically predict its effective thermal conductivity. Here, we report the development of a simple analytical model for predictions with improved accuracy and applicability. Comprehensive evaluation of existing models was first conducted to clarify their limitations in prediction accuracy and applicability to various experimental conditions. To overcome the challenges of the existing models, our new model was derived to consider the effect of shape, particle aggregation, and mutual interaction of particles on effective thermal conductivity. Lattice Boltzmann simulations were conducted to obtain a quasi-universal coefficient representing interactions of particles, whereas a shape coefficient characterizing microstructures of aggregated particles was obtained from experimental data available from literature. As a result, our model prediction outperformed the existing models in its prediction accuracy, and it could be applicable to any experimental circumstances where previous model predictions are inappropriate to use.

A new three-dimensional parametric FVDAM for investigating the effective elastic moduli of particle-reinforced composites with interphase

ABSTRACTIn recent years, the micromechanics model plays an important role in investigating the mechanical properties for particle-reinforced composite (PRC) materials. In this article, through discretizing the representative volume element (RVE) with eight-node hexahedral isoparametric elements, as well as expressing the higher-order displacement functions as the function of surface-averaged displacements for the subcell, a new parametric micromechanical model is presented to investigate the elastic constant variations of the three-dimensional PRC. For validating the proposed method, the finite element method (FEM) is employed for solving the PRC without consideration of interphase. The calculated results by employing the FEM show a good consistency with the proposed micromechanical method. Furthermore, interphase thickness, as well as interphase modulus effect on elastic constant are further predicted and discussed.

Elastohydrodynamic lubrication in point contact on the surfaces of particle-reinforced composite

Appreciable friction and serious wear are common challenges in the operation of advanced manufacturing equipment, and friction pairs may be susceptible to damage even with oil lubrication when point contact exists. In this study, a type of particle-reinforced composite material is introduced for one of the components of a heavy-load contact pair, and the performance improvement of elastohydrodynamic lubrication (EHL) is analyzed considering the rheological properties of non-Newtonian fluids. The Ree–Eyring EHL model is used considering the surface of the particle-reinforced composite, in which the film thickness includes the particle-induced elastic deformation. The problem of inclusions with different eigenstrains is solved by using Galerkin vectors. The influences of particle properties, size, burial depth, and interparticle distance on point-contact EHL are investigated. Furthermore, using several cases, the structural parameters of the particles in the composites are optimized, and an appropriate parameter range is obtained with the goal of reducing friction. Finally, the results for the EHL traction coefficient demonstrate that appropriate particle properties, size, burial depth, and interparticle distance can effectively reduce the traction coefficient in heavy-load contact.

Determination of a homogeneity factor for composite materials by a microstructural image analysis method.

The physical properties of particle-reinforced composite materials are highly affected by the distribution of particles within a matrix material. In this study, a microstructural image analysis method with a new distribution index for quantifying the degree of distribution in composite materials was developed. The free-path spacing between particles was measured to calculate the distribution (D) index based on the coefficient of variation. The proposed method was applied to six digitally created reference patterns as representative binary composite microstructures and three actual ceramic-matrix composites, respectively. It is found that the D index increased from 0.00 to 0.67 depending on the degree of distribution or homogeneity level based on the reference patterns. The homogeneity levels for the binary composites are then classified from a perfect (maximum) to very low level (minimum) based on increasing D index values, where a high D index presents a poorer distribution. The results obtained for reference patterns and metal silicide-refractory oxide composite microstructures indicate that the proposed method is a useful tool to quantify the degree of distribution with high accuracy, and can be efficiently used for different types of composite microstructures.

Friction-stir welding of aluminum alloy with an iron-based metal as reinforcing material

Abstract The fabrication of a durable and usable aluminum matrix composite poses a challenge because it is hard to obtain defect-free welds by using conventional fusion welding methods. The development of friction-stir welding (FSW) provides improved microstructure modification. As there are no melting problems associated with it, liquid-solid reactions are eliminated. The objective of this study was to attempt FSW of an AA6061 alloy reinforced with an iron-based metal and to determine the properties of the joints. The effects of FSW parameters, especially the tool rotation speed, are presented first. Then, the application of the technique in manufacturing and microstructure modification of particle-reinforced composite materials is discussed. Finally, interfacial microstructural changes and the associated mechanical properties are evaluated.

Crack propagation in non-homogenous materials: Evaluation of mixed-mode SIFs, T-stress and kinking angle using a variant of EFG Method

A new variant of the Element-Free Galerkin (EFG) method, that combines the diffraction method, to characterize the crack tip solution, and the Heaviside enrichment function for representing discontinuity due to a crack, has been used to model crack propagation through non-homogenous materials. In the case of interface crack propagation, the kink angle is predicted by applying the maximum tangential principal stress (MTPS) criterion in conjunction with consideration of the energy release rate (ERR). The MTPS criterion is applied to the crack tip stress field described by both the stress intensity factor (SIF) and the T-stress, which are extracted using the interaction integral method. The proposed EFG method has been developed and applied for 2D case studies involving a crack in an orthotropic material, crack along an interface and a crack terminating at a bi-material interface, under mechanical or thermal loading; this is done to demonstrate the advantages and efficiency of the proposed methodology. The computed SIFs, T-stress and the predicted interface crack kink angles are compared with existing results in the literature and are found to be in good agreement. An example of crack growth through a particle-reinforced composite materials, which may involve crack meandering around the particle, is reported.

Effects of cutting parameters on drilling performance of carbon black–reinforced polymer composite

Polymer composite materials can be produced by reinforcing carbon black, carbon fiber, graphite, graphene, metals and metal oxides, nanotubes, and so on. These types of composite materials can be employed in applications demanding electrical conductivity besides high specific strength and stiffness properties of polymer materials. In the literature, there is a lack of knowledge on the examination of drilling of particle-reinforced composite materials. In this study, drilling of pure polypropylene and carbon black–reinforced polypropylene composite material was investigated at different drill point angles, cutting speeds, and feeds. The cutting temperature of drill point and surface roughness of holes were examined. The experimental studies were designed by L27 full-factorial design, and analysis of variance statistical method was performed. According to the results, cutting temperature increased and surface roughness decreased with the increase in the cutting speed and feed and decrease in the drill point angle.

A Dynamic Micromechanical Constitutive Model for Frozen Soil under Impact Loading

By taking the frozen soil as a particle-reinforced composite material which consists of clay soil (i.e., the matrix) and ice particles, a micromechanical constitutive model is established to describe the dynamic compressive deformation of frozen soil. The proposed model is constructed by referring to the debonding damage theory of composite materials, and addresses the effects of strain rate and temperature on the dynamic compressive deformation of frozen soil. The proposed model is verified through comparison of the predictions with the corresponding dynamic experimental data of frozen soil obtained from the split Hopkinson pressure bar (SHPB) tests at different high strain rates and temperatures. It is shown that the predictions agree well with the experimental results.