scholarly journals Shaping of Aluminum Foam During Foaming of Precursor Using Steel Mesh with Various Opening Ratios

Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 223 ◽  
Author(s):  
Yoshihiko Hangai ◽  
Ryohei Nagahiro ◽  
Masataka Ohashi ◽  
Kenji Amagai ◽  
Takao Utsunomiya ◽  
...  
Keyword(s):  
Heating Rate ◽  
Aluminum Foam ◽  
Aluminum Foams ◽  
Steel Mesh ◽  
Pore Structures ◽  
Foaming Time

In this study, steel meshes with various opening ratios φ were used to shape aluminum foams during precursor foaming. The effect of φ on the heating rate and shape of the obtained aluminum foams was investigated. It was found that steel meshes with various opening ratios can be used to shape aluminum foam. There is no significant effect on the pore structures of the obtained aluminum foams when upward expansion is restricted during foaming, regardless of the value of φ. The meshes with higher φ clearly transfer the mesh pattern onto the surface of the aluminum foam but require a shorter foaming time. In contrast, the lower-φ meshes produce aluminum foams with a smoother surface but a longer foaming time is required.

Effects of Extrusion Methods and Powder Carriers on Powder Forming and Precursor Foaming Behavior in the Preparation Process of Aluminum Foam

2013 ◽  
Vol 634-638 ◽  
pp. 1734-1739 ◽  
Author(s):  
Zhi Qiang Guo ◽  
Xiang Li ◽  
Xiao Guang Yuan ◽  
Hong Jun Huang
Keyword(s):  
Aluminum Foam ◽  
Whole Body ◽  
Preparation Process ◽  
Aluminum Foams ◽  
Minimum Density ◽  
Pore Structures ◽  
Foaming Behavior ◽  
New Type ◽  
Powder Forming

Aluminum foam is a new type of material that can be used in many fields. Compaction conditions are the most important parameters that have influence on foam preparation process. So in this paper, detailed researches about extrusion methods and powder carriers are conducted. The results show that: compare with direct extrusion, pre-pressing can effectively eliminate the influences of hydrogen, obtain high density precursors. However, when the flank of the precursor is wrapped with copper, H2 can escape from the combination parts of Al and Cu, in early foaming stage. The minimum density is only 0.75g/cm3, pore structures are almost round and nearly no plateau borders exist, so the quality of aluminum foam is still poor. When there is no copper wrapped, an oxide layer can be formed in the whole body of the precursor and limit the escaping of H2. The minimum density can reach 0.45g/cm3, pore structures are polygonal with thin cell walls about 0.08mm. Thus high quality aluminum foams can be obtained by using pre-pressing and then extruding method and precursor sheet powder carrier.

scholarly journals Explosion Resistance of Three-Dimensional Mesoscopic Model of Complex Closed-Cell Aluminum Foam Sandwich Structure Based on Random Generation Algorithm

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-16 ◽  
Author(s):  
Zhen Wang ◽  
Wen Bin Gu ◽  
Xing Bo Xie ◽  
Qi Yuan ◽  
Yu Tian Chen ◽  
...  
Keyword(s):  
Wall Thickness ◽  
Aluminum Foam ◽  
Three Dimensional ◽  
Coincidence Degree ◽  
Aluminum Foams ◽  
Polyhedral Particles ◽  
Mesh Model ◽  
Closed Cell ◽  
Wall Deformation ◽  
Deformation Area

According to the randomness of the spatial distribution and shape of the internal cells of closed-cell foam aluminum and based on the Voronoi algorithm, we use ABAQUS to model the random polyhedrons of pore cells firstly. Then, the algorithm of generating aluminum foam with random pore size and random wall thickness is written by Python and Fortran, and the mesh model of random polyhedral particles and random wall thickness was established by the algorithm read in by TrueGrid software. Finally, the mesh model is impo rted into the LS-DYNA software to remove the random polyhedron part of the pore cell. Compared with the results of scanning electron microscopy and antiknock test, the morphology and properties of the model are close to those of the real aluminum foam material, and the coincidence degree is more than 91.4%. By means of numerical simulation, the mechanism of the wall deformation, destruction of closed-cell aluminum foams, and the rapid attenuation of explosion stress wave after the interference of reflection and transmission of bubbles were studied and revealed. It is found that aluminum foam deformation can be divided into four areas: collapse area, fracture area, plastic deformation area, and elastic deformation region. Therefore, the explosion resistance is directly related to the cell wall thickness and bubble size, and there is an optimal porosity rule for aluminum foam antiknock performance.

Dynamic Crushing of All-Metallic Corrugated Panels Filled With Close-Celled Aluminum Foams

2015 ◽  
Vol 82 (1) ◽  
Author(s):  
B. Yu ◽  
B. Han ◽  
C. Y. Ni ◽  
Q. C. Zhang ◽  
C. Q. Chen ◽  
...  
Keyword(s):  
Aluminum Foam ◽  
Sandwich Panel ◽  
Dominant Role ◽  
Sandwich Panels ◽  
Rate Sensitivity ◽  
Aluminum Foams ◽  
Foam Filling ◽  
Plastic Hardening ◽  
Insight Into

Under quasi-static uniaxial compression, inserting aluminum foams into the interstices of a metallic sandwich panel with corrugated core increased significantly both its peak crushing strength and energy absorption per unit mass. This beneficial effect diminished however if the foam relative density was relatively low or the compression velocity became sufficiently high. To provide insight into the varying role of aluminum foam filler with increasing compression velocity, the crushing response and collapse modes of all metallic corrugate-cored sandwich panels filled with close-celled aluminum foams were studied using the method of finite elements (FEs). The constraint that sandwich panels with and without foam filling had the same total weight was enforced. The effects of plastic hardening and strain rate sensitivity of the strut material as well as foam/strut interfacial debonding were quantified. Three collapse modes (quasi-static, transition, and shock modes) were identified, corresponding to different ranges of compression velocity. Strengthening due to foam insertion and inertial stabilization both acted to provide support for the struts against buckling. At relatively low compression velocities, the struts were mainly strengthened by the surrounding foam; at high compression velocities, inertia stabilization played a more dominant role than foam filling.

scholarly journals Dynamic Compressive Behaviors of Two-Layer Graded Aluminum Foams under Blast Loading

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1445 ◽  
Author(s):  
Minzu Liang ◽  
Xiangyu Li ◽  
Yuliang Lin ◽  
Kefan Zhang ◽  
Fangyun Lu
Keyword(s):  
Energy Absorption ◽  
Aluminum Foam ◽  
Blast Resistance ◽  
Blast Loading ◽  
Deformation Energy ◽  
Aluminum Foams ◽  
Conflicting Objectives ◽  
Energy Dissipated ◽  
Transmitted Impulse ◽  
Energy Absorbing

Experimental and numerical analyses were carried out to reveal the behaviors of two-layer graded aluminum foam materials for their dynamic compaction under blast loading. Blast experiments were conducted to investigate the deformation and densification wave formation of two-layer graded foams with positive and negative gradients. The shape of the stress waveform changed during the propagation process, and the time of edge rising was extended. Finite element models of two-layer graded aluminum foam were developed using the periodic Voronoi technique. Numerical analysis was performed to simulate deformation, energy absorption, and transmitted impulse of the two-layer graded aluminum foams by the software ABAQUS/Explicit. The deformation patterns were presented to provide insights into the influences of the foam gradient on compaction wave mechanisms. Results showed that the densification wave occurred at the blast end and then gradually propagated to the distal end for the positive gradient; however, compaction waves simultaneously formed in both layers and propagated to the distal end in the same direction for the negative gradient. The energy absorption and impulse transfer were examined to capture the effect of the blast pressure and the material gradient. The greater the foam gradient, the more energy dissipated and the more impulse transmitted. The absorbed energy and transferred impulse are conflicting objectives for the blast resistance capability of aluminum foam materials with different gradient distributions. The results could help in understanding the performance and mechanisms of two-layer graded aluminum foam materials under blast loading and provide a guideline for effective design of energy-absorbing materials and structures.

scholarly journals Quasi-Static Compression Deformation and Energy Absorption Characteristics of Basalt Fiber-Containing Closed-Cell Aluminum Foam

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 921 ◽  
Author(s):  
Donghui Yang ◽  
Zichen Zhang ◽  
Xueguang Chen ◽  
Xing Han ◽  
Tao Xu ◽  
...  
Keyword(s):  
Pore Size ◽  
Energy Absorption ◽  
Cell Walls ◽  
Aluminum Foam ◽  
Pure Aluminum ◽  
Present Condition ◽  
Aluminum Foams ◽  
Commercially Pure ◽  
Closed Cell ◽  
Absorption Characteristics

In this work, closed-cell aluminum foams with 4 wt.% contents of short-cut basalt fibers (BFs) were successful prepared by using the modified melt-foaming method. The pore size of BF-containing aluminum foam and commercially pure aluminum foam was counted. The distribution of BF and its effect on the compressive properties of closed-cell aluminum foams were investigated. The results showed that the pore size of BF-containing aluminum foams was more uniform and smaller. BF mainly existed in three different forms: Some were totally embedded in the cell walls, some protruded from the cell walls, and others penetrated through the cells. Meanwhile, under the present condition, BF-containing aluminum foams possessed higher compressive strength and energy absorption characteristics than commercially pure aluminum foams, and the reasons were discussed.

scholarly journals Anisotropic Compressive Behavior of Functionally Density Graded Aluminum Foam Prepared by Controlled Melt Foaming Process

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2470 ◽  
Author(s):  
Bingbing Zhang ◽  
Shuangqi Hu ◽  
Zhiqiang Fan
Keyword(s):  
Energy Absorption ◽  
Aluminum Foam ◽  
Image Correlation ◽  
Lateral Strain ◽  
Transverse Compression ◽  
Deformation Bands ◽  
Aluminum Foams ◽  
Static Compression ◽  
Plateau Stress ◽  
Foaming Process

Aluminum foams with a functionally graded density have exhibited better impact resistance and a better energy absorbing performance than aluminum foams with a uniform density. Nevertheless, the anisotropic compression behavior caused by the graded density has scarcely been studied. In this paper, a density graded aluminum foam (FG) was prepared by a controlled foaming process. The effect of density anisotropy on the mechanical behavior of FGs was investigated under quasi-static compression and a low-velocity impact. Digital image correlation (DIC) and numerical simulation techniques were used to identify deformation mechanisms at both macro and cell levels. Results show that transverse compression on FGs lead to a higher collapse strength but also to a lower energy absorption, due to the significant decrease in densification strain and plateau stress. The deformation behavior of FGs under longitudinal compression was dominated by the progressive extension of the deformation bands. For FGs under transverse compression, the failure mode of specimens was characterized by multiple randomly distributed deformation bands. Moreover, the transverse compression caused more deformation on cells, through tearing and lateral stretching, because of the high lateral strain level in the specimens. It was concluded that the transverse compression of FGs lead to a lower plateau stress and a lower cell usage, thus resulting in a poorer energy absorption efficient; this constitutes a key factor which should be taken into consideration in structural design.

Application of Superplastic Flow to Manufacturing of Microcellular Aluminum Foams

2005 ◽  
Vol 475-479 ◽  
pp. 3021-3024 ◽  
Author(s):  
Shinya Kamimura ◽  
Koichi Kitazono ◽  
Eiichi Sato ◽  
Kazuhiko Kuribayashi
Keyword(s):  
Thermal Conductivity ◽  
Cell Shape ◽  
Aluminum Foam ◽  
Oblate Spheroid ◽  
Metal Foams ◽  
Aluminum Foams ◽  
Roll Bonding ◽  
Heat Insulator ◽  
5083 Aluminum Alloy ◽  
Superplastic Condition

A new application of superplasticity was proposed in the manufacturing process of metal foams. Preform sheets were manufactured using superplastic 5083 aluminum alloy sheets through accumulative roll-bonding (ARB) process. Microcellular aluminum foam plates with 50% porosity were produced through solid-state foaming under the superplastic condition. The cell shape was oblate spheroid, which is effective to reduce the thermal conductivity. The present aluminum foam plates have a potential as an excellent heat insulator.

Improvement of Pore Structures of Aluminum Foam Composite Fabricated Using Optical Heating

2019 ◽  
Vol 2019 (0) ◽  
pp. OS1607
Author(s):  
Gota ARAI ◽  
Takao UTUNOMIYA ◽  
Yoshihiko HANGAI ◽  
Kenji AMAGAI ◽  
Sinji HASHIMURA
Keyword(s):  
Aluminum Foam ◽  
Pore Structures ◽  
Optical Heating ◽  
Foam Composite

Self-Blowing Process of Al Foam Assisted by Exothermic Reaction

2006 ◽  
Vol 519-521 ◽  
pp. 1335-1340 ◽  
Author(s):  
Makoto Kobashi ◽  
Naoyuki Kanetake
Keyword(s):  
Aluminum Foam ◽  
Liquid Aluminum ◽  
Exothermic Reaction ◽  
External Source ◽  
Processing Parameters ◽  
Hydrogen Gas ◽  
Heat Of Reaction ◽  
Aluminum Foams ◽  
Gas Generation ◽  
Reactive Powder

Aluminum foam is a class of porous materials; in which closed pores are produced by a gas generation in liquid (or semi-liquid) aluminum. Aluminum foams are, generally, fabricated by heating a foamable precursor (a powder compact consisting of aluminum and TiH2 powders). Decomposition of TiH2, which is followed by a hydrogen gas release, produces bubbles in molten aluminum. In this research, aluminum foam was fabricated with the help of a chemical exothermic reaction. Titanium and boron carbide (B4C) powders were blended in the Al-TiH2 precursor as reactive powder elements. When one end of the precursor was heated, a strong exothermic reaction between titanium and B4C took place (3Ti + B4C 􀃆 2TiB2 +TiC + 761KJ), and the neighboring part of the precursor was heated by the heat of reaction. Hence, once the reaction happens at the end of the precursor, it propagates spontaneously throughout the precursor. The blowing process takes place at the same time as the reaction because aluminum melts and TiH2 decomposes by the heat of reaction. The advantage of this process is that the energy to make aluminum foam is not necessarily supplied form the external source, but generated form inside of the precursor. Therefore the blowing process is self sustainable (Self-Blowing Process). In this work, the effect of processing parameters on the Self-Blowing Process was observed. The processing parameters we focused on were blending ratio of the starting powders (aluminum, TiH2, titanium, B4C) and heating methods.

scholarly journals Torsion Property of the Structure Bonded Aluminum Foam Due to Impact

2017 ◽  
Vol 62 (2) ◽  
pp. 1353-1357
Author(s):  
G.W. Hwang ◽  
J.U. Cho
Keyword(s):  
Impact Energy ◽  
Aluminum Foam ◽  
Bonding Interface ◽  
Cell Type ◽  
Aluminum Foams ◽  
Fracture Characteristics ◽  
Foaming Agent ◽  
Closed Cell ◽  
The Impact ◽  
Torsion Property

AbstractAn aluminum foam added with foaming agent, is classified into an open-cell type for heat transfer and a closed-cell type for shock absorption. This study investigates the characteristic on the torsion of aluminum foam for a closed-cell type under impact. The fracture characteristics are investigated through the composite of five types of aluminum foam (the thicknesses of 25, 35, 45, 55 and 65 mm), when applying the torsional moment of impact energy on the junction of a porous structure attached by an adhesive. When applying the impact energy of 100, 200 and 300J, the aluminum foams with thicknesses of 25 mm and 35 mm broke off under all conditions. For the energy over 200J, aluminums thicker than 55 mm continued to be attached. Furthermore, the aluminum specimens with thicknesses of 55 mm and 65 mm that were attached with more than 30% of bonding interface remained, proving that they could maintain bonding interface against impact energy. By comparing the data based on the analysis and test result, an increase in the thickness of specimen leads to the plastic deformation as the stress at the top and bottom of bonding interface moves to the middle by spreading the stress horizontally. Based on this fracture characteristic, this study can provide the data on the destruction and separation of bonding interface and may contribute to the safety design.

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