Effect Of Reinforcement Particle Size Research Articles

Effect of reinforcement particle size on the corrosion and mechanical properties of spark plasma sintered aluminium matrix composites.

In this study, the effects of different sizes of reinforcing particles on the corrosion behaviour and mechanical properties of aluminium (Al)-based composites produced by spark plasma sintering (SPS) are analysed. In the study, the effects of SPS parameters, including electrical power, applied pressure and sintering temperature, on the consolidation process and microstructure evolution of the composite are closely investigated. The results reveal a nuanced relationship between the sintering conditions and the properties of the particles, which in turn determine the sintering dynamics and the formation of the microstructural features. The evaluation of mechanical properties indicates a remarkable influence of particle size distribution on the hardness of the composites, showing an initial improvement with the introduction of nanoparticles, followed by a slight decrease as the balance between nano- and micron-sized Al2O3 particles shifts. A scanning electron microscopy (SEM) study demonstrates the influence of particle dimensions on the change of grain boundaries and the spatial arrangement of the composite matrix. Electrochemical experiments in a 0.1M NaCl solution show a consistent corrosion potential (Ecorr) across all samples, while the current densities associated with corrosion (icorr) show considerable variation. The presence of nano-sized Al2O3 particles was found to increase corrosion resistance, in contrast to the detrimental effects observed with larger microparticles. In particular, composites with a bimodal distribution of particle sizes showed a 3.5-fold increase in corrosion resistance compared to pure Al. The specific Al-2n8mAl2O3 composite that exhibited active electrochemical properties at elevated potentials without a defined passivation range emphasises the significant role of particle size. This study draws attention to bimodal microstructures as a promising route to achieving uniformity and improved corrosion resistance in Al matrix composites, while pointing to the need for further research to fully elucidate the operative mechanisms.

The effect of reinforcement particle size on the mechanical and fracture properties of glass matrix composites

The strength and toughness of sealing glass are currently unable to meet increasingly severe application conditions, and composites are an effective way to solve this problem. The size of reinforcement particles significantly affects the material properties, while the underlying mechanism still eludes deeper understanding. In this paper, the influence of the embedded alumina size is investigated from the perspectives of mechanical and fracture properties by mechanical tests, fracture toughness tests and the finite element method. The results of the experiment and simulation indicate that the fracture energy is mainly consumed by interface debonding and particle breakage, and the former consumes more energy. Materials with large particles have better mechanical properties, while those with small particles have better fracture properties. This difference could be ascribed to the curvature of the particles rather than the size. Therefore, an ideal reinforcement particle shape with both mechanical and fracture advantages is proposed. The results shed light on the nature of particle enhancement and point out a new direction for the design of sealing glass composites.

Machinability analysis and multi-response optimization using NGSA-II algorithm for particle reinforced aluminum based metal matrix composites

In this study the effects of reinforcement particle size and cutting parameters on machining performance variables like cutting force, maximum tool-chip interface temperature and surface roughness of the machined surface have been investigated while machining Aluminum based metal matrix composites (MMCs). MMC bars with silicon carbide reinforcement having 10 % volume fraction and particle sizes of 5 μm, 10 μm and 15 μm are machined with polycrystalline diamond (PCD) inserts. Experiments are performed using central composite design (CCD) having four parameters with three levels. Response surfaces for each performance variables are generated using polynomial models. Single variable and interaction effects have been investigated using principal component analysis and 3D response charts. Multi-response optimization has been performed to minimize surface roughness and maximum tool-chip interface temperature using non-dominated sorting genetic algorithm II (NSGA-II). In addition, constraints have been applied to the optimization search to filter design points with high cutting forces and low material removal rate. Most of the optimal solutions are found to be with moderate cutting speeds, low feed rate and low depth of cuts.

Effect of reinforcement particle size on quasistatic and dynamic mechanical properties of Al-Al2O3 composites

Herein, high-energy ball milling and hot pressing are employed to synthesize Al-15 vol.% μm Al2O3 (Al-MMC) and Al-15 vol.% nm Al2O3 (Al-MMNC) composites and the influence of reinforcement particle size (3 μm and 50 nm) on mechanical properties has been systematically studied. The as-prepared Al-MMNC samples rendered superior mechanical properties than Al-MMC and pure Al, with an improved yield strength and ultimate strength of 610 MPa and 784 MPa under quasistatic compression, respectively. Moreover, the flow stress of Al-MMC and Al-MMNC increased with increasing strain rate, and Al-MMNC exhibited higher flow stress than Al-MMC due to the smaller particle size. It is worth noting that the ultimate strength of Al-MMNC reached 963 MPa under the loading rate of 2200 s−1. Moreover, unlike previously reported Al-based nanocomposites, Al-MMNC exhibited strain hardening and strong strain rate sensitivity, which is highly desirable for engineering applications. Lastly, the ex-situ SEM analysis revealed the presence of microcracks and dimples on the fractured surface of Al-MMNC, which led to the ductile fracture mode under quasistatic compression. Moreover, the adiabatic shear under high strain rate loading has also been observed in Al-MMNC, but the high volume fraction nanoparticles inhibit adiabatic shear band development, and result in strain hardening and strong strain rate sensitivity.

Sinterability and electrochemical behavior of Al2O3 dispersed Al 7150 alloy composite prepared by high energy ball milling

Particulate Al2O3 (with varying particle size and volume fraction) dispersed Al 7150 alloy composites were synthesized by ball milling followed by cold uniaxial compaction and sintering. The effect of reinforcement particle size on the sinterability and electrochemical behavior of the composites is demonstrated in this study. The sinterability of the composites increased with the reduction in particulate’s size, which enhanced, easy filling up of finer pores and particle induced precipitation. The Vickers microhardness test results indicate an enhancement of VHN (Vickers Hardness Number) values with the decreasing particle size and increasing vol% of Al2O3. Potentiodynamic electrochemical polarization studies on the Al 7150 alloy and Al 7150 alloy + x vol% Al2O3 (x = 5, 10, 20) composites in 3.5 wt% sodium chloride solution indicated that the increase in Al2O3 content caused the shifting of corrosion potential (Ecorr) towards the noble direction. The addition of Al2O3 content also increased the corrosion current density (icorr) of the composites. Optical images of the corroded surfaces of the Al 7150 alloy and its composites revealed the presence of general and pitting corrosion. HRTEM (High-Resolution Transmission Electron Microscopy) analysis revealed the formation of η′ phase and η precipitate phases. The AFM (Atomic Force Microscopy) analysis of the corroded surface of Al 7150 alloy sample showed severe damage due to pitting corrosion with a surface roughness of 0.37 μm and height scale of 1 μm (in 3D view), while the Al 7150 alloy + 10 vol% (as-received) Al2O3 composite specimen, showed a surface roughness of 0.255 μm and a height scale of 0.8 μm (in 3D view). Nevertheless, the Al 7150 alloy + 10 vol% 20 h milled Al2O3 composite, exhibited a reduced surface roughness of only 26.069 nm (in 2D view) and height scale of 150 nm (in 3D view). Thus the AFM analysis demonstrated that the Al 7150 + 10 vol% of Al2O3 (20 h milled) composite specimens exhibited superior resistance to pitting corrosion than the other composite specimens.

The effect of reinforcement particle size on the properties of Cu-Al2O3 composites

abstractThe main aim of this paper was to investigate the effect of reinforcement particle size on the properties of Cu-Al2O3 composites. The starting materials for obtaining the composites were commercial powders: Cu and Al2O3. Experiments were performed using specimens containing 2.5, 5, 7.5 and 10 % of alumina. The average particle sizes of alumina were 3.5, 22.5, and 65 μm. Before the sintering process, single pressing was performed with a hydraulic press at a compaction pressure of 620 MPa. The obtained sinters were subjected to the compaction process at a pressure of 620 MPa, and then again sintered at 900 °C for 60 minutes. The sintering process was carried out for 60 minutes at a temperature of 900 °C. The sintered compacts were subjected to the following tests: measurement of density, hardness and electrical conductivity. Observations of the microstructure on metallographic specimens made from the sintered samples were also performed using a scanning electron microscope (SEM). The density of all the composites increased when the particle size of alumina was reduced. Higher hardness were observed in samples containing finer Al2O3 particles. The electrical conductivity of the fabricated composites increased with the reduction of the alumina particle size.

Processing and strengthening mechanisms of boron-carbide-reinforced aluminum matrix composites

Boron-carbide-reinforced aluminum matrix composites are widely used as various function materials. This paper aims at reviewing theoretical and experimental background related to boron-carbide-reinforced aluminum matrix composites. The powder milling processing, solid sintering, thermo-mechanical processing and the effects of reinforcement particle size on the microstructure and morphology evolution of the aluminum matrix composites are reviewed. The formation of interface between boron carbide and matrix and strengthening mechanisms of the boron-carbide-reinforced aluminum matrix composites are discussed.

Effect of Reinforcement Particle Size and Weight Fraction on the Mechanical Properties of SiC Particle Reinforced Al Metal Matrix Composites

The production of engineering materials that possess low density and distinguished mechanical properties has been one of the most stimulating issues in both academic and industry in the last three decades, which caused a shift in research from monolithic to composite materials. For this reason aluminium matrix composites were widely manufactured and used in many aerospace and automobile industries. In this work, the effect of different processing parameters such as particle size and percentage of reinforcement on the tensile properties of Al-10Sb/SiC composite was investigated. Stir casting technique was used to fabricate the composites. The results showed a significant improvement in the yield and ultimate tensile strengths of the composite with increasing the SiC content and/or decreasing the particle size of the reinforcement. The yield and ultimate tensile strengths of the Al composites produced with the finest particle size of 115 µm and at 9% wt. Sic were the highest among all composites. On the other hand the composite exhibited impaired ductility compared with the unreinforced Al alloy.

Influence of particle size of the dispersoid on compressibility and sinterability of TiO2 dispersed Al 7075 alloy composites prepared by mechanical milling

Particulate TiO2 (with varying particle size produced by mechanical milling) dispersed AA7075 composites are synthesised by short duration milling (10min) followed by room temperature unidirectional compaction (with varying pressure) and sintering. Apparent and relative density of the alloy powder and composites are measured. The effect of reinforcement particle size on the compressibility behaviour of the composites is demonstrated. Mechanically milled (for 25h) alloy powder shows lower relative density than coarse alloy powder. In addition, compressibility of the alloy composites decreases with decreasing particle size of the reinforcement. In contrast, the sinterability of the composites increases with decreasing dispersoid’s size due to easy filling up of finer pores and particle induced precipitation.

Investigation on the Effect of Reinforcement Particle Size on the Mechanical Properties of the Cold Sprayed Ni-Ni3Al Composites

In the present study, cold spraying technique was used to fabricate a metal matrix composite (MMC) that consists of Ni matrix and 20 vol.% Ni3Al particles at two different particle sizes as reinforcement. This study intends to investigate the effect of reinforcement particle size on microstructural and mechanical properties of cold sprayed MMCs. Two different Ni3Al powders with nominal particle size of −45 to +5 and +45 to 100 μm were used as reinforcement in this study. Cold sprayed Ni-Ni3Al samples were subjected to the microstructural observation and characterization prior to any mechanical testing. Then, samples were tested using nano-indentation, Knoop hardness, Vickers hardness, and Resonance frequency to evaluate their mechanical properties. No significant changes were observed in microstructural characteristics due to different particle sizes. The results obtained from a variety of mechanical testings indicated that the increasing reinforcement particle size resulted in the slight reduction of mechanical properties such as elastic modulus and hardness in cold sprayed MMCs. The mechanical interlock between deposited particles defines the bonding strength in cold sprayed samples. Small size particles have a higher velocity and impact resulting in stronger interlock between deformed particles.

Effect of Reinforcement Particle Size on Fabrication and Properties of Composite Coatings

In this work, three nickel-cobalt-phosphorus composite coatings co-deposited with particles of silicon carbide of three different sizes (40, 200, and 800 nm) were prepared on aluminum alloys using electroless deposition. The fabrication process of composites has been discussed, and the effect of the particle size of silicon carbide on microhardness and corrosion resistance of composites has been studied. The morphology, composition, microstructure, microhardness, and corrosion resistance of deposits were characterized by scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, Vickers hardometer, and electrochemical workstation, respectively. The results reveal that the particle size has not much effect on the deposition rate of coatings; however, the coating codeposited with smaller particles has greater incorporation amount of particles in number density, less porosity, and finer grains. Furthermore, the incorporation of smaller particles leads to higher hardness and better corrosion resistance of coatings.

Effect of weight percentage and particle size of B4C reinforcement on physical and mechanical properties of powder metallurgy Al2024-B4C composites

In this study, Al2024-B4C composites containing 0, 5, 10 and 20 wt% of B4C particles with two different particle sizes (d50=49 μm and d50=5 μm) as reinforcement material were produced by a mechanical alloying method. Two new particle distribution models based on the size of reinforcement materials was developed. The microstructure of the Al2024-B4C composites was investigated using a scanning electron microscope. The effects of reinforcement particle size and weight percentage (wt%) on the physical and mechanical properties of the Al2024-B4C composites were determined by measuring the density, hardness and tensile strength values. The results showed that more homogenous dispersion of B4C powders was obtained in the Al2024 matrix using the mechanical alloying technique according to the conventional powder metallurgy method. Measurement of the density and hardness properties of the composites showed that density values decreased and hardness values increased with an increase in the weight fraction of reinforcement. Moreover, it was found that the effect of reinforcement size and reinforcement content (wt%) on the homogeneous distribution of B4C particles is as important as the effect of milling time.

Effect of particle size and ratio of B4C reinforcement on properties and morphology of nanocrystalline Al2024-B4C composite powders

In this study, two new milling models based on the size of reinforcement materials were developed. Al2024-B4C nanostructured composite powders containing 0, 5, 10 and 20 weight percentage (wt.%) of B4C particles with two different particle sizes (d50 = 49 μm and d50 = 5 μm) as reinforcement material were produced by mechanical milling. The milling was carried out in a planetary ball mill for 10 h with a rotating speed of 400 rpm and ball to powder ratio of 10:1. The effects of reinforcement particle size and weight percentage on fracture and plastic deformation behavior of composite powders were investigated. The particle size, morphology and microhardness were used as the main criterions. The structural and mechanical evolutions of the mechanically milled powders were investigated using a scanning electron microscopy, a laser particle-size analyzer, an X-ray diffractometry and a microhardness tester. It was found that milling time as well as reinforcement size and reinforcement content were strongly affecting the particle size and microhardness of composite powders. The results showed that the coarse B4C particles accelerated the milling process due to cutting effect, while fine B4C particles accelerated the milling process due to embedding effect.

Effect of reinforcement particle size on microstructure and mechanical properties of AlZnMgCu/AlN nano-composites produced using mechanical alloying

Abstract In this study, an attempt has been made to determine the effect of an AlN reinforcement size on properties of aluminum alloy matrix composites produced via mechanical alloying/uniaxial hot pressing. Composite samples were prepared using pre-alloyed AA7475 powder with 10 wt.% of AlN additions of differing average particle sizes:

Effect of volume fraction and particle size of alumina reinforcement on compaction and densification behavior of Al–Al2O3 nanocomposites

Al–Al2O3 nanostructured composite powders containing 1, 3 and 7 percent volume fraction (vf%) of submicron/nanometeric alumina particles as reinforcement phase were produced by high energy milling. The powders were consolidated by a uniaxial cold press and sintered for various durations of time. Effects of reinforcement particle size and volume fraction on compaction and sintering behavior of nanocomposite powders were investigated considering relative density as the main criterion. It was found that the nanometeric alumina particles had a more hindering effect on densification of the composite powders as compared to the submicron particles. The hindering effect was found to be aggravated by higher volume fractions of the reinforcement particles.

Analysis of the compaction behavior of Al–SiC nanocomposites using linear and non-linear compaction equations

The compressibility behavior of Al–SiC nanocomposite powders was examined and the density-pressure data were analyzed by linear and non-linear compaction equations. SiC particles with an average size of 50 nm were mixed with gas-atomized aluminum powder (40 μm average size) at different volume fractions (up to 20 vol%) and compacted in a rigid die at various pressures. In order to highlight the effect of reinforcement particle size, the compressibility of micrometric SiC particles of two sizes (1 and 40 μm) was also examined. Analysis of the compressibility data indicated hindering effect of the hard ceramic particles on the plastic deformability of soft aluminum matrix, particularly at high volume fractions. More pronounced effect on the yield pressure was obtained for the nanometric particles compared with the micrometric ones. Nevertheless, better particles rearrangement was taken place when the ultrafine SiC particles were utilized. In light of the experimental and theoretical analysis, the densification mechanism of aluminum matrix composites and the effect of reinforcement particle size and volume fraction are discussed.

Effect of Reinforcement Particle Size on the Tribological Properties of Nano-Diamond Filled Polytetrafluoroethylene Based Coating

The tribological properties of PTFE composite coatings reinforced by nano-diamonds were investigated. Mechanical particle size reduction and dispersion of nano-diamond aggregates were performed by milling with ceramic beads in an organic solvent. Particle size was controlled by the milling time. Pastes comprising a PTFE solution mixed with nano-diamond having various sizes were coated on the aluminum substrate. Ball-on-plate type wear test was performed to investigate the friction and wear behavior. The results indicated that the addition of nano-diamonds effectively improved tribological performance of the PTFE coating. The reduction in nano-diamond sizes were not always improved the wear resistance of PTFE coating. This unexpected behavior was explained by observation on the worn surfaces and wear debris.

Synthesis and properties of soy hull‐reinforced biocomposites from conjugated soybean oil

AbstractThe tensile and flexural properties of new thermosetting composites made by the free radical polymerization of a conjugated soybean oil (CSO)‐based resin reinforced with soy hulls have been determined for various resin compositions. The effects of reinforcement particle size and filler/resin ratio have been assessed. The thermal stability of the new materials has been determined by thermogravimetric analysis and the wt % of oil incorporation has been calculated after Soxhlet extraction (the extracts have been identified by 1H‐NMR spectroscopy). The resin consists initially of 50 wt % CSO and varying amounts of divinylbenzene (DVB; 5–15 wt %), dicyclopentadiene (DCPD; 0–10 wt %), and n‐butyl methacrylate (BMA; 25–35 wt %). Two soy hull particle sizes have been tested (<177 and <425 μm) and two different filler/resin ratios have been compared (50 : 50 and 60 : 40). An appropriate cure sequence has been established by differential scanning calorimetry (DSC) analysis. The results show a decrease in the properties whenever DVB or BMA is substituted by DCPD. Also, larger particle sizes and higher filler/resin ratios are found to have a negative effect on the tensile properties of the new materials. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Pressure-less and current-activated pressure-assisted sintering of titanium dual matrix composites: Effect of reinforcement particle size

This paper investigates a microstructural design that can allow the tailorability of the properties of titanium–titanium boride composites. A powder processing sequence is used to allow the in situ growth of TiB whiskers in localized regions (of controlled size) of the microstructure leaving predominantly ductile titanium in between these reinforced regions. Both current-activated pressure-assisted sintering (CAPAS) and pressure-less sintering were used as high temperature consolidation processes for the powders. Superior composites in terms of consolidation, hardness and reaction completion were produced using CAPAS as opposed to pressure-less sintering. For CAPAS processed materials, the size of the reinforced regions had a significant effect on the hardness of the composites, with values ranging from 652 to 777 VHN (a 19% difference).

Analysis of the effect of reinforcement particles on the compressibility of Al–SiC composite powders using a neural network model

A neural network (ANN) model was developed to predict the densification of composite powders in a rigid die under uniaxial compaction. Al–SiC powder mixtures with various reinforcement volume fractions (0–30%) and particle sizes (50 nm to 40 μm) were prepared and their compressibility was studied in a wide range of compaction pressure up to 400 MPa. The experimental results were used to train a back propagation (BP) learning algorithm with two hidden layers. A sigmoid transfer function was developed and found to be suitable for analyzing the compressibility of composite powders with the least error. The trained model was used to study the effect of reinforcement particle size and volume fraction on the densification of Al–SiC composite powders. The outcomes of the ANN model are analyzed based on the mechanisms of densification, i.e., particle rearrangement and plastic deformation. The proper condition of compaction for achieving the highest density by tailoring the reinforcement particle size and volume fraction dependent on the compacting pressure is presented.