Particle-reinforced Aluminum Research Articles

Preparation and Forming Technology of Particle Reinforced Aluminum Matrix Composites

This paper introduces the performance and preparation technology and forming technology of particle reinforcedaluminum matrix composites. The application status of particle reinforced aluminum matrix composites is illustrated,and its development prospect is pointed out.

Experimental study on SiCp/Al composites with different volume fractions in high-speed milling with PCD tools

The single-tooth milling cutter with diamond grain size of 5 μm was used for high-speed milling silicon carbide particle-reinforced aluminum matrix (SiCp/Al) composites with larger SiC particles and different volume fractions. The volume fractions of SiC particles were 15, 25, 30, and 56%, respectively. The effects of volume fraction of SiC particles on tool wear morphology and wear resistance were analyzed in this paper. The effects on cutting force and machined surface roughness were also studied. The results show that it has little effect of volume fraction of SiC particles on the tool wear morphology, but it has a great effect on the variety of wear amount and wear rate. When SiCp/Al composites wit h low volume fraction are machined, the tool wear amount of polycrystalline diamond (PCD) tools is small and increase slowly. When workpiece with high volume fraction is machined, the tool wear amount increases significantly with the increase of cutting distance. The measured cutting force changes differently when SiCp/Al composites with different volume fractions are machined at high speed. In the initial cutting period, there is little influence of volume fraction on the cutting force component. However, the influence becomes significant with the increase of cutting distance. The machined surface roughness with different volume fractions is larger and has a certain fluctuation in the initial cutting stage. When the cutting distance increases to a certain extent, the surface roughness decreases and tends to be steady. All in all, the surface roughness is larger when the volume fraction of SiC particles is higher.

Friction Stir Processing of Copper-Coated SiC Particulate-Reinforced Aluminum Matrix Composite.

In the present work, we proposed a novel friction stir processing (FSP) to produce a locally reinforced aluminum matrix composite (AMC) by stirring copper-coated SiC particulate reinforcement into Al6061 alloy matrix. Electroless-plating process was applied to deposit the copper surface coating on the SiC particulate reinforcement for the purpose of improving the interfacial adhesion between SiC particles and Al matrix. The core-shell SiC structure provides a layer for the atomic diffusion between aluminum and copper to enhance the cohesion between reinforcing particles and matrix on one hand, the dispersion of fine copper in the Al matrix during FSP provides further dispersive strengthening and solid solution strengthening, on the other hand. Hardness distribution and tensile results across the stir zone validated the novel concept in improving the mechanical properties of AMC that was realized via FSP. Optical microscope (OM) and Transmission Electron Microscopy (TEM) investigations were conducted to investigate the microstructure. Energy dispersive spectrometer (EDS), electron probe micro-analyzer (EPMA), and X-ray diffraction (XRD) were explored to analyze the atomic inter-diffusion and the formation of intermetallic at interface. The possible strengthening mechanisms of the AMC containing Cu-coated SiC particulate reinforcement were interpreted. The concept of strengthening developed in this work may open a new way of fabricating of particulate reinforced metal matrix composites.

Particle-Reinforced Aluminum Matrix Composites (AMCs)—Selected Results of an Integrated Technology, User, and Market Analysis and Forecast

The research and development of new materials such as particle-reinforced aluminum matrix composites (AMCs) will only result in a successful innovation if these materials show significant advantages not only from a technological, but also from an economic point of view. Against this background, in the Collaborative Research Center SFB 692, the concept of an integrated technology, user, and market analysis and forecast has been developed as a means for assessing the technological and commercial potential of new materials in early life cycle stages. After briefly describing this concept, it is applied to AMCs and the potential field of manufacturing aircraft components. Results show not only technological advances, but also considerable economic potential—the latter one primarily resulting from the possible weight reduction being enabled by the increased yield strength of the new material.

Atomic-level study on mechanical properties and strengthening mechanisms of Al/SiC nano-composites

Molecular dynamics (MD) models for the study on the mechanical properties of β-SiC particles-reinforced aluminum matrix nano-composites (Al/SiC nano-composites) are established. The nano-composites in the model are fabricated by a powder metallurgy (P/M) process, followed by a hot isostatic pressing and then annealing to room temperature. The fabricated nano-composites have dense and even distributions of reinforced particles. Then representative volume elements (RVEs) of the fabricated nano-composites are built by adding periodic boundary conditions (PBCs). In this way, RVEs with different volume fractions and particle sizes of SiC are produced and put into the simulation of tension tests. The elasticity and strength in single axial tension obtained from MD analysis are in good agreement with those calculated according to the rule of mixture. It is found that the dispersion of SiC particles into the Al matrix leads to a significant enhancement in the strength of nano-composites compared to pure Al, which is also dramatically affected by both the volume fraction and particle size. Additionally, the Al/SiC nano-composites with finer SiC particles get greater enhancement in the mechanical behavior than those with coarser ones. MD analysis clearly shows the contributions of load-transfer effect, thermal mismatch strengthening and Orowan strengthening to the strengthening of Al/SiC nano-composites.

Wire Mesh/Ceramic Particle Reinforced Aluminium Based Composite Using Explosive Cladding

In this study, dissimilar grade aluminium plates were explosively cladded by placing a wire mesh/ceramic particle between them. The stainless steel 316 mesh with 90o orientation and SiCp (1.5 volume %) are employed to enhance the mechanical properties of the aluminium composites. Microhardness and microstructure of the explosively cladded composite materials were evaluated. Significant improvement in the microhardness of the wire mesh/ceramic particle reinforced aluminium composite is established.

Corrosion Behaviour of Red Mud Particulate Reinforced Aluminium 6013 Composites by Potentiodynamic Polarization

Corrosion Behaviour of Red Mud Particulate Reinforced Aluminium 6013 Composites by Potentiodynamic Polarization

RETRACTED: Characterization of Particulate-Reinforced Aluminium 7075 / TiB2 Composites

Abstract Aluminum-based metal matrix composite (MMC) materials are used in the design of ground transportation vehicles and aircraft due to its light weight and high strength to weight ratio. Compared with conventional, unreinforced alloys, composite materials usually exhibit higher strength, both at ambient and elevated temperatures, as well as good fatigue strength and wear resistance. Stir casting process is one of the most effective methods for manufacturing Metal matrix composites (MMCs) due to its high volume reinforcement and fairly uniform distribution. This work deals with the production of Aluminium 7075 alloy reinforced with TiB 2 particle. The composites were fabricated by three varying the volume% of Titanium diboride (TiB 2 ) particles. The mechanical properties and microstructure analysis are identified from the experimental results and the ability of the manufactured aluminium matrix composite from the different reinforcements.

An investigation of the influence of phases’ removal ways on surface quality in micro milling SiCp/Al composites

SiC particle-reinforced aluminum matrix (SiCp/Al) composites are widely employed due to their outstanding performance. However, since they are composed of brittle SiC and ductile aluminum, the different removal mechanisms of the two phases may affect the surface quality in micro milling. In this paper, an experimental investigation of micro milling a kind of 45% SiCp/Al composites is presented. Using different values of the feed rate, the changes of the removal ways of the two phases are shown by 3D surface roughness and surface morphology. The results indicate that the surface roughness decreases firstly and increases later with the feed rate growing, which may be caused by the change of the removal way of the particle. A criterion for that is built. SEM pictures show that the surface is significantly coated by aluminum matrix when the feed rate is small; as the feed rate increases, the coating effect of the matrix weakens, and the removal ways of the particle changes from ductile regime machining to brittle fracture. Smaller feed rate may lead to the incompletely removing (plowing) of the Al and make the soft matrix coat the surface, while larger feed rate may result in the particle fracture, producing large numbers of cracks and damaging the surface integrity. Using suitable feed rate, the Al matrix can be removed efficiently and the SiC particle can be cut in its ductile regime. The unit of the suitable removal ways of Al matrix and SiC particle in machining process can produce a better surface.

TiO2 ceramic particles-reinforced aluminum matrix composite prepared by conventional, microwave, and spark plasma sintering

Aluminum-10 wt% TiO2 metal matrix composites were fabricated with conventional, microwave, and spark plasma sintering processes. Aluminum and nano-sized TiO2 powders were mixed using a high-energy mixer, and the sintering process was done at 450℃ by spark plasma sintering and 600℃ under both microwave and conventional heating. The results showed microwave sintering led to form Al3Ti intermetallic compounds with flaky shape, while in the conventional heating at the same sintering temperature, Al3Ti was formed and confirmed by X-ray diffraction and scanning electron microscope investigations. Moreover, the nano-sized TiO2 particles as reinforcement with no additional phase were obtained by spark plasma sintering at the lowest sintering temperature. The maximum bending strength of 254 ± 12 MPa and Vickers hardness of 235 ± 13 were measured for samples sintered in microwave as a consequence of Al3Ti formation. The SEM and energy-dispersive X-ray spectroscopy analyses showed uniform distribution of Al3Ti particles in the microstructure of microwave sintered samples and nonuniform distribution of agglomerated Al3Ti particles and porosities in samples sintered by spark plasma sintering and conventional heating.

Wear resistance of basalt particulate-reinforced stir-cast Al7075 metal matrix composites

The work is aiming to understand the dry sliding wear behavior of basalt particulate-reinforced aluminum 7075 composites. Aluminum 7075 and basalt particulate is used as matrix and reinforcement materials. Different wt% of composites is produced by stir casting process. It is observed from the SEM images that basalt particulates are uniformly distributed over the aluminum matrix. It is observed from the experimental result that the hardness of the composites increases with increases in wt% of the reinforcement. Addition of reinforcement increases the wear resistance and decreases the coefficient of friction. The worn surface of the composites is analyzed in detail and wear mechanism is reported.

High-Temperature Active Soldering of SiC Particle-Reinforced Al-MMC Using a Novel ZnAlGaMgTi Filler Metal

In order to broaden the application of SiC particle-reinforced aluminum matrix composite in electronics packaging, newly developed ZnAlGaMgTi filler with a low melting point of 418-441 °C was utilized as filler metal for active soldering of aluminum matrix composites (70 vol.%, SiCp/Al-MMCs) for the first time. The effect of loading pressure on joint properties of ZnAlGaMgTi active filler was investigated. The experimental results indicated that novel filler could successfully solder Al-MMCs, and the presence of Mg in the filler enhanced the penetration of Zn, while the forming of Zn-rich barrier layer influenced the active element MPD (melting point depressant) diffusion into parent composite, and the bulk-like (Mg-Si)-rich phase and Ti-containing phase were readily observed at the interface and bond seam. With the increase in loading pressure, the runout phenomenon appeared more significant, and the filler foil thickness and the Zn penetration depth varied pronouncedly. Sound joints with maximum shear strength of 29.6 MPa were produced at 480 °C at 1 MPa, and the crack occurred adjacent to the boundary of SiC particle and then propagated along the interface. A novel model describing the significant mutual diffusion of Al and Zn atoms between the parent material and solder was proposed.

A study of grinding forces of SiCp/Al composites

In this study, the grinding experiments were conducted on SiC particle-reinforced aluminum matrix (SiCp/Al) composites under wet, dry, cryogenic, and ELID grinding conditions, and the effects of grinding depth and table speed on grinding forces and grinding force ratio were investigated. The experimental results showed that both the normal and tangential grinding forces of SiCp/Al composites increased evidently with the increasing of the grinding depth and table speed under the four grinding conditions. And the grinding forces under the cryogenic condition were the largest, the grinding forces under the dry condition were the second, and the grinding forces under the wet condition were the minimum. Additionally, the grinding force ratio values decreased with the increase of grinding depth under the wet and dry conditions, while the grinding force ratio values increased slightly with the increase of the grinding depth under the cryogenic and ELID grinding conditions. The grinding force ratio was minimum under ELID grinding condition.

Wear properties of 10 vol.% silicon carbide particulate-reinforced aluminum composite fabricated by powder injection molding

Wear properties of aluminum matrix composites reinforced with silicon carbide particulate of 10 vol.% addition was investigated in as-sintered and heat-treated conditions under varying loads at -5, -25, -45 and -65N using a ball on flat type of wear test. The composite was fabricated by powder injection molding and sintering at 650 °C for 3 hours. Solution treatment was carried out at 550 °C for 2 hours followed by age-hardening at 160 °C for 6 hours. SEM and XRD results indicated Al and SiCp are present as matrix and reinforcement, while AlN, Al2Cu and Mg2Si were also detected. Further precipitation of Al2Cu and Mg2Si in heat-treated samples promoted maximum macro and micro Vickers hardness values, which were achieved at 161 and 157 Hv respectively. Wear weight loss increased with increasing minus load level. The coefficient of friction was found in the range of 0.042-0.048. Wear mechanisms were determined as the combination of abrasive, adhesion and oxidation.

Micromechanical simulation on strength and ductility of two kinds of Al-based nanostructural materials

The nanostructured Al-based composites possess the combination of high yield strength and good ductility. In this paper, a micromechanical model is presented to simulate the mechanical response of bimodal nanostructured Al and the particle-reinforced aluminum matrix composite (PAMC). The constitutive relations for different phases are addressed in the model, as well as the contribution of microcracks. Numerical results show that the model can successfully describe the enhanced strength and ductility of the bimodal nanostructured Al, and the predictions of the PAMC are in good agreement with the experimental data. It is worth noting that the strength and ductility are sensitive to the volume fraction of constituents and the distribution of microcracks in both bimodal nanostructured Al and PAMC. Therefore, the present theoretical results can be used to optimize the microstructure for improving the mechanical properties of nanostructured Al-based composites.

Characterization of material removal in ultrasonically assisted grinding of SiCp/Al with high volume fraction

Due to the significant difference between the reinforcement grains and matrix phase, the machining of SiC particle-reinforced aluminum composites (SiCp/Al) is difficult and costly, especially for SiCp/Al with volume fraction higher than 50%. Ultrasonically assisted grinding (UAG), which has unique advantages in the machining of both ductile and brittle materials, is a promising solution of the machining of SiCp/Al. This study conducts both UAG and conventional grinding (CG) process on SiCp/Al with an electroplated diamond wheel. The study explores material removal mechanisms involved in UAG in comparison to that in the CG. It also investigates grinding forces, surface integrity, subsurface damage, and wheel wear. The study finds that material removal in grinding of SiCp/Al is dominated by SiC particle fracture that is induced in the grinding process. The ground workpiece is smeared with an aluminum layer, making it difficult to evaluate surface integrity. Compared with CG, UAG of SiCp/Al results in similar surface integrity in terms of surface roughness and subsurface damage, but a much lower grinding force (35–50% lower).

Simulation study of the influence of cutting speed and tool–particle interaction location on surface formation mechanism in micromachining SiCp/Al composites

The SiC particle-reinforced aluminum matrix composites are widely employed in different fields due to their outstanding performance. An in-depth understanding of their surface formation mechanism will pave a solid foundation for the widespread application. In this paper, two-dimensional microscale finite element models composed of a SiC particle and Al2024 matrix are established. The effects of cutting speed and tool–particle interaction location on particle behavior and surface formation during micromachining process are investigated. The location is categorized into two scenarios (tool cuts the upper and the lower part of the particle) and different cutting speeds for each scenario are presented. As a result, in scenario one (tool cuts the upper of the particle), the particle fractures by brittle fracture while the depth of surface defects decreases with increase of the cutting speed; in scenario two (tool cuts the lower part), the removal way of the particle changes from being pulled out to being crushed as the speed increases. The von Mises equivalent stresses of the particle and the matrix at the two scenarios are analyzed to explain these phenomena. Experimental measurements of micromilled surfaces are compared with simulation, showing promising results.

TEM microanalysis of interfacial structures after dry sliding of cold sprayed Al-Al2O3

Particle-reinforced aluminum matrix composites (Al-MMCs) generally exhibit lower wear rates and more stable friction than their un-reinforced matrix materials. Cold spray is a popular consolidation route for Al-Al2O3, allowing for its application as a coating for corrosion and tribological protection. Previous work by the authors has found that 22wt.% of angular Al2O3 particles (sample ANG22) leads to a significant decrease of the third body source flow and of the recirculation third body flow leading to a drastic decrease of the wear flow and thus of the wear rates. The greater friction stability in the case of sample ANG22 during dry sliding against sapphire compared to unreinforced pure Al cold sprayed coatings (sample CS0) is attributed to a specific thin third body to be characterized. Thus the goal of the present work is to compare the near-surface third body material for samples CS0 and ANG22 in terms of microstructure and chemistry, with transmission electron microscopy (TEM) methods, in relation to their hardness.

Multi-scale modeling of thermal conductivity of SiC-reinforced aluminum metal matrix composite

High thermal conductivity is one important factor in the selection or development of ceramics or composite materials. Predicting the thermal conductivity would be useful to the design and application of such materials. In this paper, a multi-scale model is developed to predict the effective thermal conductivity in SiC particle-reinforced aluminum metal matrix composite. A coupled two-temperature molecular dynamics model is used to calculate the thermal conductivity of the Al/SiC interface. The electronic effects on the interfacial thermal conductivity are studied. A homogenized finite element model with embedded thin interfacial elements is used to predict the properties of bulk materials, considering the microstructure. The effects of temperatures, SiC particle sizes, and volume fractions on the thermal conductivity are also studied. A good agreement is found between prediction results and experimental measurements. The successful prediction of thermal conductivity could help a better understanding and an improvement of thermal transport within composites and ceramics.

The effect of reinforcement type on the microstructure, mechanical properties, and wear resistance of A356 matrix composites produced by FSP

Fabrication of particle-reinforced aluminum matrix composites has been pursued with a keen interest recently. However, a comparison of the effect of different reinforcements on the mechanical properties and wear resistance of A356 matrix composites fabricated by FSP is of great interest to be considered. In the present work, the microstructural, mechanical, and wear properties of A356 matrix composites reinforced by SiC, TiC, ZrO2, and B4C particles are investigated. Moreover, the effect of pin profile on distribution of reinforcing particles in the stir zone of the FSPed specimens is investigated. Hardness and wear tests are performed in order to investigate mechanical and wear properties of the composites. The composite reinforced by TiC particles exhibits higher hardness value compared with other reinforcements due to the excellent bonding between TiC and metal matrix as well as higher hardness value of reinforcement itself than other reinforcements. Moreover, wear test results show that the wear resistance of the composite is significantly improved compared with that of the base metal.