Properties Of Aluminum Foams Research Articles

Fabrication of Two-Layer Aluminum Foam Consisting of Dissimilar Aluminum Alloys Using Optical Heating.

Aluminum foam is a lightweight material and has excellent shock-absorbing properties. Various properties of aluminum foam can be obtained by changing the base aluminum alloy. Multi-layer aluminum foam can be fabricated by varying the alloy type of the base aluminum alloy, but with different foaming temperatures, within a single aluminum foam to achieve multiple properties. In this study, we attempted to fabricate a two-layer aluminum foam with the upper layer of a commercially pure aluminum A1050 foam and the lower layer of an Al-Si-Cu aluminum alloy ADC12 foam by using an optical heating device that can heat from both the upper and lower sides. Two types of heating methods were investigated. One is to directly stack the A1050 precursor coated with black toner on top of the ADC12 precursor and to foam it from the top and bottom by optical heating. The other is to place a wire mesh between the ADC12 precursor and the A1050 precursor and place the A1050 precursor on the wire mesh, thereby creating a space between the precursors, which is then foamed by optical heating from the top and bottom. It was shown that both precursors can be foamed and joined, and a two-layer A1050/ADC12 foam can be fabricated for both types of heating methods. In the method in which two precursors were stacked and foamed, even if the light intensity of the halogen lamps on the top and bottom were adjusted, heat conduction occurred between the stacked precursors, and the foaming of each precursor could not be controlled, resulting in tilting of the joining interface. In the method of foaming using a wire mesh with a gap between two precursors, it was found that by adjusting the light intensity, the two precursors can be foamed almost simultaneously and achieve similar pore structures. The joining interface can also be maintained horizontally.

Properties of Aluminium Cellular Materials Produced by Powder Metallurgy Using the Foaming Agent TiH2

A considerable attention is paid to the production and monitoring of the properties of metallic cellular structures and the properties of aluminium foams, respectivly. Foam structures can be manufactured in three basic ways (by blowing the external gas into the melt, by melt gasification due to the thermal decomposition of the foaming agent, by the melting of the foamable preform which contains foaming agent particles). The paper addresses to our publication [18] and furthermore focuses on the investigation of mechanical properties of two types of foamed AlSi12 aluminium alloy samples. Samples (150x25x10 mm) were produced by powder metallurgy using a foaming agent TiH2. The characteristics features of the produced foam structures (relative density, porosity, volume fraction of solids, Young's modulus of elasticity) were studied on AlSi12 alloy samples. In addition, the porosity of samples and continuity of their air cells were monitored usign the scanning electron microscope.

On the Effect of the Oxidative Milling of Matrix Powder on the Structure and Properties of Aluminum Foam Based on the Al–12Si Alloy

On the Effect of the Oxidative Milling of Matrix Powder on the Structure and Properties of Aluminum Foam Based on the Al–12Si Alloy

Manufacturing of Open-Cell Aluminium Foams: Comparing the Sponge Replication Technique and Its Combination with the Freezing Method.

The manufacturing of aluminium foams with a total porosity of 87% using the sponge replication method and a combination of the sponge replication and freezing technique is presented. Foams with different cell counts were prepared from polyurethane (PU) templates with a pore count per inch (ppi) of 10, 20 and 30; consolidation of the foams was performed in an argon atmosphere at 650 °C. The additional freezing steps resulted in lamellar pores in the foam struts. The formation of lamellar pores increased the specific surface area by a factor of 1.9 compared to foams prepared by the sponge replication method without freezing steps. The formation of additional lamellar pores improved the mechanical properties but reduced the thermal conductivity of the foams. Varying the pore cell sizes of the PU template showed that—compared to foams with dense struts—the highest increase (~7 times) in the specific surface area was observed in foams made from 10 ppi PU templates. The effect of the cell size on the mechanical and thermal properties of aluminium foams was also investigated.

Classification of Mechanical Properties of Aluminum Foam by Machine Learning

Classification of Mechanical Properties of Aluminum Foam by Machine Learning

Mechanical Properties of Aluminium Foam and How Density, Temperature, and Strain Rate Affect Dynamic Strain–Stress Relationship

Aluminium foam has been popular in engineering, and aluminium foam research has become a research hotspot. The strain–stress relationship of aluminium foam presents three distinct stages. In this paper, the mechanical behaviours of aluminium foam materials under dynamic and quasi-static compression are studied. The effects of density, strain rate and temperature on the dynamic mechanical behavior of aluminum foam were analyzed. Combined with the dynamic and static stress–strain curves of aluminium foam, the specific characteristics and the phenomena in every stage of the compression process were studied by high-speed photography and CT. The experimental results show that aluminium foam undergoes obvious collapse layerby-layer in the process of compression. The stress–strain curves include a considerable stress drop after the elastic stage. Moreover, the structural defects of the material will cause the plastic failure in advance, and the possibility of the existence of structural defects will be affected by the density. Under dynamic compression, with increasing density the strain rate sensitivity of aluminium foam increase, but with the temperature increasing, the strain rate sensitivity was decrease.

Mechanical properties and damping properties of carbon nanotube-reinforced foam aluminum with small aperture

Abstract

Application of New Multi-Scale Edge Fusion Algorithm in Structural Edge Extraction of Aluminum Foam

Accurate extraction of structural edge information of aluminum foam is an important method to study the complex structural properties of aluminum foam, but the conventional single-scale edge detection method is difficult to achieve complete extraction of structural edge information of aluminum foam. However, the multi-scale fusion edge detection method based on Gaussian smoothing also has some problems, such as strong edge diffusion, weak edge degradation, edge pixel movement and so on. In order to solve the shortcomings of the above methods, this paper proposes a multi-scale edge fusion algorithm based on texture suppression, which can extract the edge information of aluminum foam structure more accurately and completely. Firstly, preprocess the image. The illumination component of the image is extracted by the multi-scale fusion method, and the luminance of the image is corrected by the adaptive luminance correction method based on the two-dimensional gamma function. Secondly, construct multi-scale space. It is proposed to construct the guiding image of the guiding filtering by using the bilateral texture filtering and construct the multi-scale space by changing the scale factor of the guiding filtering. Both bilateral filtering and guided filtering have the function of suppressing the texture information of the image while maintaining the structural edge features of the image. Finally, extract edge seeds and fuse multi-scale edges. A new multi-scale image edge fusion algorithm is proposed, which uses seed edges as a medium to gradually merge multi-scale image edges. In order to extract the edge information of the foam aluminum cross-section structure more accurately and completely, the algorithm further optimizes the edge using gradient direction consistency and non-maximum suppression. In order to verify the feasibility of the proposed algorithm, this paper uses the dataset to test the proposed algorithm and a variety of existing algorithms, and compare the results of various algorithms by quantitative analysis. The experimental results show that the proposed algorithm is feasible and effective, and its performance is better than the comparison algorithm.

Mechanical, Thermal, and Acoustic Properties of Aluminum Foams Impregnated with Epoxy/Graphene Oxide Nanocomposites

Hybrid structures with epoxy embedded in open-cell aluminum foam were developed by combining open-cell aluminum foam specimens with unreinforced and reinforced epoxy resin using graphene oxide. These new hybrid structures were fabricated by infiltrating an open-cell aluminum foam specimen with pure epoxy or mixtures of epoxy and graphene oxide, completely filling the pores. The effects of graphene oxide on the mechanical, thermal, and acoustic performance of epoxy/graphene oxide-based nanocomposites are reported. Mechanical compression analysis was conducted through quasi-static uniaxial compression tests at two loading rates (0.1 mm/s and 1 mm/s). Results show that the thermal stability and the sound absorption coefficient of the hybrid structures were improved by the incorporation of the graphene oxide within the epoxy matrix. However, the incorporation of the graphene oxide into the epoxy matrix can create voids inside the epoxy resin, leading to a decrease of the compressive strength of the hybrid structures, thus no significant increase in the energy absorption capability was observed.

Research on Absorbing Properties of New Porous Metals Materials with Light Weight

The development of electronic science technology makes electromag-netic radiation problems increasingly severe. High-performance absorbing and shielding electromagnetic wave materials with light weight are researched and developed as one of effectiveness methods to restrain electromagnetic radiation and prevent information leakage. The absorbing properties of aluminium foams coating absorbing paint were studied and tested by making use of RCS in “the reflectivity testing measurement of radar absorbing material” of GJB 2038-94 in this work. The effect of absorbent species and metal base structure on absorbing properties of materials was discussed. The results indicate that the absorbing properties of materials coating magnetic dielectric absorbing paint are better than others, and that of the sample CFe are best in 12.0—18.0GHz, while that of the sample CNi’ are optimal in 26.5—40.0GHz; comparing with aluminium alloy plate materials, aluminium alloy foams have some absorbing properties, and after coating absorbing paint, absorbing properties’ improvement of aluminium foams are larger than of aluminium alloy plate that were resulted from complex porous structure mainly of aluminium foams’.

Trends of Joining Composite AlSi-SiC Foams

Abstract The paper consist of characterization of the essence of structure, properties and application of AlSi-SiC composite foams as well as limitations and possibilities of their joining. Porous structure with porosity up to 80% and exceptional properties of aluminium foams are the reason of their numerous application and interest of their joining. Consideration of methods of welding, soldering and gluing AlSi9-SiC10 composite foams, the joint structure, and properties. Recommendations for surface preparation of foam, and different joining procedures aimed at control the porosity of the foam and glued surface roughness were established. Result of EDS and XRD investigations of the AlSi9-SiC10 composite foams joint were considered.

Prediction of the Stress–Strain Behavior of Open-Cell Aluminum Foam under Compressive Loading and the Effects of Various RVE Boundary Conditions

The prediction of the mechanical behavior of metallic foams with realistic microstructure and the effects of various boundary conditions on the mechanical behavior is an important and challenging issue in modeling representative volume elements (RVEs). A numerical investigation is conducted to determine the effects of various boundary conditions and cell wall cross sections on the compressive mechanical properties of aluminum foam, including the stiffness, plateau stress and onset strain of densification. The open-cell AA6101-T6 aluminum foam Duocel is used in the analyses in this study. Geometrical characteristics including the cell size, foam relative density, and cross-sectional shape and thickness of the cell walls are extracted from images of the foam. Then, the obtained foam microstructure is analyzed as a 2D model. The ligaments are modeled as shear deformable beams with elastic-plastic material behavior. To prevent interpenetration of the nodes and walls inside the cells with large deformations, self-contact-type frictionless interaction is stipulated between the internal surfaces. Sensitivity analyses are performed using several boundary conditions and cells wall cross-sectional shapes. The predicted results from the finite element analyses are compared with the experimental results. Finally, the most appropriate boundary conditions, leading to more consistent results with the experimental data, are introduced.

Fabrication and characterization of hypoeutectic open-cell Al-Si foams using gravity die casting and squeeze casting

Gravity die casting and squeeze casting are the techniques used for the fabrication of hypoeutectic open-cell Al-Si foams which are characterized and studied for their energy absorbing quality in compression tests. The effect of different amounts of sodium chloride (NaCl) (up to 56 vol.%) as a space holder in the casting of aluminum foam on the morphology, density, porosity, compressive and energy absorption properties of aluminum foam was studied. The hypoeutectic Al-Si alloy with NaCl particles as a space holder was used to fabricate the aluminum foam using gravity die casting and squeeze casting. The hypoeutectic open-cell Al-Si foams produced by squeeze casting showed smaller pore size, better pore distribution, higher porosity, good compressive strength and greater energy absorption energy compared to that of gravity die casting. The hypoeutectic open-cell Al-Si foams with 44 vol.% NaCl using squeeze casting showed the best properties among all foams due to its moderate and well-distributed porosity.

Oblique Impact on Crashworthiness: Review

This paper reviewed the crashworthiness of foam-filled thin-walled structure subjected to oblique loading conditions. Crashworthiness is the most important part in designing a safety vehicle, so, the types of collisions, crashworthiness parameter and the modes of collapse of structural components are included in this part. Secondly, the energy absorber regarding the axial loading and oblique loading in terms of geometry parameters and materials of the previous research is reviewed. In addition, the manufacturing and properties of aluminium foams with the collapse behavior of foam-filled structures are studied to understand the performance and the relation under loading.

Quasi-Static Compressive Characteristics of Cu-Containing Closed-Cell Aluminum Foams

Closed-cell aluminum foam with different percentages of Cu was prepared by melt foaming method.The effect of Cu element on the quasi-static compressive properties of aluminum foam was investigated, both under as-cast and heat-treated conditions. The results showed that Cu element distributed in cell wall matrix mainly in the forms of Al-Cu solid solutions and AlCu3, Al6.1Cu1.2Ti2.7 intermetallics. Meanwhile, Cu-containing foams possessed much higher compressive strength than the commercially pure aluminum foams. Additionally, proper heat treatment could further improve the yield strength of Cu-containing foams and the effect of aging treatment was more obvious than the homogenizing heat treatment under the present conditions and the reasons were discussed.

Effect of Heat Treatment and Reinforcements on the Mechanical Properties of Closed Cell Al-Cu Alloy Foam

In this research work, closed aluminum foams produced by powder metallurgy method, the aging heat treatment was performed on samples to evaluate the effect of copper as an alloying element and TiB2 as reinforcement on the mechanical properties of aluminum foams. The results indicated that, in this alloy foam, TiB2 particles play minor role on the mechanical properties, while the aging heat treatment enhanced the mechanical properties of the foam samples dramatically. In addition, the size of age hardening precipitates was smaller than the external reinforcement.

Dissolution Method of Aluminum Foams Containing Mg Using Carbamide Space Holder

This study investigated the properties of aluminium foam containing Mg with various amount of space holder. Aluminum foam was fabricated using dissolution method with various amount of carbamide (20, 40 and 60 wt. %). Aluminum foam with 60 wt. % carbamide has the lowest density (0.68 g/cm3) and exhibited the highest porosity (74.97%). However, the results indicates that aluminum foam with 40 wt. % of carbamide have good compressive and energy absorption with acceptable density and porosity value.

Simulation Analysis for Static Fracture Properties of DCB Aluminum Foams Bonded with Mode III Type

This study aims to investigate static fracture properties on adhesive layers by conducting simulation static analysis by thickness. Simulation analysis result showed that all specimens at t=35mm, 45mm, and 55mm showed maximum reaction force at approximately 5mm of forced displacement. Simulation analysis showed that maximum reaction forces of specimen models were approximately 0.25kN at t=35mm, approximately 0.28kN at t=45mm, and approximately 0.5kN at 55m, respectively. As such, the maximum reaction forces of specimen models that occur had increasing tendency along with increasing thickness. The study results showed fracture properties of aluminum foam adhesive specimen models at their adhesive layers. Based on accumulated data, it is thought that the data on variables other than variables in this study may be acquired easily, and that the data would contribute to analyzing mechanical properties of DCB adhesive structures with mode III-type.

Characteristic of Modified Geometrical Open-Cell Aluminum Foam by Casting Replication Process

In this work, aluminium foams with modified geometry were successfully fabricated with a combination of dense and porous structure The main objective of this study were to determine the initial physical properties of aluminium foam with modified geometry in terms of density, porosity and morphology. Three different NaCl space holder sizes ranging from 1 mm to 3 mm were sieved and used to replicate the final pore size of aluminium foam. The samples were successfully produced through casting replication process. After densification, samples underwent water leaching in ultrasonic bath to remove completely the space holder. Results showed that porosity of the aluminium foam increased from 50 – 62% when the size of space holder was increased from 1 mm to 3 mm. The morphology showed clearly an integrated modified geometry between dense and inter-connected porous structure which is beneficial for applications that require combination properties of structural, thermal and mechanical properties.

Low Velocity Impact of Aluminium Foam - Glass Fibre Reinforced Plastic Sandwich Panels

Sandwich structures with metal foams core are widely used in various engineering applications due to their special properties of high-strength and high-stiffness to weight ratio when compared to the properties of pure material systems. Sandwich structures have the capability to resist impact loads which make them favorable for energy absorber application. The aim of this research is to investigate the impact properties of aluminium foam sandwiched with glass fibre reinforced plastic (GFRP). Drop weight impact test was conducted using hemispherical impactor tip at velocity of 6.7 m/s by striking the samples with and without face-sheets. The result showed that the GFRP and aluminium foam core sandwich panel exhibited promising energy absorption properties, corresponding to the highest specific energy absorption value observed.