Aluminum-based Matrix Research Articles

Parts repairing and microstructural refinement of high-pressure die cast aluminum alloys through friction stir processing for bulk production

A key challenge in the production of high-grade automotive aluminum components through the High-Pressure Die Casting (HPDC) process is the imperative to minimize imperfection. In addressing this concern, this study utilizes friction stir processing (FSP), a widely recognized intense plastic deformation technique. FSP is applied to systematically alter the microstructure of HPDC Al-4Mg-2Fe, a prominent alloy extensively used in the die-casting sector. By using the pass strategy to incorporate both one-pass and two-pass approaches, the microstructure is selectively altered to establish a defect-free processed zone. The utilization of FSP demonstrates its efficacy in breaking aluminum dendrites and acicular silicon particles, leading to a uniformly dispersed arrangement of equiaxed silicon particles within the aluminum-based matrix. In addition, FSP eradicates porosity and disintegrates needle-like Fe particles, resulting in a more refined and homogeneously distributed structure. Subsequently, the material's mechanical properties processed by FSP were assessed in the longitudinal direction concerning the processing axis and then compared with those of the original base material.The microstructural refinement and reduction in porosity induced by FSP result in a notable enhancement in hardness, with an increase of 23 % after one pass and 37 % after two passes. The substantial improvement in mechanical properties during the FSP process is predominantly attributed to modifications in the morphology, refinement, and dispersion of intermetallic particles within the matrix. This improvement is further complemented by the ultrafine dispersion of casting defects.This study underscores the efficacy of FSP as a valuable tool for modifying microstructures and improving mechanical properties in HPDC Al-4Mg-2Fe alloys. Such advancements align with the lightweighting objectives pursued by the automotive industry.

Aluminum Alloys and Aluminum-Based Matrix Composites

Due to air pollution and energy shortages in the contemporary world, weight lighting for transportation vehicles and energy conservation, as well as emission reductions, are necessary to achieve carbon neutrality and fuel conservation [...]

Hydrogen trapping and permeability in carbon fiber reinforced aluminum alloys

Carbon fibers and aluminum-based alloys are the most common choice for today's advanced hydrogen storage solutions due to their lightweight. They also combine exceptional mechanical performance and resistance to most chemicals. However, carbon fibers alone are the primary cost driver for hydrogen storage systems and high-strength aluminum alloys suffer from hydrogen embrittlement. Therefore, alternative carbon fiber-reinforced aluminum alloys can be considered to optimize storage tank costs. But, the effect of adding of carbon fibers on hydrogen trapping in an aluminum-based matrix has not yet been understood. To elucidate this, in this study, the interaction between hydrogen and a carbon fiber-reinforced aluminum alloy was investigated by correlating nano/microstructure characterization, hydrogen mapping techniques, and high-pressure hydrogen permeation tests. It is suggested that carbon fiber-reinforced aluminum alloy has three additional hydrogen trap sites compared to the reported traps for the aluminum alloy. The results showed that hydrogen trapping at these traps reduces the hydrogen permeability of composite material compared to a monolithic aluminum alloy.

Investigation and development of aluminium matrix composite reinforced with silicon carbide using process of stir casting

Aluminium-based matrix composites (AMCs) have applications in different engineering fields due to their tremendous potential. In the present work, an economical stir casting process was done to make aluminium matrix composite reinforced with Silicon Carbide. For the making of composite samples various experimental factors used were stirring speed (1000 rpm, 800 rpm and 500 rpm), stirrer duration (6 min, 4 min and 2 min) and Silicon carbide (SiC) content (5 %, 10 % and 15 % by wt.), using Taguchi L9 orthogonal array. Tensile strength, hardness and wear analysis were done on the machined samples which were first designed using computer-aided design (CAD) software as per the standards. Grain structure and particle distribution were studied by performing tests using optical microscopy and Scanning electron microscopy (SEM). The pure aluminium samples had less wear resistance and deteriorated mechanical properties than the fabricated composites. ANOVA results illustrated that %wt. of SiC and stirring speed was the most prompt factor for wear, tensile strength and hardness. Minitab software based on Taguchi L9 orthogonal array (OA) was used to optimize the input process parameters and photo-micrographs were used to support the results.

Dynamics of thermal motion of liquid lead nanoinclusions attached to fixed dislocations coupled in a dislocation node in the aluminum-based matrix

ABSTRACT Thermal motion of four liquid lead nanoinclusions attached to fixed dislocation segments joining in a dislocation node in aluminum-based alloy at 485°C is studied in-situ using TEM. The mutual interaction of the inclusions in all pairs is detected demonstrating the collective interaction of the all inclusions. The time-correlated thermal motion of each of the inclusions, and time-correlated thermal motion of the inclusions in all the pairs are indicated. Phase spectra of the time dependencies of the positions of the inclusions on the dislocations obtained using FFT reveal an existence of a common harmonic in their thermal oscillations at low frequencies demonstrating synchronous oscillations of the inclusions. The transition between synchronous and asynchronous dynamics of the thermal oscillations of the inclusions with increasing frequency is observed. The external vibrations introduced by the inclusion attached to the dislocation node are probably the reason for this transition.

An investigation on microstructure and mechanical behaviour of aluminium hybrid metal matrix nanocomposite fabricated through electromagnetic stir casting process

This study focuses on the microstructure characteristics and mechanical properties of unreinforced and reinforced ceramic materials titanium diboride (TiB2) and graphite (Gr). Aluminium hybrid metal matrix nanocomposites reinforced with varying weight percentage of nano TiB2 (0-12.5 wt. %) and nano Gr (4wt %) via electromagnetic stir casting process to produce hybrid nanocomposites samples. Identification of phases and microstructure analysis are performed through X-ray diffraction, Optical Microscope and Scanning Electron Microscope with Energy Dispersion X-ray Spectrum. Mechanical properties such as hardness, tensile, compression and flexural strength were investigated on the prepared hybrid nanocomposites samples. Microstructure images of the samples reveals uniform dissemination of reinforced TiB2 and Gr nanoparticles in Aluminium base matrix and X-ray diffraction confirms the presence of reinforced particles TiB2 and Gr in Aluminium base matrix. Concluded from the consolidated samples, mechanical properties of the reinforced samples improved as compared to the matrix material.

High-performance aluminum-based matrix composites reinforced with high content of boron nitride nanosheets

The dispersion of high content boron nitride nanosheets (BNNSs) in metals to form composites is challenging due to their high specific surface area. Here, Al-based matrix composites with high content of BNNSs were successfully prepared by shift-speed ball milling with step-by-step addition of BNNSs and finally direct current sintering (DCS). Such ball milling method can effectively disperse BNNSs onto the existing Al surface and the fresh Al surface generated by ball milling, allowing for a high content of BNNSs homogeneously dispersed within the composites. Al matrix and BNNSs were tightly bonded and underwent moderate interfacial reactions, forming AlN, AlB2, and AlB10. The effects of BNNSs content on the tensile properties of BNNSs/Al composites were investigated. The ultimate tensile strength of 2.0 vol% BNNSs/Al composites reached 220 MPa, which was 69% higher than that of ball milled pure aluminum. The load was effectively transferred form Al matrix to BNNSs..

Developments of discontinuously reinforced aluminium matrix composites: Solving the needs for the matrix

Metal matrix composites become interesting for use as constructional and functional materials. The development of metal matrix composites was primarily directed to the continuous-fibre reinforced metal matrix composites - such as boron fibre/aluminium-based matrix, continuous alumina fibres /aluminium-based matrix, graphite fibre/aluminium-based matrix or graphite fibre/magnesium-based matrix composites. Despite the successful production of these metal matrix composites, they manufacturing was limited by the concerns related to the technological processes and cost, their availability remaining a significant barrier to their manufacturing. The benefits of metal matrix composites as compared to the unreinforced (monolithic) metals or alloys include superior mechanical and physical properties that deliver improved structural performance. This concept also further implies re-using materials or using recycled materials. Therefore, discontinuously reinforced metal matrix composites are suitable for a wide range of industrial applications. This study aims to investigate the developments in area of solving the needs for the matrix material necessary for the discontinuously reinforced aluminium matrix composites. Aluminium can be recycled directly back into itself over and over again in a true closed loop.

High-Performance Aluminum-Based Matrix Composites Reinforced with High Content of Boron Nitride Nanosheets

High-Performance Aluminum-Based Matrix Composites Reinforced with High Content of Boron Nitride Nanosheets

Research and Development of Fuel Rods Metallurgically Bonded with Fuel Cladding for Nuclear Installations

The design and scheme for manufacturing fuel rods metallurgically bonded with ribbed aluminum claddings using hot isostatic pressing and contact-reactive brazing are presented. It is shown that the developed scheme can be used both for production of dispersive fuels and high-density fuels based on uranium alloys. The results of investigations of brazed joints of aluminum cladding with a matrix composition based on aluminum and with samples of E110 alloy through copper and silumin coatings are presented. The results of research of brazed joints of an aluminum cladding with an aluminum-based matrix composition and samples of zirconium alloy E110 made through copper and silumin coating are presented. The strength of brazed joints, composition of diffusion layers formed as a result of contact-reactive brazing in a high vacuum have been determined. The modes of hot isostatic pressing that provide crimping of the ribbed cladding of fuel pellets and rods and obtaining a metallurgical bonding between their surfaces have been defined. It is shown that satisfactory bond strength is provided starting from the temperature of 610 °С. The maximum strength values obtained on the compounds Al-(Al+12% Si)-Zr and Al-Cu-Zr are 57.0 MPa and 55.3 MPa respectively. The fracture of the of aluminum samples joints, obtained with the Cu layer at a temperature of 620 °C, occurs on threaded joints at the strength value of 82 MPa. The results of research of the composition of diffusion layers formed by brazing compounds Al-(Al + 12% Si)-Zr and Al-Cu-Zr are presented. It was established that hot pressing provides the best results for manufacturing of fuel rod dummies in the studied range of modes at a temperature of 630 °C, a pressure of 380 MPa and exposure of 20 minutes.

Effect of ball-milling process parameters on mechanical properties of Al/Al2O3/collagen powder composite using statistical approach

Chrome containing leather-wastes (CCLW) is a waste obtained from leather industries. These wastes always produced environmental pollution. However, CCLW can be utilized in the production of various materials. In this research, chromium in the form of collagen powder after extracting from CCLW has been utilized to fabricate the composite material. Extracted collagen was mechanically alloyed with alumina ceramic fragments to acquire in a separate unified facility. Response surface methodology (RSM) was employed to obtain the optimum combination of solid-state synthesis processing variables. Optimum mechanical-alloying parameters were found to be ball-to-powder weight-ratio (BPR) of about 5, ball milling speed of about 178 rotation per minute and ball-milling time of about 93 h. The microstructure of ball processed reinforced composite material demonstrated a uniform distribution and proper wettability in aluminum-based matrix material. Tensile strength and hardness of Al/5% Collagen/5% Al2O3 composite material were enhanced by about 38.25% and 45% respectively. However, the density, toughness and ductility of composite material were reduced by 0.16%, 25% and 24.24% respectively. Surface roughness of Al/5 wt.% Collagen/5 wt.% Al2O3 composite was found to be 3.10 μm at a speed of 190 m/min, feed of 0.14 mm/rev and depth of cut of 0.20 mm.

Synthesis and Mechanical Behavior of Ball-Milled Agro-Waste RHA and Eggshell Reinforced Composite Material

Abstract Nowadays, there are various industrial wastes from industries that produce lots of environmental pollution. Rice husk ash (RHA) is agricultural waste and eggshell waste is industrial waste. These wastes also produce lots of soil pollution. However, by utilizing these wastes, some environmental problems can be reduced. In the present investigation, an attempt was made to utilize RHA and eggshells as reinforcement material in the development of aluminum-based composite material. Carbonized eggshell ash (CESA) particles and RHA were ball-milled for 75 hours to obtain a single entity. The mixture of CESA and RHA particles has been varied from 2.5 % to 12.5 % in the development of the composite. Ball-milled reinforcement particles in the single entity showed uniform distribution in the aluminum-based matrix material. Results showed that after the heat treatment process, the tensile strength and hardness of the aluminum/5 % CESA/5 % RHA composite was found to be 189.95 MPa and 56 brinell hardness number (kgf/mm2) respectively. The tensile strength and hardness of the composite after heat treatment were enhanced by 31 % and 60 %, respectively. However, the toughness and ductility were reduced after adding the mixture of carbonized eggshell particles and alumina in the aluminum alloy. Corrosion loss and thermal expansion behavior were also observed to identify the carbonized eggshell and RHA addition in the aluminum alloy. Corrosion loss and thermal expansion of the AA3105/5 % eggshell powder/5 % RHA composite after heat treatment were found to be 0.011 gm and 4.35 mm3, respectively.

The extraordinary effect of very low content of hybrid carbonaceous reinforcement on the microstructural and mechanical properties of 7075 aluminum alloy

Until recently, the strengthening efficiency of carbonaceous reinforcements in aluminum-based matrix nanocomposites (AlMNCs) was lower than expected. The intrinsic characteristics of matrix and carbonaceous reinforcements and fabrication technique, which affected the microstructural characterization, played main roles in determining the performance of Cs/AlMNCs. In this study a novel strategy was developed via flake powder metallurgy followed by slurry blending combined with rheocasting and hot-extrusion processing to prepare hybrid AA7075-matrix composite reinforced with CNTs + GNPs. No Al4C3 phase was detected in Raman spectrums, while uniform dispersion of carbonaceous hybrid reinforcements with minimal structural damage was observed. There were ~ 9% and 39% decrease in the average grain size of the as-casted and extruded CNTs + GNPs/AA7075 composites, respectively, compared to AA7075 alloy. In the extruded CNTs + GNPs/AA7075 composite, plate precipitates were predominant and some lath-like dynamic precipitates were observed at the GNPs/AA7075 interfaces. The micro-hardness, tensile yield strength (TYS), ultimate tensile strength (UTS) and uniform elongation (UE) of the CNTs + GNPs/AA7075 composite were improved by ~ 17%, 51%, 7% and 20% compared to AA7075 alloy. An ultra-high yield strengthening efficiency of carbonaceous hybrid reinforcements in AA7075 alloy up to 3950 was obtained, where load bearing was the main strengthening mechanism and carbonaceous reinforcements illustrated bridging and pulling-out in the fracture surfaces of composite.

Effect of Silicon Content on wear and Hardness of Al-Si Alloys

In the current work the Al-Si composite is prepared using stir casting method with variation in the percentage(4%, 6% and 8%) of the Si particles in it. stir casting method is one of the cheapest method for production of Al alloys. The prepared composites of different percentages of Si are investigated for it wears behaviour using Pin-on-Disk machine and other properties like hardness. Characterization of Worn surface of the composite is done using SEM. Among the metallic matrices, the aluminum-based matrix remains the most studied metal matrix material for the production of MMCs. This is largely due to the large variety of properties provided by aluminum-based matrix composites at low manufacturing costs. While many Metal Matrix Composites ( MMCs) are desirable for use in various industrial applications, Aluminum Matrix Composites ( AMCs) are the most commonly used in specialized applications because they combine reasonable strength, low density, durability, machinability, availability, performance and price. In aerospace applications, the excellent tribological characteristics of Al-Si and Al-Sn alloys have led to their widespread use, especially in plain bearings, cylinder liners and internal combustion pistons. It is seen that Si is uniformly distributed in the Al matrix and hardness increases to 71BHN with 8%Si in Al matrix. Further analysis revealed that the microstructure homogeneity of the samples is strongly affected its hardness and Wear rate decreases with increase in Si.

Behaviour of Al2O3 in aluminium matrix composites: An overview

In this paper, behaviour of Al2O3 in aluminium matrix composites is reviewed for its properties and applications. In addition, many metal matrix composite fabrication processes are also elaborated. In the present days the aluminium metal matrix composite is in high demand because of its superior properties. Its demand is still on rise because of its widespread use in automotive industries, aerospace industries and marine industries. The method of the fabrication of aluminium matrix-based composite is also a deciding factor for its resultant properties. Desired composite-properties are achievable by proper selection of reinforcing materials as well as the physical conditions. Various sections of current information compile the details about the behaviour of alumina particles in aluminium-based matrix for formation of metal matrix composites.

WITHDRAWN: Effect of jet machining parameters on output features for hybrid composites-A review

Abstract This paper provides review on various parameters and output parameters for hybrid composites. It is a non-traditional method of machining the tough materials such as matrix and hybrid composites these are widely used in automotive industries, aerospace and other industries. Most of the research work in MMCs is performed on aluminium-based matrix reinforced in different proportions with ceramics such as silicon carbide (SiC) and aluminium oxide (Al2O3) have a major influence on process.

Flyash and carbon fibers reinforced aluminum-based matrix composite for structural applications

Aluminum alloy and its composite showed excellent physical and mechanical properties. But still, there is a scope in improving the mechanical properties of the composite for the structural, automobile, and aerospace industry. The composites have been prepared to reach the needs of the industry. In this present work, micro-fillers such as fly ash, and carbon fiber reinforcements were added to the base AA7076 matrix and fabricated the composite using a motorized stir casting technique. AA7076/fly ash and AA7076/carbon fiber composites were prepared by varying wt.% percent of fly ash and carbon fiber reinforcements (0.5, 0.75, 1, and 1.25 wt.%) and results were compared. The SEM micrographs revealed the homogeneous distribution of fly ash and carbon fiber reinforcements along the grain boundaries of the AA7076 matrix material. The composites with 1 wt.% of micro-fillers showed superior hardness and tensile strength as compared to other reinforcement composite and base matrix. The experimental test results revealed that the addition of fly ash and carbon fiber reinforcements improved the mechanical properties of the AA7076/fly ash and AA7076/carbon fiber composites as compared to the AA7076 matrix material. Among them, the comparative study revealed that the AA7076/carbon fiber composite has showed homogeneous distribution of reinforcements and improved mechanical properties.

Aluminum Alloy Matrix Composite Reinforced with Metallic Glasses Particles Using Hot-Roll Bonding

Composite materials (CMs) exhibit high hardness, mechanical strength, and wear resistance, but their processing properties are limited. The most popular reinforcements for composites are carbides, nitrides, and oxides. Amorphous metallic materials are an alternative reinforced component. Metallic glass can provide increased properties due to higher interphase strength between their particles and the metallic matrix when compared with nonmetallic particles. A sheet of metal matrix composite has been processed by roll bonding. The composite consists of an aluminum-based matrix reinforced by particles of Co48Cr15Mo14C15B6Tm2 metallic glasses and a cladding layer of AA5083 alloy. The thickness of the central layer of Al–5% Zn–5% Ca alloy reinforced by metallic glasses particles is 60% of the total thickness of the sheet, and the thickness of the cladding layer is 20% on the both sides. Granules of the CM were processed by mechanical alloying with the subsequent consolidation to the balk sheet by roll bonding in clad sheets at the temperature below class transition temperature of the amorphous component. The reinforcement compound retains the amorphous state after mechanical alloying and hot rolling, which is shown by X-ray and differential thermal analysis. The microstructure after different processing steps is studied by scanning electron microscopy and the mechanical properties of the metal matrix composite sheet at room temperature are studied. Amorphous particles have a size range of 2 to 187 μm and volume fraction of about 10%. The hardness of the composites is 25% higher than the hardness of basic alloy Al–5% Zn–5% Ca. The yield strength of the cladded CM is two times higher than that of metallic alloys of the matrix and cladding.

Electrochemical investigation of calcined agrowastes powders on friction stir processing of aluminium-based matrix composites

The ultimate goal of this report was to use eco-friendly calcined agro-waste powders such as coconut shell ash (CSA), cow bone ash (CBA) as well as palm kernel shell ash (PKSA) and to analyze the percentage inhibition performance efficiency (percent IPE) on friction stir processed (FSP) of super strength aluminum alloy 7075-T651. The motive behind this study was to establish whether agro-waste powders could serve as a successful alterative to metallic powders for enhancing as well as corrosion resistance in aluminum alloy 7075-T651. The study reported three different carbonaceous agro-waste powders such as PKSA, CBA and CSA in 3.5 percent NaCl as reinforcements and corrosion prevention and confirmed that PKSA as corrosion susceptibleperformed better than CBA and CSA under the same environmental factors and can be an acceptable substitute for metallic powders as a corrosion protection. The results established that PKSA has the least corrosion rate of 0.4357 mm/year and this was followed by the reinforcement from CSA with 0.8291 mm/yr and lastly 1.42284 mm/yr for CBA. In the same vein, reinforcing with PKSA yielded the highest polarization resistance with 1075.6 Ω and this was followed by the reinforcement of CSA with 564.4 Ω and CBA of 276.42 Ω.

Tribological, structural and mechanical characteristics of friction stir processed aluminium-based matrix composites reinforced with stainless steel micro-particles

Tribological, structural and mechanical characteristics of friction stir processed aluminium-based matrix composites reinforced with stainless steel micro-particles